Ocean Teacher Library - New pages [en]

Charlessun

2012-04-27T11:58:27Z

WikiSysop: Created page with "{{User |name=Charles Sun |role=Contributor, Editor |email=charles.sun@noaa.gov }}"

{{User
|name=Charles Sun
|role=Contributor, Editor
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BUFR Quality Information, Replaced Values

2012-03-05T14:15:31Z

Bob.keeley: moved BUFR Quality Information, Replaced Values to 15. BUFR Quality Information, Replaced Values: To provide for a correct ordering of documents in this section

BUFR First Order Statistics

2012-03-05T14:06:33Z

Bob.keeley: moved BUFR First Order Statistics to 14. BUFR First Order Statistics: To provide for a correct ordering of documents in this section

{{ContentHeader}}

Refer to the “Layer 3” [http://www.wmo.int/pages/prog/www/WMOCodes/Guides/BUFRCREXPreface_en.html document] at WMO, section 3.1.6.7

== Sample Content ==

Suppose there are 10 measurements of a sea temperature in the upper 100m of the ocean and that it is desired to provide the average temperature as well as standard deviation. Let the values be as follows. A data present bit map is used to indicate that there is a missing values. These values are also shown. A value present is signified by “0” in the bit map.
<center>
{| border="1" cellpadding="4" cellspacing="0" width="212"
|- valign="TOP"
| width="40" | Depth
| width="84" | Temperature(degrees C)
| width="62" | Bit map
|- valign="TOP"
| width="40" | 0
| width="84" | 15.4
| width="62" | 0
|- valign="TOP"
| width="40" | 10
| width="84" | 15.3
| width="62" | 0
|- valign="TOP"
| width="40" | 20
| width="84" | missing
| width="62" | 1
|- valign="TOP"
| width="40" | 30
| width="84" | 15.2
| width="62" | 0
|- valign="TOP"
| width="40" | 40
| width="84" | 15
| width="62" | 0
|- valign="TOP"
| width="40" | 50
| width="84" | 14.6
| width="62" | 0
|- valign="TOP"
| width="40" | 60
| width="84" | 13.8
| width="62" | 0
|- valign="TOP"
| width="40" | 70
| width="84" | 12.5
| width="62" | 0
|- valign="TOP"
| width="40" | 80
| width="84" | 10.3
| width="62" | 0
|- valign="TOP"
| width="40" | 90
| width="84" | 10.1
| width="62" | 0
|- valign="TOP"
| width="40" | 100
| width="84" | 9.9
| width="62" | 0
|}
</center>
 Since we wish to deliver a mean and standard deviation, we use BUFR code table 0 08 023 and select code value “4” for mean, and code value “10” for standard deviation. The mean value is 13.19 and standard deviation is 0.66.
<center>
{| border="1" cellpadding="4" cellspacing="0" width="472"
|- valign="TOP"
| width="35" |
Depth

| width="128" | Depth value in 17 bits
| width="77" | Temperature(degrees C)
| width="76" | Temperature(degrees K)
| width="114" | Temperature value in15 bits
|- valign="TOP"
| width="35" |
0

| width="128" | 00000000000000000
| width="77" | 15.4
| width="76" | 288.55
| width="114" | 111000010110111
|- valign="TOP"
| width="35" |
10

| width="128" | 00000000001100100
| width="77" | 15.3
| width="76" | 288.45
| width="114" | 111000010101101
|- valign="TOP"
| width="35" |
20

| width="128" | 00000000011001000
| width="77" | missing
| width="76" | missing
| width="114" | 111111111111111
|- valign="TOP"
| width="35" |
30

| width="128" | 00000000100101100
| width="77" | 15.2
| width="76" | 288.35
| width="114" | 111000010100011
|- valign="TOP"
| width="35" |
40

| width="128" | 00000000110010000
| width="77" | 15
| width="76" | 288.15
| width="114" | 111000010001111
|- valign="TOP"
| width="35" |
50

| width="128" | 00000000111110100
| width="77" | 14.6
| width="76" | 287.75
| width="114" | 111000001100111
|- valign="TOP"
| width="35" |
60

| width="128" | 00000001001011000
| width="77" | 13.8
| width="76" | 286.95
| width="114" | 111000000010111
|- valign="TOP"
| width="35" |
70

| width="128" | 00000001010111100
| width="77" | 12.5
| width="76" | 285.65
| width="114" | 110111110010101
|- valign="TOP"
| width="35" |
80

| width="128" | 00000001100100000
| width="77" | 10.3
| width="76" | 283.45
| width="114" | 110111010111001
|- valign="TOP"
| width="35" |
90

| width="128" | 00000001110000100
| width="77" | 10.1
| width="76" | 283.25
| width="114" | 110111010100101
|- valign="TOP"
| width="35" |
100

| width="128" | 00000001111101000
| width="77" | 9.9
| width="76" | 283.05
| width="114" | 110111010010001
|}
</center>
 Remember that depth values are scaled by 1, therefore recorded to decimeters, and temperatures are in degrees K and scaled by 2, therefore recorded to 100ths of degrees.

Here are the BUFR descriptors to be used. This is a stripped down version of what a full message might look like.

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="53" | FXY
| width="271" |
Meaning

| width="30" | Bits
| width="59" | Value (decimal)
| width="42" | Raw Value
| width="124" | Binary
| width="28" | Note
|- valign="TOP"
| width="53" | 0 01 005
| width="271" |
Buoy/platform identifier

| width="30" | 17
| width="59" | 55824
| width="42" | 
| width="124" | 01101101000010000
| width="28" | 
|- valign="TOP"
| width="53" | 0 05 002
| width="271" |
Latitude (coarse accuracy)

| width="30" | 15
| width="59" | 46.75 N
| width="42" | 13675
| width="124" | 011010101101011
| width="28" | 1
|- valign="TOP"
| width="53" | 0 06 002
| width="271" |
Longitude (coarse accuracy)

| width="30" | 16
| width="59" | 62.89 W
| width="42" | 11711
| width="124" | 0010110110111111
| width="28" | 1
|- valign="TOP"
| width="53" | 0 04 001
| width="271" |
Year

| width="30" | 12
| width="59" | 2010
| width="42" | 
| width="124" | 011111011010
| width="28" | 
|- valign="TOP"
| width="53" | 0 04 002
| width="271" |
Month

| width="30" | 4
| width="59" | 3
| width="42" | 
| width="124" | 0011
| width="28" | 
|- valign="TOP"
| width="53" | 0 04 003
| width="271" |
Day

| width="30" | 6
| width="59" | 24
| width="42" | 
| width="124" | 011000
| width="28" | 
|- valign="TOP"
| width="53" | 0 04 004
| width="271" |
Hour

| width="30" | 5
| width="59" | 22
| width="42" | 
| width="124" | 10110
| width="28" | 
|- valign="TOP"
| width="53" | 0 04 005
| width="271" |
Minute

| width="30" | 6
| width="59" | 34
| width="42" | 
| width="124" | 100010
| width="28" | 
|- valign="TOP"
| width="53" | 1 01 011
| width="271" |
Replicate 1 descriptor, 11 times

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 0 07 062
| width="271" |
Depth below sea/water surface (11 values delivered)

| width="30" | 17
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 1 01 011
| width="271" |
Replicate 1 descriptor, 11 times

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 0 22 043
| width="271" |
Sea/water temperature (11 values delivered)

| width="30" | 15
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 000
| width="271" |
First order statistics follow

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 2 36 000
| width="271" |
Define a data present bit map

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 1 01 011
| width="271" |
Replicate to indicate 1 descriptor with 11 values (the bit map)

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 0 31 031
| width="271" |
The bit map

| width="30" | 11
| width="59" | 
| width="42" | 
| width="124" | 00100000000
| width="28" | 
|- valign="TOP"
| width="53" | 0 08 023
| width="271" |
Mean

| width="30" | 6
| width="59" | 4
| width="42" | 
| width="124" | 000100
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 0 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 2
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 10 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 20 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 30 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 40 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 50 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 60 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 70 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 80 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 90 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Mean temperature for depth 100 m

| width="30" | 15
| width="59" | 13.2
| width="42" | 28635
| width="124" | 110111111011011
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 000
| width="271" |
First order statistics follow

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 2 36 000
| width="271" |
Define a data present bit map

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 1 01 011
| width="271" |
Replicate to indicate 1 descriptor with 11 values (the bit map)

| width="30" | 0
| width="59" | 
| width="42" | 
| width="124" | 
| width="28" | 
|- valign="TOP"
| width="53" | 0 31 031
| width="271" |
The bit map

| width="30" | 11
| width="59" | 
| width="42" | 
| width="124" | 00100000000
| width="28" | 3
|- valign="TOP"
| width="53" | 0 08 023
| width="271" |
Standard deviation

| width="30" | 6
| width="59" | 10
| width="42" | 
| width="124" | 001010
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 0 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 4
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 10 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 20 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 30 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 40 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 50 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 60 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 70 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 80 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 90 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|- valign="TOP"
| width="53" | 2 24 255
| width="271" |
Standard deviation of temperature for depth 100 m

| width="30" | 15
| width="59" | 0.66
| width="42" | 27381
| width="124" | 110101011110101
| width="28" | 
|}

Note

#Latitudes and longitudes have a scale of 2 and non-zero reference values. See the document “BUFR SYNOP”.
#Temperature is reported to degrees K with a scale of 2 (therefore to 2 decimals) and a reference of 0 (so add 273.15 to the value).
#Where the bit map is repeated it is possible to indicate that the previously defined bit map is to be used. In this case 0 08 023 would be replaced (in this row) by the operator 2 37 000. There would also be changes in how sections 3 and 4 would be constructed. These differences are not shown here.
#Standard deviation of temperature is reported to the same units as the variable, therefore in degrees K with a scale of 2 (therefore to 2 decimals) and a reference of 0 (so add 273.15 to the value). See the note after BUFR code tables 0 08 023.

== BUFR encoding ==

Section 3

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="48" | '''Section'''
| width="63" | '''Octet No.'''
| width="67" | '''Binary'''
| width="82" | '''Hexadecimal'''
| width="67" | '''Decoded'''
| width="288" |
'''Description'''

|- valign="TOP"
| width="48" | 3
| width="63" | 1
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="3" width="288" |
Length of section (octets)

|- valign="TOP"
| width="48" | 3
| width="63" | 2
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
|- valign="TOP"
| width="48" | 3
| width="63" | 3
| width="67" | 01100000
| width="82" | 60
| width="67" | 96
|- valign="TOP"
| width="48" | 3
| width="63" | 4
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Reserved. Set to zero.

|- valign="TOP"
| width="48" | 3
| width="63" | 5
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="2" width="288" |
Number of subsets

|- valign="TOP"
| width="48" | 3
| width="63" | 6
| width="67" | 00000001
| width="82" | 1
| width="67" | 1
|- valign="TOP"
| width="48" | 3
| width="63" | 7
| width="67" | 00000001
| width="82" | 1
| width="67" | 1
| width="288" |
Observed data

|- valign="TOP"
| width="48" | 3
| width="63" | 8
| width="67" | 00000001
| width="82" | 4
| width="67" | 0 01
| rowspan="2" width="288" |
Buoy/platform identifier

|- valign="TOP"
| width="48" | 3
| width="63" | 9
| width="67" | 00000101
| width="82" | 5
| width="67" | 005
|- valign="TOP"
| width="48" | 3
| width="63" | 10
| width="67" | 00000101
| width="82" | 5
| width="67" | 0 05
| rowspan="2" width="288" |
Latitude (coarse accuracy)

|- valign="TOP"
| width="48" | 3
| width="63" | 11
| width="67" | 00000010
| width="82" | 2
| width="67" | 002
|- valign="TOP"
| width="48" | 3
| width="63" | 12
| width="67" | 00000110
| width="82" | 6
| width="67" | 0 06
| rowspan="2" width="288" |
Longitude (coarse accuracy)

|- valign="TOP"
| width="48" | 3
| width="63" | 13
| width="67" | 00000010
| width="82" | 2
| width="67" | 002
|- valign="TOP"
| width="48" | 3
| width="63" | 14
| width="67" | 00000100
| width="82" | 4
| width="67" | 0 04
| rowspan="2" width="288" |
Year

|- valign="TOP"
| width="48" | 3
| width="63" | 15
| width="67" | 00000001
| width="82" | 1
| width="67" | 001
|- valign="TOP"
| width="48" | 3
| width="63" | 16
| width="67" | 00000100
| width="82" | 4
| width="67" | 0 04
| rowspan="2" width="288" |
Month

|- valign="TOP"
| width="48" | 3
| width="63" | 17
| width="67" | 00000010
| width="82" | 2
| width="67" | 002
|- valign="TOP"
| width="48" | 3
| width="63" | 18
| width="67" | 00000100
| width="82" | 4
| width="67" | 0 04
| rowspan="2" width="288" |
Day

|- valign="TOP"
| width="48" | 3
| width="63" | 19
| width="67" | 00000011
| width="82" | 3
| width="67" | 003
|- valign="TOP"
| width="48" | 3
| width="63" | 20
| width="67" | 00000100
| width="82" | 4
| width="67" | 0 04
| rowspan="2" width="288" |
Hour

|- valign="TOP"
| width="48" | 3
| width="63" | 21
| width="67" | 00000100
| width="82" | 4
| width="67" | 004
|- valign="TOP"
| width="48" | 3
| width="63" | 22
| width="67" | 00000100
| width="82" | 4
| width="67" | 0 04
| rowspan="2" width="288" |
Minute

|- valign="TOP"
| width="48" | 3
| width="63" | 23
| width="67" | 00000101
| width="82" | 5
| width="67" | 005
|- valign="TOP"
| width="48" | 3
| width="63" | 24
| width="67" | 01000001
| width="82" | 41
| width="67" | 1 01
| rowspan="2" width="288" |
Replicate 1 descriptor, 11 times

|- valign="TOP"
| width="48" | 3
| width="63" | 25
| width="67" | 00001011
| width="82" | B
| width="67" | 011
|- valign="TOP"
| width="48" | 3
| width="63" | 26
| width="67" | 00000111
| width="82" | 7
| width="67" | 0 07
| rowspan="2" width="288" |
Depth below sea/water surface

|- valign="TOP"
| width="48" | 3
| width="63" | 27
| width="67" | 00111110
| width="82" | 3E
| width="67" | 062
|- valign="TOP"
| width="48" | 3
| width="63" | 28
| width="67" | 01000001
| width="82" | 41
| width="67" | 1 01
| rowspan="2" width="288" |
Replicate 1 descriptor, 11 times

|- valign="TOP"
| width="48" | 3
| width="63" | 29
| width="67" | 00001011
| width="82" | B
| width="67" | 011
|- valign="TOP"
| width="48" | 3
| width="63" | 30
| width="67" | 00010110
| width="82" | 16
| width="67" | 0 22
| rowspan="2" width="288" |
Sea/water temperature

|- valign="TOP"
| width="48" | 3
| width="63" | 31
| width="67" | 00101011
| width="82" | 2B
| width="67" | 043
|- valign="TOP"
| width="48" | 3
| width="63" | 32
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
First order statistics follow

|- valign="TOP"
| width="48" | 3
| width="63" | 33
| width="67" | 00000000
| width="82" | 0
| width="67" | 000
|- valign="TOP"
| width="48" | 3
| width="63" | 34
| width="67" | 10100100
| width="82" | A4
| width="67" | 2 36
| rowspan="2" width="288" |
Define a data present bit map

|- valign="TOP"
| width="48" | 3
| width="63" | 35
| width="67" | 00000000
| width="82" | 0
| width="67" | 000
|- valign="TOP"
| width="48" | 3
| width="63" | 36
| width="67" | 01000001
| width="82" | 41
| width="67" | 1 01
| rowspan="2" width="288" |
Replicate 1 descriptor, 11 times

|- valign="TOP"
| width="48" | 3
| width="63" | 37
| width="67" | 00001011
| width="82" | B
| width="67" | 011
|- valign="TOP"
| width="48" | 3
| width="63" | 38
| width="67" | 00011111
| width="82" | 1F
| width="67" | 0 31
| rowspan="2" width="288" |
The bit map

|- valign="TOP"
| width="48" | 3
| width="63" | 39
| width="67" | 00011111
| width="82" | 1F
| width="67" | 031
|- valign="TOP"
| width="48" | 3
| width="63" | 40
| width="67" | 00001000
| width="82" | 8
| width="67" | 0 08
| rowspan="2" width="288" |
Mean

|- valign="TOP"
| width="48" | 3
| width="63" | 41
| width="67" | 00010111
| width="82" | 17
| width="67" | 023
|- valign="TOP"
| width="48" | 3
| width="63" | 42
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 0 m

|- valign="TOP"
| width="48" | 3
| width="63" | 43
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 44
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 10 m

|- valign="TOP"
| width="48" | 3
| width="63" | 45
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 46
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 20 m

|- valign="TOP"
| width="48" | 3
| width="63" | 47
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 48
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 30 m

|- valign="TOP"
| width="48" | 3
| width="63" | 49
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 50
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 40 m

|- valign="TOP"
| width="48" | 3
| width="63" | 51
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 52
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 50 m

|- valign="TOP"
| width="48" | 3
| width="63" | 53
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 54
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 60 m

|- valign="TOP"
| width="48" | 3
| width="63" | 55
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 56
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 70 m

|- valign="TOP"
| width="48" | 3
| width="63" | 57
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 58
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 80 m

|- valign="TOP"
| width="48" | 3
| width="63" | 59
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 60
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 90 m

|- valign="TOP"
| width="48" | 3
| width="63" | 61
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 62
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 100 m

|- valign="TOP"
| width="48" | 3
| width="63" | 63
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 64
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
First order statistics follow

|- valign="TOP"
| width="48" | 3
| width="63" | 65
| width="67" | 00000000
| width="82" | 0
| width="67" | 000
|- valign="TOP"
| width="48" | 3
| width="63" | 66
| width="67" | 10100100
| width="82" | A4
| width="67" | 2 36
| rowspan="2" width="288" |
Define a data present bit map

|- valign="TOP"
| width="48" | 3
| width="63" | 67
| width="67" | 00000000
| width="82" | 0
| width="67" | 000
|- valign="TOP"
| width="48" | 3
| width="63" | 68
| width="67" | 01000001
| width="82" | 41
| width="67" | 1 01
| rowspan="2" width="288" |
Replicate 1 descriptor, 11 times

|- valign="TOP"
| width="48" | 3
| width="63" | 69
| width="67" | 00001011
| width="82" | B
| width="67" | 011
|- valign="TOP"
| width="48" | 3
| width="63" | 70
| width="67" | 00011111
| width="82" | 1F
| width="67" | 0 31
| rowspan="2" width="288" |
The bit map

|- valign="TOP"
| width="48" | 3
| width="63" | 71
| width="67" | 00011111
| width="82" | 1F
| width="67" | 031
|- valign="TOP"
| width="48" | 3
| width="63" | 72
| width="67" | 00001000
| width="82" | 8
| width="67" | 0 08
| rowspan="2" width="288" |
Standard deviation

|- valign="TOP"
| width="48" | 3
| width="63" | 73
| width="67" | 00010111
| width="82" | 17
| width="67" | 023
|- valign="TOP"
| width="48" | 3
| width="63" | 74
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 0 m

|- valign="TOP"
| width="48" | 3
| width="63" | 75
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 76
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 10 m

|- valign="TOP"
| width="48" | 3
| width="63" | 77
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 78
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 20 m

|- valign="TOP"
| width="48" | 3
| width="63" | 79
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 80
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 30 m

|- valign="TOP"
| width="48" | 3
| width="63" | 81
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 82
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 40 m

|- valign="TOP"
| width="48" | 3
| width="63" | 83
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 84
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 50 m

|- valign="TOP"
| width="48" | 3
| width="63" | 85
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 86
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 60 m

|- valign="TOP"
| width="48" | 3
| width="63" | 87
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 88
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 70 m

|- valign="TOP"
| width="48" | 3
| width="63" | 89
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 90
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 80 m

|- valign="TOP"
| width="48" | 3
| width="63" | 91
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 92
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 90 m

|- valign="TOP"
| width="48" | 3
| width="63" | 93
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 94
| width="67" | 10011000
| width="82" | 98
| width="67" | 2 24
| rowspan="2" width="288" |
Depth 100 m

|- valign="TOP"
| width="48" | 3
| width="63" | 95
| width="67" | 11111111
| width="82" | FF
| width="67" | 255
|- valign="TOP"
| width="48" | 3
| width="63" | 96
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Zero fill to complete an even number of octets

|}

Section 4

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="48" | '''Section'''
| width="63" | '''Octet No.'''
| width="67" | '''Binary'''
| width="82" | '''Hexadecimal'''
| width="67" | '''Decoded'''
| width="288" |
'''Description'''

|- valign="TOP"
| width="48" | 4
| width="63" | 1
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="3" width="288" |
Length of section (octets). This must include the additional bits needed for the local descriptor.

|- valign="TOP"
| width="48" | 4
| width="63" | 2
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
|- valign="TOP"
| width="48" | 4
| width="63" | 3
| width="67" | 01101000
| width="82" | 68
| width="67" | 104
|- valign="TOP"
| width="48" | 4
| width="63" | 4
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Reserved

|- valign="TOP"
| width="48" | 4
| width="63" | 5
| width="67" | '''01101101'''
| width="82" | 6D
| width="67" | 109
| width="288" |
Continuous stream of bits starting with Buoy/platform identifier (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 6
| width="67" | '''00001000'''
| width="82" | 8
| width="67" | 8
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 7
| width="67" | '''0'''''0110101''
| width="82" | 35
| width="67" | 53
| width="288" |
Latitude (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 8
| width="67" | ''01101011''
| width="82" | 6B
| width="67" | 107
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 9
| width="67" | '''00101101'''
| width="82" | 1D
| width="67" | 29
| width="288" |
Longitude (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 10
| width="67" | '''10111111'''
| width="82" | BC
| width="67" | 188
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 11
| width="67" | ''01111101''
| width="82" | 7D
| width="67" | 125
| width="288" |
Year (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 12
| width="67" | ''1010'''''0011'''
| width="82" | A3
| width="67" | 163
| width="288" |
Month (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 13
| width="67" | ''011000'''''10'''
| width="82" | 62
| width="67" | 98
| width="288" |
Day (italic) followed by Hour (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 14
| width="67" | '''110'''''10001''
| width="82" | D1
| width="67" | 209
| width="288" |
Minute (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 15
| width="67" | ''0'''''0000000'''
| width="82" | 0
| width="67" | 0
| width="288" |
Depth of 0 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 16
| width="67" | '''00000000'''
| width="82" | 0
| width="67" | 0
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 17
| width="67" | '''00'''''111000''
| width="82" | 38
| width="67" | 56
| width="288" |
Temperature at 0 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 18
| width="67" | ''01011011''
| width="82" | 5B
| width="67" | 91
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 19
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 10 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 20
| width="67" | '''00011001'''
| width="82" | 19
| width="67" | 25
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 21
| width="67" | '''00'''''111000''
| width="82" | 38
| width="67" | 56
| width="288" |
Temperature at 10 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 22
| width="67" | ''01010110''
| width="82" | 56
| width="67" | 86
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 23
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 20 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 24
| width="67" | '''01100100'''
| width="82" | 64
| width="67" | 100
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 25
| width="67" | '''''00'''''''111111''
| width="82" | 3F
| width="67" | 63
| width="288" |
Temperature at 20 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 26
| width="67" | ''11111111''
| width="82" | FF
| width="67" | 255
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 27
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 30 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 28
| width="67" | '''01001011'''
| width="82" | 4B
| width="67" | 75
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 29
| width="67" | '''00'''''111000''
| width="82" | 38
| width="67" | 56
| width="288" |
Temperature at 30 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 30
| width="67" | ''01010001''
| width="82" | 51
| width="67" | 81
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 31
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 40 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 32
| width="67" | '''01100100'''
| width="82" | 64
| width="67" | 100
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 33
| width="67" | '''00'''''111000''
| width="82" | 38
| width="67" | 56
| width="288" |
Temperature at 40 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 34
| width="67" | ''01000111''
| width="82" | 48
| width="67" | 72
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 35
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 50 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 36
| width="67" | '''01111101'''
| width="82" | 7D
| width="67" | 125
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 37
| width="67" | '''00'''''111000''
| width="82" | 38
| width="67" | 56
| width="288" |
Temperature at 50 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 38
| width="67" | ''00110011''
| width="82" | 33
| width="67" | 51
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 39
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 60 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 40
| width="67" | '''10010110'''
| width="82" | 90
| width="67" | 144
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 41
| width="67" | '''00'''''111000''
| width="82" | 38
| width="67" | 56
| width="288" |
Temperature at 60 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 42
| width="67" | ''00001011''
| width="82" | B
| width="67" | 11
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 43
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 70 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 44
| width="67" | '''10101111'''
| width="82" | AF
| width="67" | 175
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 45
| width="67" | '''00'''''110111''
| width="82" | 37
| width="67" | 55
| width="288" |
Temperature at 70 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 46
| width="67" | ''11001010''
| width="82" | CA
| width="67" | 202
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 47
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 80 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 48
| width="67" | '''11001000'''
| width="82" | C8
| width="67" | 200
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 49
| width="67" | '''00'''''110111''
| width="82" | 37
| width="67" | 55
| width="288" |
Temperature at 80 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 50
| width="67" | ''01011100''
| width="82" | 5C
| width="67" | 92
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 51
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 90 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 52
| width="67" | '''11100001'''
| width="82" | E1
| width="67" | 225
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 53
| width="67" | '''00'''''110111''
| width="82" | 37
| width="67" | 55
| width="288" |
Temperature at 90 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 54
| width="67" | ''01010010''
| width="82" | 52
| width="67" | 82
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 55
| width="67" | ''1'''''0000000'''
| width="82" | 80
| width="67" | 128
| width="288" |
Depth of 100 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 56
| width="67" | '''11111010'''
| width="82" | FA
| width="67" | 250
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 57
| width="67" | '''00'''''110111''
| width="82" | 37
| width="67" | 55
| width="288" |
Temperature at 100 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 58
| width="67" | ''01001000''
| width="82" | 48
| width="67" | 72
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 59
| width="67" | ''1'''''0010000'''
| width="82" | 98
| width="67" | 152
| width="288" |
The bit map (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 60
| width="67" | '''0000'''''0001''
| width="82" | 1
| width="67" | 1
| width="288" |
Mean values to be delivered (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 61
| width="67" | ''00'''''110111'''
| width="82" | 37
| width="67" | 55
| width="288" |
Mean temperature for depth 0 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 62
| width="67" | '''11101101'''
| width="82" | ED
| width="67" | 237
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 63
| width="67" | '''1'''''1101111''
| width="82" | EF
| width="67" | 239
| width="288" |
Mean temperature for depth 10 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 64
| width="67" | ''11011011'''''1'''
| width="82" | D7
| width="67" | 215
| width="288" |
Mean temperature for depth 20 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 65
| width="67" | '''10111111'''
| width="82" | BF
| width="67" | 191
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 66
| width="67" | '''1011011'''''1''
| width="82" | B7
| width="67" | 183
| width="288" |
Mean temperature for depth 30 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 67
| width="67" | ''10111111''
| width="82" | BF
| width="67" | 191
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 68
| width="67" | ''1011011'''''1'''
| width="82" | B7
| width="67" | 183
| width="288" |
Mean temperature for depth 40 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 69
| width="67" | '''10111111'''
| width="82" | BF
| width="67" | 191
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 70
| width="67" | '''011011'''''11''
| width="82" | 6F
| width="67" | 111
| width="288" |
Mean temperature for depth 50 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 71
| width="67" | ''01111110''
| width="82" | 7E
| width="67" | 126
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 72
| width="67" | ''11011'''''110'''
| width="82" | DE
| width="67" | 222
| width="288" |
Mean temperature for depth 60 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 73
| width="67" | '''11111101'''
| width="82" | FD
| width="67" | 253
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 74
| width="67" | '''1011'''''1101''
| width="82" | BD
| width="67" | 189
| width="288" |
Mean temperature for depth 70 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 75
| width="67" | ''11111011''
| width="82" | FB
| width="67" | 251
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 76
| width="67" | ''011'''''11011'''
| width="82" | 7B
| width="67" | 123
| width="288" |
Mean temperature for depth 80 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 77
| width="67" | '''11110110'''
| width="82" | F6
| width="67" | 246
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 78
| width="67" | '''11'''''110111''
| width="82" | F7
| width="67" | 247
| width="288" |
Mean temperature for depth 90 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 79
| width="67" | ''11101101''
| width="82" | ED
| width="67" | 237
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 80
| width="67" | ''1'''''1101111'''
| width="82" | EF
| width="67" | 239
| width="288" |
Mean temperature for depth 100 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 81
| width="67" | '''11011011'''
| width="82" | DB
| width="67" | 219
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 82
| width="67" | ''00100000''
| width="82" | 20
| width="67" | 32
| width="288" |
The bit map (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 83
| width="67" | ''000'''''00101'''
| width="82" | 5
| width="67" | 5
| width="288" |
Standard deviations to be delivered (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 45
| width="67" | '''0'''''1101010''
| width="82" | 65
| width="67" | 101
| width="288" |
SDev of temperature for depth 0 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 85
| width="67" | ''11110101''
| width="82" | F5
| width="67" | 245
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 86
| width="67" | '''11010101'''
| width="82" | D5
| width="67" | 213
| width="288" |
SDev of temperature for depth 10 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 87
| width="67" | '''1110101'''''1''
| width="82" | EB
| width="67" | 235
| width="288" |
SDev of temperature for depth 20 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 88
| width="67" | ''10101011''
| width="82" | AB
| width="67" | 171
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 89
| width="67" | ''110101'''''11'''
| width="82" | D7
| width="67" | 215
| width="288" |
SDev of temperature for depth 30 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 90
| width="67" | '''01010111'''
| width="82" | 57
| width="67" | 87
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 91
| width="67" | '''10101'''''110''
| width="82" | A7
| width="67" | 167
| width="288" |
SDev of temperature for depth 40 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 92
| width="67" | ''10101111''
| width="82" | AF
| width="67" | 175
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 93
| width="67" | ''0101'''''1101'''
| width="82" | 5D
| width="67" | 93
| width="288" |
SDev of temperature for depth 50 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 94
| width="67" | '''01011110'''
| width="82" | 5E
| width="67" | 94
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 95
| width="67" | '''101'''''11010''
| width="82" | BA
| width="67" | 186
| width="288" |
SDev of temperature for depth 60 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 96
| width="67" | ''10111101''
| width="82" | BD
| width="67" | 189
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 97
| width="67" | ''01'''''110101'''
| width="82" | 75
| width="67" | 117
| width="288" |
SDev of temperature for depth 70 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 98
| width="67" | '''01111010'''
| width="82" | 7A
| width="67" | 122
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 99
| width="67" | '''1'''''1101010''
| width="82" | EA
| width="67" | 234
| width="288" |
SDev of temperature for depth 80 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 100
| width="67" | ''11110101''
| width="82" | F5
| width="67" | 245
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 101
| width="67" | '''11010101'''
| width="82" | D5
| width="67" | 213
| width="288" |
SDev of temperature for depth 90 m (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 102
| width="67" | '''1110101'''''1''
| width="82" | EB
| width="67" | 235
| width="288" |
SDev of temperature for depth 100 m (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 103
| width="67" | ''10101011''
| width="82" | AB
| width="67" | 171
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 104
| width="67" | ''110101'''''00'''
| width="82" | D4
| width="67" | 212
| width="288" |
Zero fill to complete and even number of octets

|}

== Additional Resources ==

none

{{Content|short title=BUFR and Statistics|description=An example to show how to include first order statistics into a BUFR message.|author=Bob.Keeley|approval status=approved|approved by=Bob.keeley|subsection of=BUFR and GRIB Formats|expertise level=beginner|categories=Marine Data Management}}

BUFR Length of Local Descriptors

2012-03-05T14:00:28Z

Bob.keeley: moved BUFR Length of Local Descriptors to 13. BUFR Length of Local Descriptors: To provide for a correct ordering of documents in this section

BUFR Adding an Associated Field

2012-03-05T13:54:10Z

Bob.keeley: moved BUFR Adding an Associated Field to 12. BUFR Adding an Associated Field: To provide for a correct ordering of documents in this section

BUFR Changing References in a Sequence

2012-03-05T13:47:18Z

Bob.keeley: moved BUFR Changing References in a Sequence to 11. BUFR Changing References in a Sequence: To provide for a correct ordering of documents in this section

BUFR Changing Widths, Scales and References

2012-03-05T13:40:41Z

Bob.keeley: moved BUFR Changing Widths, Scales and References to 10. BUFR Changing Widths, Scales and References: To provide for a correct ordering of documents in this section

BUFR Data Compression

2012-03-05T13:33:19Z

Bob.keeley: moved 9. BUFR Data Compression to 09. BUFR Data Compression: To provide for a correct ordering of documents in this section

BUFR Delayed Repetition

2012-03-05T13:25:43Z

Bob.keeley: moved 8. BUFR Delayed Repetition to 08. BUFR Delayed Repetition: To provide for a correct ordering of documents in this section

BUFR Delayed Replication Operator with Sequence

2012-03-05T13:18:50Z

Bob.keeley: moved 7. BUFR Delayed Replication Operator with Sequence to 07. BUFR Delayed Replication Operator with Sequence: To provide for a correct ordering of documents in this section

BUFR Delayed Replication Operator

2012-03-05T13:11:37Z

Bob.keeley: moved 6. BUFR Delayed Replication Operator to 06. BUFR Delayed Replication Operator: To provide for a correct ordering of documents in this section

BUFR Replication Operator

2012-03-05T13:03:20Z

Bob.keeley: moved 5. BUFR Replication Operator to 05. BUFR Replication Operator: To provide for a correct ordering of documents in this section

BUFR Optional Section

2012-03-05T12:53:57Z

Bob.keeley: moved 4. BUFR Optional Section to 04. BUFR Optional Section: To provide for a correct ordering of documents in this section

BUFR SYNOP

2012-03-05T11:25:58Z

Bob.keeley: moved 3. BUFR SYNOP to 03. BUFR SYNOP: To provide for a correct ordering of documents in this section

{{ContentHeader}}

Refer to the “Layer 1 and Layer 2” [http://www.wmo.int/pages/prog/www/WMOCodes/Guides/BUFRCREXPreface_en.html document] at WMO, section 2.2.1.2.

= Sample Content =

Consider a surface (weather) observation that appears in a SYNOP form (WMO FM 12-IX Ext. SYNOP). To transcribe this content into BUFR, it is convenient to utilize BUFR Table D sequence descriptor 3 07 002. The expansion of 3 07 002 is shown here along with some sample values and how these values appear in binary in a BUFR encoding.

This table illustrates how Table D descriptors expand to Table B descriptors. It also shows some sample values for a few of the descriptors used at the beginning and end of section 4 to illustrate how these are encoded into the BUFR example shown below. Note that the sequence 3 07 002 is composed of other sequences as well as simple descriptors and that this is true for embedded sequences as well. This illustrates how sequences for blocks of variables that frequently occur together can be used as building blocks to compose an entire BUFR message.

{| border="1" cellpadding="4" cellspacing="0" width="664"
|- valign="TOP"
| width="51" | FXY
| width="56" | FXY
| width="58" | FXY
| width="52" | FXY
| width="92" | Meaning
| width="32" | Bits
| width="61" | Value (decimal)
| width="42" | Raw value
| width="111" | Binary
| width="28" | Note
|- valign="TOP"
| rowspan="31" width="51" | 3 07 002
| rowspan="11" width="56" | 3 01 032
| rowspan="2" width="58" | 3 01 001
| width="52" | 0 01 001
| width="92" | WMO Block No.
| width="32" | 7
| width="61" | 4
| width="42" | 4
| width="111" | 0000100
| width="28" | 
|- valign="TOP"
| width="52" | 0 01 002
| width="92" | WMO Station No.
| width="32" | 10
| width="61" | 125
| width="42" | 125
| width="111" | 0001111101
| width="28" | 
|- valign="TOP"
| width="58" | 0 02 001
| width="52" | 
| width="92" | Type of station
| width="32" | 2
| width="61" | 0
| width="42" | 0
| width="111" | 00
| width="28" | 
|- valign="TOP"
| rowspan="3" width="58" | 3 01 011
| width="52" | 0 04 001
| width="92" | Year
| width="32" | 12
| width="61" | 2009
| width="42" | 2009
| width="111" | 011111011001
| width="28" | 
|- valign="TOP"
| width="52" | 0 04 002
| width="92" | Month
| width="32" | 4
| width="61" | 7
| width="42" | 7
| width="111" | 0111
| width="28" | 
|- valign="TOP"
| width="52" | 0 04 003
| width="92" | Day
| width="32" | 6
| width="61" | 23
| width="42" | 23
| width="111" | 010111
| width="28" | 
|- valign="TOP"
| rowspan="2" width="58" | 3 01 012
| width="52" | 0 04 004
| width="92" | Hour
| width="32" | 5
| width="61" | 15
| width="42" | 15
| width="111" | 01111
| width="28" | 
|- valign="TOP"
| width="52" | 0 04 005
| width="92" | Minute
| width="32" | 6
| width="61" | 6
| width="42" | 6
| width="111" | 000110
| width="28" | 
|- valign="TOP"
| rowspan="3" width="58" | 3 01 024
| width="52" | 0 05 002
| width="92" | Latitude (coarse)
| width="32" | 15
| width="61" | 46.75 N
| width="42" | 13675
| width="111" | 011010101101011
| width="28" | 1
|- valign="TOP"
| width="52" | 0 06 002
| width="92" | Longitude (coarse)
| width="32" | 16
| width="61" | 62.89 W
| width="42" | 11711
| width="111" | 0010110110111111
| width="28" | 2
|- valign="TOP"
| width="52" | 0 07 001
| width="92" | Height of station
| width="32" | 15
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 3
|- valign="TOP"
| rowspan="20" width="56" | 3 02 011
| rowspan="4" width="58" | 3 02 001
| width="52" | 0 10 004
| width="92" | Pressure
| width="32" | 14
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 10 051
| width="92" | Pressure reduced to MSL
| width="32" | 14
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 10 061
| width="92" | 3 hr pressure change
| width="32" | 10
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 10 063
| width="92" | Characteristic of pressure
| width="32" | 4
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| rowspan="9" width="58" | 3 02 003
| width="52" | 0 11 011
| width="92" | Wind direction
| width="32" | 9
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 11 012
| width="92" | Wind speed at 10m
| width="32" | 12
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 12 004
| width="92" | Dry bulb at 2m
| width="32" | 12
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 12 006
| width="92" | Dew point temp at 2m
| width="32" | 12
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 13 003
| width="92" | Relative humidity
| width="32" | 7
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 001
| width="92" | Horizontal visibility
| width="32" | 13
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 003
| width="92" | Present weather
| width="32" | 8
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 004
| width="92" | Past weather (1)
| width="32" | 4
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 005
| width="92" | Past weather (2)
| width="32" | 4
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| rowspan="7" width="58" | 3 02 004
| width="52" | 0 20 010
| width="92" | Cloud cover (total)
| width="32" | 7
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 08 002
| width="92" | Vertical significance surface obs
| width="32" | 6
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 011
| width="92" | Cloud amount
| width="32" | 4
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 013
| width="92" | Height of base of cloud
| width="32" | 11
| width="61" | 
| width="42" | 
| width="111" | 
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 012
| width="92" | Cloud type C1
| width="32" | 6
| width="61" | 8
| width="42" | 
| width="111" | 001000
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 012
| width="92" | Cloud type C2
| width="32" | 6
| width="61" | 1
| width="42" | 
| width="111" | 000001
| width="28" | 
|- valign="TOP"
| width="52" | 0 20 012
| width="92" | Cloud type C3
| width="32" | 6
| width="61" | 7
| width="42" | 
| width="111" | 000111
| width="28" | 
|}

Notes:

#Coarse latitude has a scale value of 2 therefore the 2 decimals are promoted to whole numbers (46.75 == 4675) and then the reference value is subtracted from the value (4675- (-9000) = 13675).
#Coarse longitude has a scale value of 2 therefore the 2 decimals are promoted to whole numbers (62.89 == 6289). Because the longitudes are all measured east of Greenwich, this must change to -6289. Then the reference value is subtracted from the value (-6289- (-18000) = 11711).
#Sample values from this point to the “height of base of cloud” are not required for the illustration here.

== BUFR Encoding ==

Section 0

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="48" | '''Section'''
| width="63" | '''Octet No.'''
| width="67" | '''Binary'''
| width="82" | '''Hexadecimal'''
| width="67" | '''Decoded'''
| width="288" |
'''Description / Comment'''

|- valign="TOP"
| width="48" | 0
| width="63" | 1
| width="67" | 01000010
| width="82" | 42
| width="67" | B
| width="288" |
Encoded using CCITT International Alphabet Number 5

|- valign="TOP"
| width="48" | 0
| width="63" | 2
| width="67" | 01010101
| width="82" | 55
| width="67" | U
| width="288" |
Encoded using CCITT International Alphabet Number 5

|- valign="TOP"
| width="48" | 0
| width="63" | 3
| width="67" | 01000110
| width="82" | 46
| width="67" | F
| width="288" |
Encoded using CCITT International Alphabet Number 5

|- valign="TOP"
| width="48" | 0
| width="63" | 4
| width="67" | 01010010
| width="82" | 52
| width="67" | R
| width="288" |
Encoded using CCITT International Alphabet Number 5

|- valign="TOP"
| width="48" | 0
| width="63" | 5
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="3" width="288" |
Length of section (octets)

|- valign="TOP"
| width="48" | 0
| width="63" | 6
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
|- valign="TOP"
| width="48" | 0
| width="63" | 7
| width="67" | 01001110
| width="82" | 4E
| width="67" | 78
|- valign="TOP"
| width="48" | 0
| width="63" | 8
| width="67" | 00000011
| width="82" | 3
| width="67" | 3
| width="288" |
BUFR edition number

|}

Section 1

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="48" | '''Section'''
| width="63" | '''Octet No.'''
| width="67" | '''Binary'''
| width="82" | '''Hexadecimal'''
| width="67" | '''Decoded'''
| width="288" |
'''Description / Comment'''

|- valign="TOP"
| width="48" | 1
| width="63" | 1
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="3" width="288" |
Length of section (octets)

(binary value of length coded over 24 bits)

|- valign="TOP"
| width="48" | 1
| width="63" | 2
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
|- valign="TOP"
| width="48" | 1
| width="63" | 3
| width="67" | 00010010
| width="82" | 12
| width="67" | 18
|- valign="TOP"
| width="48" | 1
| width="63" | 4
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="3" width="288" |
Originating centre (Code table 0 01 033; here 58 = U.S.Navy - FNOC)

|- valign="TOP"
| width="48" | 1
| width="63" | 5
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
|- valign="TOP"
| width="48" | 1
| width="63" | 6
| width="67" | 00111010
| width="82" | 3A
| width="67" | 58
|- valign="TOP"
| width="48" | 1
| width="63" | 7
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Update sequence number (here 0 for original data)

|- valign="TOP"
| width="48" | 1
| width="63" | 8
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Indicator that section 2 not included

|- valign="TOP"
| width="48" | 1
| width="63" | 9
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Table A – Data Category (here 0=surface land data)

|- valign="TOP"
| width="48" | 1
| width="63" | 10
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
BUFR message sub-type

|- valign="TOP"
| width="48" | 1
| width="63" | 11
| width="67" | 00001001
| width="82" | 9
| width="67" | 9
| width="288" |
Version number of master table

|- valign="TOP"
| width="48" | 1
| width="63" | 12
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Version number of local tables

|- valign="TOP"
| width="48" | 1
| width="63" | 13
| width="67" | 00001001
| width="82" | 9
| width="67" | 9
| width="288" |
Year of century (see note 1 below)

|- valign="TOP"
| width="48" | 1
| width="63" | 14
| width="67" | 00000100
| width="82" | 4
| width="67" | 4
| width="288" |
Month

|- valign="TOP"
| width="48" | 1
| width="63" | 15
| width="67" | 00010010
| width="82" | 12
| width="67" | 18
| width="288" |
Day

|- valign="TOP"
| width="48" | 1
| width="63" | 16
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Hour

|- valign="TOP"
| width="48" | 1
| width="63" | 17
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Minute

|- valign="TOP"
| width="48" | 1
| width="63" | 18
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Reserved for local use by ADP centres )also needed to complete even number of octets for the section)

|}

Note:

#The year of century is a compressed way to indicate the year of the message. The Layer 3 document (section 3.1.1.3) describes that the entry here should be the value of the year – 2000. So since the data here are from 2009, the entry in this octet is the value 9.

Section 2 is optional and has been omitted in this example.

Section 3

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="48" | '''Section'''
| width="63" | '''Octet No.'''
| width="67" | '''Binary'''
| width="82" | '''Hexadecimal'''
| width="67" | '''Decoded'''
| width="288" |
'''Description / Comment'''

|- valign="TOP"
| width="48" | 3
| width="63" | 1
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="3" width="288" |
Length of section (octets)

|- valign="TOP"
| width="48" | 3
| width="63" | 2
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
|- valign="TOP"
| width="48" | 3
| width="63" | 3
| width="67" | 00001010
| width="82" | 0A
| width="67" | 10
|- valign="TOP"
| width="48" | 3
| width="63" | 4
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Reserved

|- valign="TOP"
| width="48" | 3
| width="63" | 5
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="2" width="288" |
Number of data subsets (here 1 for 1 observation coded in the BUFR report in Section 4)

|- valign="TOP"
| width="48" | 3
| width="63" | 6
| width="67" | 00000001
| width="82" | 1
| width="67" | 1
|- valign="TOP"
| width="48" | 3
| width="63" | 7
| width="67" | 00000001
| width="82" | 1
| width="67" | 1
| width="288" |
Flag indicating observed data

|- valign="TOP"
| width="48" | 3
| width="63" | 8
| width="67" | 11000111
| width="82" | C7
| width="67" | 3 07
| rowspan="2" width="288" |
Table D descriptor for surface land in [F X Y] format. First octet is encoded as 2 (F) and 6 (X) bits: value of first 2 bits=3, value of next 6 bits=07

Second octet provides the value of the Y part of the descriptor. (here Y=002)

|- valign="TOP"
| width="48" | 3
| width="63" | 9
| width="67" | 00000010
| width="82" | 2
| width="67" | 002
|- valign="TOP"
| width="48" | 3
| width="63" | 10
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Zero filled to provide an even number of octets for section 3.

|}

Section 4

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="48" | '''Section'''
| width="63" | '''Octet No.'''
| width="67" | '''Binary'''
| width="82" | '''Hexadecimal'''
| width="67" | '''Decoded'''
| width="288" |
'''Description / Comment'''

|- valign="TOP"
| width="48" | 4
| width="63" | 1
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| rowspan="3" width="288" |
Length of section (octets)

|- valign="TOP"
| width="48" | 4
| width="63" | 2
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
|- valign="TOP"
| width="48" | 4
| width="63" | 3
| width="67" | 00100110
| width="82" | 26
| width="67" | 38
|- valign="TOP"
| width="48" | 4
| width="63" | 4
| width="67" | 00000000
| width="82" | 0
| width="67" | 0
| width="288" |
Reserved

|- valign="TOP"
| width="48" | 4
| width="63" | 5
| width="67" | '''0000100'''''0''
| width="82" | 8
| width="67" | 4
| width="288" |
WMO block number (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 6
| width="67" | ''00111110''
| width="82" | 3E
| width="67" | 62
| width="288" |
WMO station number (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 7
| width="67" | ''1'''''00'''''01111''
| width="82" | 8F
| width="67" | 143
| width="288" |
Type of station (bold), followed by Year (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 8
| width="67" | ''1011001'''''0'''
| width="82" | B2
| width="67" | 178
| width="288" |
Month (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 9
| width="67" | '''111'''''01011''
| width="82" | EB
| width="67" | 235
| width="288" |
Day (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 10
| width="67" | ''1'''''01111'''''00''
| width="82" | BC
| width="67" | 188
| width="288" |
Hour (bold), followed by Minute (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 11
| width="67" | ''0110'''0110'''''
| width="82" | 66
| width="67" | 102
| width="288" |
Latitude (bold)

|- valign="TOP"
| width="48" | 4
| width="63" | 12
| width="67" | '''10101101'''
| width="82" | AD
| width="67" | 173
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 13
| width="67" | '''011'''''00101''
| width="82" | 65
| width="67" | 101
| width="288" |
Longitude (italic)

|- valign="TOP"
| width="48" | 4
| width="63" | 14
| width="67" | ''10110111''
| width="82" | B7
| width="67" | 183
| width="288" |

|- valign="TOP"
| width="48" | 4
| width="63" | 15
| width="67" | ''111''.....
| width="82" | 
| width="67" | 
| rowspan="2" width="288" |
The rest of the data follows

|- valign="TOP"
| width="48" | 4
| width="63" | 16-37
| width="67" | 
| width="82" | 
| width="67" | 
|- valign="TOP"
| width="48" | 4
| width="63" | 38
| width="67" | 
| width="82" | 
| width="67" | 
| width="288" |
End of bit stream

|}

Section 5

{| border="1" cellpadding="4" cellspacing="0" width="665"
|- valign="TOP"
| width="48" | '''Section'''
| width="63" | '''Octet No.'''
| width="67" | '''Binary'''
| width="82" | '''Hexadecimal'''
| width="67" | '''Decoded'''
| width="288" |
'''Description / Comment'''

|- valign="TOP"
| width="48" | 5
| width="63" | 1
| width="67" | 00110111
| width="82" | 37
| width="67" | 7
| width="288" |
Encoded using CCITT International Alphabet Number 5

|- valign="TOP"
| width="48" | 5
| width="63" | 2
| width="67" | 00110111
| width="82" | 37
| width="67" | 7
| width="288" |
Encoded using CCITT International Alphabet Number 5

|- valign="TOP"
| width="48" | 5
| width="63" | 3
| width="67" | 00110111
| width="82" | 37
| width="67" | 7
| width="288" |
Encoded using CCITT International Alphabet Number 5

|- valign="TOP"
| width="48" | 5
| width="63" | 4
| width="67" | 00110111
| width="82" | 37
| width="67" | 7
| width="288" |
Encoded using CCITT International Alphabet Number 5

|}

== ]Additional Resources ==

none

{{Content|short title=BUFR SYNOP|description=An example of how the content of a SYNOP message is encoded into BUFR.|author=Bob.Keeley|approval status=approved|approved by=Bob.keeley|subsection of=BUFR and GRIB Formats|expertise level=beginner|categories=Marine Data Management}}

BUFR Sections 0 and 5

2012-03-05T11:09:10Z

Bob.keeley: moved 2. BUFR Sections 0 and 5 to 02. BUFR Sections 0 and 5: To provide for a correct ordering of documents in this section

Introduction to BUFR Exercises

2012-03-05T09:54:50Z

Bob.keeley: moved 1. Introduction to BUFR Exercises to 01. Introduction to BUFR Exercises: To provide for a correct ordering of documents in this section

{{ContentHeader}}

== Introduction ==

The exercises that are part of this subsection were built to illustrate examples that are found in two documents that are available from WMO. These are called “Layer 1 and Layer 2” and “Layer 3”. There is much useful, introductory material in these documents. Those contemplating using these exercises and recommended to read the WMO documents at least up to the sections where examples begin. It is also advised that the exercises progress from simple ones to more complex ones and that what is learned in the simpler ones sometimes is used in the later, more complex ones.

Before proceeding to the exercises, we reproduce here in brief some material from WMO documents.

== Code Structure ==

The structures of the BUFR code form is the following:

SECTION 0 Indicator Section

SECTION 1 Identification Section

SECTION 2 (Optional Section)

SECTION 3 Data Description Section

SECTION 4 Data Section

SECTION 5 End Section

The Indicator Sections and the BUFR Identification Section are short sections, which identify the message. The list of descriptors, pointing towards elements in predefined and internationally agreed tables that are stored in the official WMO Manual on Codes (described previously), are contained in the Data Description Section. These descriptors describe the type of data contained in the Data Section and the order in which the data appear there. The Optional Section can be used to transmit any information or parameters for national purpose. The End Section contains the four alphanumeric characters "7777" to denote the end of the BUFR message.

==  BUFR Tables ==

Tables define how the parameters (or elements) shall be coded as data items in a BUFR message (i.e. units, size, scale). They are recorded in the [http://www.wmo.int/pages/prog/www/WMOCodes.html WMO Manual on Codes], Volume I.2 (International Codes), Parts B (Binary Codes) and C (Common Features to Binary and Alphanumeric Codes). The Manual on Codes also comprises Volume I.1 (international Codes), Part A (Alphanumeric Codes) and Volume II: Regional Codes and National Coding Practices. These three volumes are collectively referred to as WMO Publication No. 306. The Tables defining BUFR coding are Tables A, B, C, and D.

Table A subdivides data into a number of discrete categories (e.g. Surface data – land, Surface data - sea, Vertical soundings (other than satellite), Vertical soundings (satellite), etc.). While not technically essential for BUFR encoding/decoding systems, the data categories in Table A are useful for telecommunications purposes and for storage of data in and retrieval of data from a data base.

Table B describes how individual parameters, or elements, are to be encoded and decoded in BUFR. For each element, the table lists the reference number (or element descriptor number, which is used in the description section of the code like a "pointer", as explained earlier), the element name, and the information needed to encode or decode the element. This information consists of the units to be used, scale and reference values to apply to the element, and the number of bits used to describe the value of the element (the BUFR data width). The data items transmitted in a report will have their descriptor numbers listed in the Data Description Section.

Table B is fundamental to encoding and decoding in both BUFR and CREX.

Table C defines a number of operations that can be applied to the elements. Each such operation is assigned an operator descriptor. For example, it contains operator descriptors to change the scale value, the reference value, or data width listed for a parameter in BUFR Table B. Some of the operations defined in BUFR Table C are quite complex. Operator descriptors are described in Layer 2 and at length in Layer 3.

Operator descriptors, although not essential for BUFR encoding and decoding, are useful in minimizing the number of new table entries and including quality assessment information.

Table D defines groups of elements that are always transmitted together (like a regular SYNOP or TEMP report) in what is called a common sequence. By using a common sequence descriptor, the individual element descriptors will not need to be listed each time in the data description section. This will reduce the amount of space required for a BUFR message. Common sequences are defined in BUFR Tables D.

Sequence descriptors, although not essential for BUFR encoding and decoding, are useful in decreasing the space requirements for BUFR messages.

BUFR also makes use of Code and Flag Tables. An element based on a code (e.g., Cloud Type) or a set of conditions defined by flags (bits set to 0 or 1) will have an associated Code Table or Flag Table. In this case, "Code Table" or "Flag Table" will appear in the Unit column of Table B.

== Introduction to Exercises ==

BUFR is not a simple format to construct, nor an easy one to read. Because it is in binary, a computer is needed to be able efficiently to read or write the format. Most computers these days have 32 bit words made up of 4 – 8 bit bytes (these are called octets in BUFR terminology). BUFR writes information into these bytes using only as many bits as required. So, a variable requiring only 7 bits uses only 7, with the next item in the BUFR message starting immediately after in the 8th bit. Thus, BUFR data crosses both byte and word boundaries in computers. Different computer manufacturers have a different ordering of filling bits in words (computers are termed big-endian or little-endian using a Lewis Carol reference) and BUFR software must take this into consideration so that on every machine that reads and writes BUFR, bits are filled continuously from left to right in a word.

The exercises have been adapted to illustrate ocean data and so show differences from the examples found in these documents. The exercises are very detailed to illustrate exactly how the data are encoded into BUFR. Exercises are presented separately in the same order as shown in the WMO documents. Each references the appropriate WMO document and its subsection. Some text from the WMO documents are used in introductions to exercises.

The list of examples is as follows:

#Section 0 and Section 5 of BUFR
#Example SYNOP
#Use of the optional section
#Use of the simple replication operator
#Use of the delayed replication operator
#Use of the delayed replication operator with a sequence
#Delayed repetition
#Data compression
#Changing data width, scales, and reference values
#Changing the reference value when embedded in a sequence
#Add an associated field – including quality information
#Signifying length of local descriptors
#First order statistics
#Quality information and replaced values

== Additional Resources ==

none

{{Content|short title=Introduction|description=An introduction to exercises illustrating how ocean data are written into BUFR|author=Bob.Keeley|approval status=approved|approved by=Bob.keeley|subsection of=BUFR and GRIB Formats|expertise level=beginner|categories=Marine Data Management}}

Data from Tagged Biota

2012-02-10T15:39:59Z

Bob.keeley:

{{ContentHeader}}

== Background ==

In the last few years, instrumentation and telecommunications technology have developed such that it has become feasible to attach tracking tags as well as sensors to animals that spend their lives at sea. Examples of these programmes include the Tagging of Pacific Predators ([http://www.montereybayaquarium.org/cr/topp.aspx TOPP]) and the [http://oceantrackingnetwork.org/ Ocean Tracking Network]. The main thrust of these programmes is to monitor the positions and movements of animals. They both use technology that does not yet monitor ocean conditions and is not amenable to reporting information in real-time. An [http://www.oceanobs09.net/proceedings/cwp/cwp66/index.php OceanObs'09 Community White Paper] on the Ocean Tracking Network provides details on this programme and [http://www.oceanobs09.net/proceedings/cwp/cwp19/index.php another] explains the TOPP programme. Because there is no ability to report in real-time, no further information will be provided here.

There is another programme, co-ordinated by the University of St. Andrews' Sea Mammal Research Unit ([http://www.smru.st-and.ac.uk/default.aspx SMRU]). This programme attaches CTD (conductivity/salinity, temperature and depth) recorders to larger mammals. These last typically last up to a year before falling off or the battery fails. The CTDs record temperature and salinity as the animal dives, and upon surfacing these data are transmitted through satellite to shore. There were two Community White Papers presented at OceanObs'09 on this programme. One described the [http://www.oceanobs09.net/proceedings/cwp/cwp06/index.php programme], and the other described some of the [http://www.oceanobs09.net/proceedings/cwp/cwp15/index.php results].

There are many countries that employ these sorts of tags, but the initial processing of data returned is carried out by SMRU. Anyone considering using such technology, should consult with them. It is also worthwhile to talk to the [http://wo.jcommops.org/cgi-bin/WebObjects/JCOMMOPS JCOMMOPS]office for help getting started.

== Step 1: Getting data ashore ==

Researchers who wish to participate in the activities co-ordinated by SMRU are not required to release their data in real-time. However, many have agreed to do so. The data collected in waters where the animals swim is especially important in monitoring the world ocean and in the development of operational ocean models and forecasting. These animals often swim in regions that are difficult for ships to operate in, or far from ports. Also, many times they are in regions close to sea ice which are hazardous to ship operations and automated instruments. All researchers deploying such instruments are encouraged to permit real-time release of their data. This simply requires appropriate notification to SMRU.

These instruments typically report through the facilities of [http://www.argos-system.org/web/en/83-international-programs.php#argo Service Argos]. The reporting is very similar to all other instruments handled by Service Argos. The difference is that researchers allow the raw data to be assembled by SMRU who then do the processing to reliably establish position information. The resulting data can then be provided directly to researchers. Researchers can choose to manage getting data to the Global Telecommunications System (GTS) by themselves, or if real-time distribution permission is given, SMRU will move the data to the GTS on their behalf.

== Step 2: Getting platform identifiers ==

Like all conventional platforms making measurements at sea and reporting in real-time, data coming from animals must have appropriate identifiers. A block of numbers has been assigned by the World Meteorological Organization (WMO) to the SMRU for use in this programme. Each animal is assigned a unique identifier (preceded by “Q99” as the identifier is seen on the GTS). When the reports from an animal cease, the number is retired, never to be used again.

If you choose to do this work on your own, speak to SMRU in any case to get advice on how to get identifiers.

== Step 3: Formating data for the GTS ==

After the data come ashore and have platform identifiers, they must be converted to the appropriate character code form (usually BATHY or TESAC) or into BUFR for distribution on the GTS. The simplest way to do this is to allow SMRU to take care of this process for you. In this they are supported by the British Oceanographic Data Centre ([http://www.bodc.ac.uk/ BODC]). The BODC takes the raw data provided by SMRU, converts them to appropriate formats and provides them to the U.K Meteorological Office for distribution on the GTS.

If you don't wish to use the services of SMRU, it may be that BODC can still assist. You may wish to contact them directly to ask.

If your country already has systems in place for formatting and delivering data to the GTS, your only task is to contact the people operating them. To identify them, it is simplest to contact the SOT technical Coordinator, or the [http://www.jcommops.org/SOT/contacts.html SOOP Chair]or speak to [http://www.wmo.int/pages/members/membership/nhs_en.html your country's national meteorological service.]Another avenue would be to talk to your [http://www.iode.org/index.php?option=com_oe&task=viewGroupRecord&groupID=59&Itemid=42 national co-ordinator]for oceanographic data, if you have one, or speak to [http://www.iode.org/ IODE]for assistance.

If you decide to format data yourself for the GTS, you are encouraged to have an independent organization verify that you have created your format correctly. Your meteorological service may be able to help, or you can contact BODC.

== Step 4: Quality Control ==

Data providers are encouraged to examine the data they collect and to remove the most egregious errors that are present. However, it is encouraged to be cautious in doing this since outliers may be real and to miss these will skew our perception of what is happening in the ocean. Users of GTS data are aware that very detailed quality control cannot take place before the data are distributed in real-time and they accept that they will need to carry out quality control procedures on the data that are distributed.

If SMRU is given permission to distribute the data on your behalf, they in conjunction with BODC will carry out some quality checks. These are the same as would be used for any lowered instrument data (see that document in the Digital Library).

If you decide to prepare the data yourself, you are encouraged to look at the Digital Library document “Lowered Instrument Data” and follow the links that point to quality control procedures.

== Additional Resources ==

GTS: [http://www.wmo.int/pages/prog/www/TEM/GTS/ManOnGTS_en.html http://www.wmo.int/pages/prog/www/TEM/GTS/ManOnGTS_en.html]

WMO: [http://www.wmo.int/pages/index_en.html http://www.wmo.int/pages/index_en.html]

{{Content|short title=Data from Tagged Biota|description=Step-by-step instructions for getting such data on the GTS.|author=bob.keeley|approval status=approved|approved by=bob.keeley|subsection of=Exchanging Ocean Data in Real-time|expertise level=beginner|categories=Marine Data Management}}

Towed Instruments and Underway Data

2012-02-10T15:34:23Z

Bob.keeley:

{{ContentHeader}}

== Background ==

Along track measurements such as those made with instruments that are towed from a ship, are captured through seawater sampling systems or made by deck mounted instruments may require a multi-step process to get the data distributed in real-time. There are a variety of instruments that collect idata in this mode. While this includes towed subsurface CTDs, cameras, as well as meterorological measurements from deck mounted systems, and thermosalinograph systems., there are no co-ordinated systems in place to deal with towed, subsurface CTD or camera systems and so they are not treated here.

Deck mounted meteorological systems measure a wide variety of variables with automated systems. The Shipboard Automated Meteorological and Oceanographic System ([http://samos.coaps.fsu.edu/html/ SAMOS]) started a number of years ago during the World Ocean Circulation Experiment. It was originally designed to manage data from research meteorological systems on U.S. research vessels. Over time, it has expanded to cover other U.S. vessels and now considers data from foreign vessels. A description of the program is also available as an [http://www.oceanobs09.net/proceedings/cwp/cwp82/index.php OceanObs'09 Community White Paper] as well as there being a description of the [http://www.oceanobs09.net/proceedings/cwp/cwp83/index.php data management system].

Underway measurements of ocean temperature and salinity have been made using the thermosalinograph. This is still true, but there are now additional sensors that can be used to measure other variables such as nutrients, fluorescence, and oxygen. The data from such measurements is coordinated by the Global Ocean Surface Underway Data ([http://www.gosud.org/ GOSUD]) Project. While temperature and salinity have been the focus, other variables associated with them are also handled. There is an OceanObs'09 Community White Paper dealing with surface measurements from “[http://www.oceanobs09.net/proceedings/cwp/cwp46/index.php ferry box systems]”.

There is also a well developed system for making and handling measurements from continuous plankton recorders. An [http://www.oceanobs09.net/proceedings/cwp/cwp73/index.php OceanObs'09 Community White Paper] provides a clear description of this programme. However, because this system does not analyze data within the time frames required for real-time distribution, no additional treatment is provided here.

This document deals only with oceanographic variables and so those interested in meteorological data should consult the various links provided above.

== Step 1: Getting platform identifiers ==

In order to report data on the GTS, the ship must use an identifier called a call sign. This is assigned to a ship by each country with due notification provided to the International Telecommunication Union (ITU). Each country has a member and this information is available from the ITU web site. They can help if you need to set the ship’s identification. Alternatively, and a more straightforward route, is to consult the [http://wo.jcommops.org/cgi-bin/WebObjects/JCOMMOPS SOT Technical Co-ordinator ]at JCOMMOPS (see “Contacts” in right hand menu).

== Step 2: Getting data ashore ==

The data gathered on board the platform need to be sent ashore. The ship can use the facilities promoted by the SOOP. To do so, contact either the [http://www.jcommops.org/SOT/contacts.html SOT Chair]or SOT Technical Coordinator.

Alternatively, countries may choose to get data ashore through other methods. For example, data collected by vessels will sometimes be sent ashore through email. Alternatively, for cruises of short duration (shorter than the 30 day cut off for ocean data on the GTS), the cruise operator may bring the data back to port before any preparation for dissemination occurs. Contact your [http://iode.org/index.php?option=com_oe&task=viewGroupRecord&groupID=59&Itemid=42 national co-ordinator ]for ocean data management or [http://iode.org/ IODE](select “contact us” in the left hand menu) for advice or assistance.

== Step 3: Formating data ==

After the data come ashore, they must be converted to the appropriate character code form (TRACKOB) or into BUFR for distribution on the GTS.

If your country already has systems in place for reporting ocean data in real-time, it may be that ocean surface underway data are handled already. It is recommended to consult [http://www.wmo.int/pages/members/membership/nhs_en.html your country's national meteorological service].

If such data are not handled within your country, you are advised to consult the [http://www.iode.org/index.php?option=com_content&view=article&id=20:underway-sea-surface-salinity-data-archiving-pilot-project-gosud&catid=14&Itemid=59 chair of GOSUD].

You may decide to take control of formatting the data for yourself. If so, the appropriate data formats for the GTS are generally described in the Digital Library document “Formats for Real-time Data Exchange”. This document also describes how to get the data to the GTS. At present both TRACKOB and BUFR can only handle measurements of temperature, salinity, and surface currents although newer templates for BUFR with wider reporting capability are being worked on. Talk to the [http://www.jcomm.info/index.php?option=com_oe&task=viewGroupRecord&groupID=117 chair of the Data Management Co-ordination Group] of JCOMM for more information. You can also consult the [http://www.gosud.org/Documentation GOSUD documentation]. If you choose this path, it is advised to contact the GOSUD programme so that someone there who is used to handling GTS formatted data can check your formatting before it is sent to the GTS.

== Step 4: Quality Control ==

Data providers are encouraged to examine the data they collect and to remove the most egregious errors that are present. However, it is encouraged to be cautious in doing this since outliers may be real and to miss these will skew our perception of what is happening in the ocean. Users of GTS data are aware that very detailed quality control cannot take place before the data are distributed in real-time and they accept that they will need to carry out quality control procedures on the data that are distributed. Data providers are urged to consult the GOSUD programme for references to quality control procedures employed by project participants.

== Additional Resources ==

GTS: [http://www.wmo.int/pages/prog/www/TEM/GTS/ManOnGTS_en.html http://www.wmo.int/pages/prog/www/TEM/GTS/ManOnGTS_en.html]

International Telecommunication Union: [http://www.itu.int/ http://www.itu.int/]

Ship Of Opportunity Programme (SOOP): [http://www.jcommops.org/soopip/ http://www.jcommops.org/soopip/]

World Ocean Circulation Experiment (WOCE): [http://www.nodc.noaa.gov/WOCE/ http://www.nodc.noaa.gov/WOCE/]

{{Content|short title=Underway Instrument Data|description=Step-by-step instructions for getting data from towed instruments on the GTS.|author=bob.keeley|approval status=approved|approved by=bob.keeley|subsection of=Exchanging Ocean Data in Real-time|expertise level=beginner|categories=Marine Data Management}}

Drifting Buoy Data

2012-02-10T15:27:39Z

Bob.keeley:

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== Background ==

An international drifting buoy programme had its origins in the First GARP (Global Atmospheric Research Programme) Global Experiment in 1987. Since then, considerable resources have been expended on the programme so that today there is a well co-ordinated program for exchanging data and information on manufacture, deployment, telecommunications and data management for drifting buoys. This is focused in the Data Buoy Co-operation Panel ([http://www.jcommops.org/dbcp/ DBCP]) of JCOMM. Anyone contemplating deploying drifting buoys should contact the [http://www.jcommops.org/dbcp/community/contacts.html chair]of the Panel or the [http://www.jcommops.org/dbcp/community/contacts.html DBCP Technical Co-ordinator.]

A number of nations also deploy drifting buoys for short term experiments or to assist in search and rescue operations. It is unusual for these data to reach the international system, but they can be a valuable adjunct if they were reported.

An description of the data management system for the drifting buoy programme is provided in an [http://www.oceanobs09.net/proceedings/cwp/cwp47/index.php OceanObs'09 Community White Paper].

== Step 1: Identifying the buoys ==

Before you can distribute data in real-time on the GTS, you must have a World Meteorological Organization (WMO)[http://www.wmo.int/pages/prog/amp/mmop/wmo-number-rules.html identifier]given to your buoy. The DBCP Technical Co-ordinator will be happy to assist in all aspects of deploying drifters.

The DBCP has designated [http://www.jcomm.info/index.php?option=com_oe&task=viewGroupRecord&groupID=147 national focal points ]to assist buoy operators. If you are planning to work with your national focal point, contact them well ahead of your deployment and request information on their submission guidelines. They may assist you in acquiring a WMO identifier for your buoy, provide guidance on which of your measurements are suitable for insertion onto the GTS, and help ensure that you follow conventions for these parameters. They will also be able to describe the data formats that they can accept, and provide you with a mechanism for submitting your data, usually in the form of an FTP server address and user account.

== Step 2: Getting data ashore ==

Using [http://www.argos-system.org/web/en/83-international-programs.php#argo Service Argos] is a common way for data ashore from drifters. Abuoy operator needs to provide sufficient information to explain how to extract the data from the message sent by the PTT. Service Argos then configures their decoder to read the data transmission from the buoy and to extract the observations made. The DBCP Technical Co-ordinator can help with this process, especially because they are located very near the Service Argos offices in France.

The [http://www.iridium.com/ Iridium] cell phone system is another way to get data ashore. The advantages of this is that there is greater bandwidth for at sea communications (though power requirements are higher). This allows sufficient bandwidth such that most if not all of the data can be transmitted in a single message to a receiver. Data are typically sent from the buoy to the operator’s shore-side processing centre using one of several Iridium modes, often Short Burst Messaging (SBD), which delivers data as an email attachment, to be processed locally, based on the contents of the payload.

There also may be facilities in your country for managing the telecommunications from drifters to shore. It is a good idea to talk to your national focal point to explore this possibility.

== Step 3: Distributing the data ==

When Service Argos manages the insertion of the data onto the GTS, their processing software extracts observations from the message transmitted from the drifter, reformats the data to appear on the GTS into both BUOY code (a character code form) and BUFR (the binary code form), and inserts the data onto the GTS.

Iridium service providers, with the exception of CLS ([http://www.clsamerica.com/ english]or [http://www.cls.fr/ french]), do not offer the option to forward data to the GTS automatically. For those who purchase Iridium service through CLS, obtain a form (GTS Technical File) which will provide sufficient information for CLS to extract the data from the Iridium message. Service Argos then configures their decoder to be able to read the data transmission from the buoy to extract the observations made, reformat the data to appear, and forwards the data to the GTS.

If another Iridium Service Provider (not Service Argos) or some other telecommunications system is used to get data ashore, the onus is on the buoy operator to prepare the data in the correct format and for insertion onto the GTS. As noted above, BUOY or BUFR encoding is required for the data. Details of this format are described in the digital library document “Formats for Real-time Data Exchange”.

Since National Meteorological Services are the only agencies with direct access to the GTS, you will need to contact [http://www.wmo.int/pages/members/membership/nhs_en.html your country's national meteorological service]to make arrangements to move the data from your agency to theirs. It is worthwhile to contact them as soon as possible since they may already have facilities in place that can assist you in getting the data formatted correctly for GTS distribution.

== Step 4: Quality control ==

The responsibility for basic quality control can be handled by the data provider or perhaps by an agency managing insertion of the data onto the GTS. Data providers should inquire if such services are available for them. Data providers are encouraged to remove the most egregious errors before the data are distributed. Data providers are strongly urged to examine information about DBCP recommended [http://www.jcommops.org/dbcp/data/qc.html quality control procedures].

== Additional Resources ==

FGGE: [http://unesdoc.unesco.org/images/0003/000348/034822eb.pdf http://unesdoc.unesco.org/images/0003/000348/034822eb.pdf]

GTS: [http://www.wmo.int/pages/prog/www/TEM/GTS/index_en.html http://www.wmo.int/pages/prog/www/TEM/GTS/index_en.html]

JCOMMOPS (for general information on ocean observing programmes): [http://www.jcommops.org/ www.jcommops.org/]

{{Content|short title=Drifting Buoy Data|description=This provides information about exchange of data acquired by drifting buoys.|author=bob.keeley|approval status=approved|approved by=bob.keeley|subsection of=Exchanging Ocean Data in Real-time|expertise level=beginner|categories=Marine Data Management}}

Moored Buoy Data

2012-02-10T15:14:19Z

Bob.keeley:

{{ContentHeader}}

== Background ==

National weather agencies and diverse research programs maintain moored buoys for different periods of time to collect marine meteorological and sometimes oceanographic data. Examples include the equatorial moorings in Pacific, Atlantic, and Indian Oceans managed by the Tropical moored buoy Implementation Panel ([http://www.pmel.noaa.gov/tao/proj_over/tip/newpanel.html TIP]). Buoys, whether moored or drifting, are overviewed by the Data Buoy Co-operation Panel ([http://www.jcommops.org/dbcp/ DBCP]) of JCOMM.

A number of nations also maintain networks of coastal buoys that gather data at high frequency. Often these are maintained and operated by national weather agencies. Generally, all of the data are made available in real-time. Ocean research programs also deploy moored platforms and in most cases these, too, record meteorological information as well as oceanographic measurements. It is not the case that all of these data get to national agencies and are distributed in real-time.

An overview of the tropical moored buoy programme is described in an [http://www.oceanobs09.net/proceedings/cwp/cwp61/index.php OceanObs'09 Community White Paper.]

An international programme for deep ocean moorings, [http://www.oceansites.org/ OceanSITES], has begun recently. OceanSITES is a worldwide system of long-term, deepwater reference stations measuring dozens of variables and monitoring the full depth of the ocean from air-sea interactions down to 5,000 meters. Not all of the variables in the complete suite have a place in present real-time data exchange formats. An [http://www.oceanobs09.net/proceedings/cwp/cwp79/index.php OceanObs'09 Community White paper] describes this programme.

== Using National Focal Points ==

=== Step 1: Identifying the buoys ===

The DBCP has designated [http://www.jcomm.info/index.php?option=com_oe&task=viewGroupRecord&groupID=147 national focal points ]to assist buoy operators. If you are planning to work with your national focal point, contact them well ahead of your deployment and request information on their submission guidelines. They may assist you in acquiring a WMO identifier for your buoy, provide guidance on which of your measurements are suitable for insertion onto the GTS, and help ensure that you follow conventions for these parameters. They will also be able to describe the data formats that they can accept, and provide you with a mechanism for submitting your data, usually in the form of an FTP server address and user account.

=== Step 2: Preparing data ===

The national focal point will request information about your data sources that will help ensure that it is used appropriately. Important metadata includes the instrumentation used, descriptions of how the instruments were deployed, the names of the measured variables, the units of measurement, the precision and accuracy of the measurements, their complete location (both horizontal and vertical dimensions), the relationship between the time value and the sample period of each parameter, details of any processing such as averaging, calibration, etc. that may have occurred, and so on. Any information that would be needed by someone else to correctly use the data should be provided.

===  Step 3: Formatting the data ===

The format and mechanism for data transport will be established with your national agency. Different national focal point agencies may have their own allowed formats for incoming data. For example, the [http://www.ndbc.noaa.gov/ NDBC], accepts data in BUFR and in two alternative formats. It also provides software to assist users in creating compliant files.

=== Step 4: Distributing the data ===

Once the data provider begins sending data to the national focal point, the data should be monitored to ensure that any errors are found and corrected if possible. Any change in location of a moored buoy should also be reported immediately. If the national focal point is providing quality control services, they may inform the data provider of any problems seen; the data provider should likewise notify the national focal point if problems are detected, if the buoy position changes, if instruments are replaced or if service interruptions are expected.

== Not using National Focal Points ==

If you do not have a national focal point or wish to handle data operations yourself, you will need to follow the following steps.

=== Step 1: Identifying the buoys ===

The DBCP is an important resource for anyone contemplating deployment of a moored platform. Visit the DBCP web site or contact the [http://www.jcommops.org/dbcp/community/contacts.html DBCP Technical Co-ordinator] for advice.

Before your moored buoy can report data in real-time it needs to be assigned a unique World Meteorological Organization (WMO) identifier. Each country has been assigned a block of numbers for its use and the country's [http://www.jcomm.info/index.php?option=com_oe&task=viewGroupRecord&groupID=147 national focal point] can provide identifiers for you. If your country has never deployed moored buoys before or never reported such data in real-time, contact the DBCP Technical Co-ordinator.

=== Step 2 Getting data ashore via Service Argos ===

Use of the [http://www.argos-system.org/web/en/83-international-programs.php#argo Service Argos] system is one of the ways that data are transmitted from buoys to shore. If you are interested in learning more, contact Service Argos directly, or talk to the DBCP Technical Co-ordinator.

=== Step 3: Distributing data via Service Argos ===

When Service Argos manages the insertion of the data onto the GTS, a buoy operator needs to provide sufficient information to tell them how to extract the data from the message sent by the PTT. Service Argos then configures their decoder to be able to read the data transmission from the buoy to extract the observations made, reformat the data to appear on the GTS in both BUOY code (a character code form) and BUFR (the binary code form). Information on GTS formats is available in the document “Formats for real-time Data Exchange”.

=== Step 2: Getting data ashore using the Iridium system ===

The [http://www.iridium.com/ Iridium] cell phone system is another way to get data ashore. The advantages of this is that there is greater bandwidth for at sea communications (though power requirements are higher). This allows sufficient bandwidth such that most if not all of the data can be transmitted in a single message to a receiver.

Data are typically sent from the buoy to the operator’s shore-side processing center using one of several Iridium modes, often Short Burst Messaging (SBD), which delivers data as an email attachment, to be processed locally, based on the contents of the payload. The operator adds a step to the local processing system to create a file with new data to be sent via ftp to the national focal point.

=== Step 3: Distributing data when using the Iridium system ===

Iridium service providers, with the exception of CLS ([http://www.clsamerica.com/ english] or [http://www.cls.fr/ french]), do not offer the option to forward data to the GTS automatically. For those who purchase Iridium service through CLS, obtain a form (GTS Technical File) which will provide sufficient information for CLS to extract the data from the Iridium message. Service Argos then configures their decoder to be able to read the data transmission from the buoy to extract the observations made, reformat the data to appear on the GTS.

For those using other Iridium service providers, it is possible to make arrangements with your country’s DBCP National Focal Point to submit the data for you. As example for the US, this is the National Data Buoy Center ([http://www.ndbc.noaa.gov/ NDBC]).

== Other Means ==

If neither Service Argos or the Iridium system meet your requirements, you will need to find another way to get data from the buoy to your shore-side processing facility, to prepare the data for real-time distribution and upload to the GTS. You are advised to consult the DBCP technical co-ordinator to discuss your issues. Also, you will need to contact your national meteorological service which is your gateway to the GTS. As well, they may be aware of other moored buoy operators in your country, outside of your knowledge, and can help you get in contact with them.

== Step 4: Quality control ==

The responsibility for basic quality control can be handled by the data provider or by the national focal point. Data providers are encouraged to remove the most egregious errors before the data are distributed. Data providers are strongly urged to examine information about DBCP recommended [http://www.jcommops.org/dbcp/data/qc.html quality control procedures].

== Additional Resources ==

GTS: [http://www.wmo.int/pages/prog/www/TEM/GTS/index_en.html http://www.wmo.int/pages/prog/www/TEM/GTS/index_en.html]

JCOMMOPS (for general information on ocean observing programmes): [http://www.jcommops.org/ www.jcommops.org/]

{{Content|short title=Moored Buoy Data|description=This provides information about exchange of data acquired by moored buoys.|author=bob.keeley|approval status=approved|approved by=bob.keeley|subsection of=Exchanging Ocean Data in Real-time|expertise level=beginner|categories=Marine Data Management}}