Dataset Format Description

 

NESDIS SST Temporary Observation File

 

This file contains retrievals or observations in a format which can be readily sorted according to 100km field row and column or 5 degree and 1 degree square.

 

This file is a sequential data set with fixed-length data records.  The data record length is 104 bytes.  Since no HIRS data are included in the retrievals, bytes 65 through 104 in each data record are padded with zeroes.

 

Following normal convention, the first (most significant) bit in the byte sequence for each value is the sign bit (0-positive, 1-negative).

 

Below are the contents of each data record in this file.

 

BYTE(S)

VALUE

UNITS

NOTE

1-2

5 degree Square #                

Numeric

Range is 1 to 2592.

3-4

1 degree Square #                 

Numeric

Range is 1 to 25.

5-6

Row # of nearest 100km field point (row -6 is 77S & incr. by 1 each degree northward)

Numeric

Range is -6 to 151 (77S to 80N).

7-8

Column of nearest 100km field point (row 1 is 179W & incr. by 1 each degree eastward)

Numeric

Range is 1 to 360.

9

Type of SST observation/retrieval

Numeric

See local BUFR code table 0-06-193. (Currently see values of 151, 152, 159.)

10

SST observation source

Numeric

See local BUFR code table 0-06-194. (Currently see values of 6, 7, 8, 9.)

11

2-digit year

Numeric

Range is 00 to 99.

12

Month of year

Numeric

Range is 1 to 12.

13-14

Latitude

degrees*100 (N+, S-)

Range is -9000 to 9000.

15-16

Longitude

degrees*100 (E+, W-)

Range is -18000 to 17999.

17

Day of month

Numeric

Range is 1 to 31.

18

Hour (UTC)

Numeric

Range is 0 to 23.

19

Minute

Numeric

Range is 0 to 59.

20

Second

Numeric

Range is 0 to 59.

21-22

SST

deg C*10

Range is -20 to 350. A value of -3000 means the data is missing.

23-24

Meaningless placeholder, ignore

=100

 

25-26

Solar zenith angle

degrees*10

Range is 0 to 1800.

27-28

Satellite zenith angle

degrees*100

Range is -600 to 600. A value of  -3000 means the data is missing.

29-30

Analyzed Field SST

deg C*10

Range is -20 to 350. A value of -3000 means the data is missing.

31-32

Meaningless placeholder, ignore

=80 or 110

 

33-34

Solar azimuth angle

degrees*10

Range is 0 to 1800. A value of -3000 means the data is missing.

35-36

Climatological SST

deg C*10

Range is -20 to 350. A value of -3000 means the data is missing.

37

Beginning row of unit array

Numeric

Range is 1 to 11.

 

38

Beginning column of unit array

Numeric

Range is 1 to 11.

39-40

AVHRR Channel 1 albedo

percent*100

Range is 0 to 10000.

41-42

AVHRR Channel 2 albedo

percent*100

Range is 0 to 10000.

43-44 – daytime for morning satellites (e.g., METOP-2, NOAA-17)

AVHRR Channel 3a albedo

percent*100

Range is 0 to 10000.

43-44 – daytime and nighttime for afternoon satellites (e.g., NOAA-19, NOAA-18); nighttime for morning satellites (e.g., METOP-2, NOAA-17)

AVHRR Channel 3b brightness temperature

K*100

Range is 0 to 32767.

45-46

AVHRR Channel 4 brightness temperature

K*100

Range is 0 to 32767.

47-48

AVHRR Channel 5 brightness temperature

K*100

Range is 0 to 32767.

49-50

Space view SDEV Channel 1 (albedo)

percent*100

Range is 0 to 10000.

(Range observed is 41 to 290)

51-52

Space view SDEV Channel 2 (albedo)

percent*100

Range is 0 to 10000.  (Range observed is 10 to 91)

53-54 – 50% of the time for morning satellites (e.g., METOP-2, NOAA-17)

Space view SDEV Channel 3a (albedo)

percent*100

Range is 0 to 10000.

(Range observed is  21 to 93)

53-54 – 100% of the time for afternoon satellites (e.g., NOAA-19, NOAA-18); 50% of the time for morning satellites (e.g., METOP-2, NOAA-17)

Space view SDEV Channel 3b (brightness temperature) (?)

K*100

Range is 0 to 32767. (Range observed is 0 to 315)

55-56

Channel 4 black body temperature

K*100

Range is 0 to 32767.

57-58

Channel 5 black body temperature

K*100

Range is 0 to 32767.

59-60

4-digit year

Numeric

Range is 1998 to present.

61-62 – when the value for byte 9 is 157 or 158

Aerosol optical thickness

m

Range is 0 to 2440. A value of -1 means that no  current data exists for the given area.

61-62 – when the value for byte 9 is something other than 157 or 158

Meaningless placeholder, ignore

 

Appears to be some type of temperature (SST, black body, brightness?) with units K*100.  A few large negative values are also observed (e.g., in the range of

 -3000  to -31000).

63-64

Spare

=0

 

65-104

Spares

=0