Infrared image data in GVAR (GOES Variable Format) are scaled radiances
packaged in 10-bit words. The conversion of the raw data from the
instruments to 10-bit scaled radiances is carried out in real time in
the Sensor Processing System (SPS) at the Command and Data Acquisition
(CDA) facility at Wallops, VA, and is described elsewhere. This memo
describes how to convert a 10-bit GVAR count value (0-1023) to
temperature for channels 2-5 of the GOES I-M imagers. There are several
steps...
Start by converting the GVAR count value to a radiance, as follows:
R = (X - b)/m,
where R is radiance (mW/[m^2-sr-cm^-1]) and X is the GVAR count value.
The coefficients b and m are the scaling bias and the scaling gain,
respectively. The values of m and b are tabulated below. They depend
on the channel selected, but for a given channel they are constant for
all time and are the same for all satellites of the series.
GOES I-M Imager Scaling Coefficients
Channel m b
2 227.3889 68.2167
3 38.8383 29.1287
4 5.2285 15.6854
5 5.0273 15.3332
To convert radiance to temperature, first use the following formula
(the inverse of the Planck function) to derive "effective" temperature:
Teff = (c2*nu)/ln(1 + [c1*nu^3]/R) (1)
where Teff is effective temperature (K), "ln" stands for natural logarithm,
and R is radiance. The coefficients nu, c1, and c2 are the central
wavenumber of the channel and the two radiation constants, respectively. The
constants c1 and c2 are invariant, but nu depends on the spectral
characteristics of the channel and will vary from instrument to instrument.
The values of nu are tabulated below. The values of c1 and c2 are as
follows:
c1 = 1.191066E-5
c2 = 1.438833
Finally, to convert effective temperature Teff to actual temperature
T(K), use the following formula:
T = b*Teff + a (2)
The constants nu (cm^-1), a(K), and b depend on channel and
instrument and are tabulated below:
GOES-8 Imager (Side 1)
ch/det nu a b
2/a 2556.71 -0.578526 1.001512
2/b 2558.62 -0.581853 1.001532
3/ 1481.91 -0.593903 1.001418
4/a 934.30 -0.322585 1.001271
4/b 935.38 -0.351889 1.001293
5/a 837.06 -0.422571 1.001170
5/b 837.00 -0.466954 1.001257
GOES-9 Imager (Side 1)
ch/det nu a b
2/a 2555.18 -0.579908 1.000942
2/b 2555.18 -0.579908 1.000942
3/ 1481.82 -0.493016 1.001076
4/a 934.59 -0.384798 1.001293
4/b 934.28 -0.363703 1.001272
5/a 834.02 -0.302995 1.000941
5/b 834.09 -0.306838 1.000948
The term "Side 1" in the headings indicates that the first of the two
redundant sets of detectors and electronics is operating on each imager.
The coefficients nu, a, and b depend on the choice of side. The GOES-8 and
-9 imagers have always operated on side 1. We will provide the coefficients
for side 2 if and when they are needed.
The use of Teff accounts for the variation of the Planck function across
the spectral passband of the channel. The differences between the values of
T and Teff increase with decreasing temperature. They are usually of the
order of 0.1K. In the worst case, near 180K, they are approximately 0.3K.
A word on precision: For a scene at 300K, a change of one GVAR count is
equivalent to a temperature change of approximately 0.11K in channels 2, 4,
and 5, and a change of approximately 0.35K in channel 3.
The errors resulting from these approximations are usually between 0 and
0.01K, depending on channel and target temperatures.
It was also found that if a second-order polynomial
T = a + bTeff + cTeff^2 (3)
replaced the temperature definition in Eq. (2), it would lower the residual errors by a factor of 10. This yields errors under 0.001K, even at temperatures above 310K or under 210K.
The a, b, and c coefficients and centroid wavenumber nu for all detectors are listed in Tables 2 - 5 for the GOES -8 & -9 imagers and sounders, respectively. It is our recommendation that users apply these updated coefficients in converting GVAR radiance data to brightness temperature, especially for applications that utilize data from extremely warm or cold scenes. When the reverse conversion (i.e., from temperature T to radiance R) is required, the effective temperature Teff is first computed from T, taking the positive root of the second-order polynomial in Eq. (3),
Teff = {(b^2 - 4c[a-T])^0.5 - b} /2c
Then the radiance R is obtained from the Planck function evaluated at Teff and nu.
REFERENCES
[1] Weinreb, M.P.,"Real-world calibration of GOES -8 and -9 sensors," to appear
in the Proceedings of the SPIE Intl. Symposium on Optical Science, Engineering,
and Instrumentation; Conference on GOES-8 and Beyond, Denver, CO, 4-9 Aug.
1996.
[2] Johnson, J.X., "GOES-8 radiance to brightness-temperature conversions,"
internal memorandum, Sept. 20, 1996.
TABLE-2 GOES-8 Imager (side-1) Coefficients (9/26/96)
ch/det nu a b c
2/a 2556.71 -0.618007 1.001825 -6.021442e-07
2/b 2558.62 -0.668648 1.002221 -1.323758e-06
3/ 1481.91 -0.656443 1.001914 -9.535221e-07
4/a 934.30 -0.519333 1.002834 -3.005194e-06
4/b 935.38 -0.553431 1.002894 -3.077855e-06
5/a 837.06 -0.383077 1.000856 6.026892e-07
5/b 837.00 -0.351510 1.000340 1.761416e-06
Note:
(1) nu = centroid wavenumber
(2) T = a + bTeff + cTeff^2
(3) coefficients are valid between 180K and 340K.
TABLE-3 GOES-9 Imager (side-1) Coefficients (9/26/96)
ch/det nu a b c
2/a 2555.18 -0.592268 1.001040 -1.882973e-07
2/b 2555.18 -0.592268 1.001040 -1.882973e-07
3/ 1481.82 -0.559306 1.001602 -1.010812e-06
4/a 934.59 -0.525515 1.002411 -2.148433e-06
4/b 934.28 -0.532929 1.002616 -2.584012e-06
5/a 834.02 -0.317704 1.001058 -2.245684e-07
5/b 834.09 -0.346344 1.001261 -6.031501e-07
Note:
(1) nu = centroid wavenumber
(2) T = a + bTeff + cTeff^2
(3) coefficients are valid between 180K and 340K.
TABLE-4 GOES-8 Sounder (side-1) Coefficients (9/26/96)
ch/det nu a b c
1/1 680.60 -0.008377 1.000094 -1.456014e-07
1/2 680.51 -0.019138 1.000198 -3.647425e-07
1/3 680.81 -0.039859 1.000346 -6.312171e-07
1/4 680.73 -0.003995 1.000050 -5.457054e-08
2/1 695.92 -0.038484 0.999968 4.436424e-07
2/2 695.93 -0.024375 0.999848 6.819893e-07
2/3 696.12 -0.024090 0.999823 7.479381e-07
2/4 695.84 -0.033237 0.999984 3.567724e-07
3/1 711.80 -0.012715 1.000078 -3.886571e-08
3/2 711.86 -0.019873 1.000109 -7.394262e-08
3/3 711.96 -0.029867 1.000206 -2.774479e-07
3/4 711.81 -0.057042 1.000427 -7.032998e-07
4/1 732.48 -0.021635 1.000177 -2.648758e-07
4/2 732.40 -0.027857 1.000227 -3.631845e-07
4/3 732.46 -0.042236 1.000335 -5.667268e-07
4/4 732.47 -0.012793 1.000102 -1.193152e-07
5/1 747.75 -0.022217 0.999995 2.340048e-07
5/2 747.53 -0.013083 0.999957 2.816654e-07
5/3 747.59 -0.052569 1.000273 -3.276730e-07
5/4 747.48 -0.038935 1.000212 -2.436142e-07
6/1 790.60 -0.085267 1.000194 1.827102e-07
6/2 790.40 -0.093370 1.000280 8.410812e-09
6/3 790.36 -0.060243 1.000041 4.506944e-07
6/4 791.36 -0.096318 1.000063 5.589476e-07
7/1 827.64 -0.183131 1.001598 -2.442909e-06
7/2 830.40 -0.240993 1.000964 -6.384910e-07
7/3 829.32 -0.200440 1.001045 -1.009578e-06
7/4 827.61 -0.160297 1.001671 -2.713541e-06
8/1 906.81 -0.160929 1.000538 -1.344968e-07
8/2 906.21 -0.197024 1.000793 -5.787883e-07
8/3 906.91 -0.172274 1.000372 2.672448e-07
8/4 907.56 -0.194349 1.000450 1.396326e-07
9/1 1029.72 -0.067147 1.000312 -3.371719e-07
9/2 1029.70 -0.038978 1.000097 7.368605e-08
9/3 1029.27 -0.088297 1.000568 -8.307863e-07
9/4 1029.38 -0.068974 1.000400 -5.067042e-07
10/1 1339.77 -0.171480 1.000515 -2.700296e-07
10/2 1339.25 -0.194191 1.000786 -7.557358e-07
10/3 1339.52 -0.155085 1.000454 -1.265003e-07
10/4 1339.55 -0.175231 1.000596 -4.115346e-07
TABLE-4 GOES-8 Sounder (side-1) Coefficients (cont.)
ch/det nu a b c
11/1 1421.09 -0.287838 1.001179 -8.276922e-07
11/2 1421.86 -0.296271 1.001075 -7.250345e-07
11/3 1420.68 -0.283196 1.001339 -1.047709e-06
11/4 1422.45 -0.310130 1.001077 -7.367730e-07
12/1 1536.28 -0.156270 1.000121 1.829168e-07
12/2 1535.31 -0.166276 1.000465 -3.439521e-07
12/3 1537.53 -0.185033 0.999667 7.867531e-07
12/4 1535.05 -0.154502 1.000177 1.555637e-07
13/1 2184.80 -0.011382 1.000010 1.086815e-07
13/2 2184.80 -0.011382 1.000010 1.086815e-07
13/3 2184.80 -0.011382 1.000010 1.086815e-07
13/4 2184.80 -0.011382 1.000010 1.086815e-07
14/1 2207.56 -0.006482 0.999881 2.664836e-07
14/2 2207.56 -0.006482 0.999881 2.664836e-07
14/3 2207.56 -0.006482 0.999881 2.664836e-07
14/4 2207.56 -0.006482 0.999881 2.664836e-07
15/1 2247.57 -0.030482 0.999902 5.514106e-08
15/2 2247.57 -0.030482 0.999902 5.514106e-08
15/3 2247.57 -0.030482 0.999902 5.514106e-08
15/4 2247.57 -0.030482 0.999902 5.514106e-08
16/1 2422.08 -0.066199 1.000010 1.646631e-09
16/2 2422.08 -0.066199 1.000010 1.646631e-09
16/3 2422.08 -0.066199 1.000010 1.646631e-09
16/4 2422.08 -0.066199 1.000010 1.646631e-09
17/1 2509.40 -0.082218 1.000288 -3.273949e-07
17/2 2509.40 -0.082218 1.000288 -3.273949e-07
17/3 2509.40 -0.082218 1.000288 -3.273949e-07
17/4 2509.40 -0.082218 1.000288 -3.273949e-07
18/1 2664.70 -0.400247 1.001391 -8.968508e-07
18/2 2664.70 -0.400247 1.001391 -8.968508e-07
18/3 2664.70 -0.400247 1.001391 -8.968508e-07
18/4 2664.70 -0.400247 1.001391 -8.968508e-07
Note:
(1) nu = centroid wavenumber
(2) T = a + bTeff + cTeff^2
(3) coefficients are valid between 180K and 340K.
TABLE-5 GOES-9 Sounder (side-1) Coefficients (9/26/96)
ch/det nu a b c
1/1 681.53 -0.011921 0.999788 7.583269e-07
1/2 681.40 -0.000483 0.999740 8.084303e-07
1/3 681.53 -0.047138 0.999916 6.672041e-07
1/4 681.24 -0.018420 0.999903 4.767431e-07
2/1 694.27 -0.024488 1.000024 1.715952e-07
2/2 694.09 -0.051197 1.000288 -3.812513e-07
2/3 693.93 -0.031362 1.000195 -2.649450e-07
2/4 694.12 -0.014326 0.999994 1.835397e-07
3/1 711.40 -0.040004 1.000100 6.063910e-08
3/2 711.25 -0.037662 1.000126 -2.876325e-08
3/3 711.01 -0.018960 1.000027 1.160029e-07
3/4 711.08 -0.024055 1.000076 1.487739e-08
4/1 732.56 -0.047264 1.000220 -2.365321e-07
4/2 732.50 -0.034212 1.000135 -8.654898e-08
4/3 732.51 -0.042424 1.000177 -1.492290e-07
4/4 732.33 -0.049867 1.000274 -3.679110e-07
5/1 747.20 -0.034448 1.000052 1.378201e-07
5/2 747.18 -0.007254 0.999844 5.325268e-07
5/3 746.83 -0.005455 0.999954 2.251199e-07
5/4 746.91 -0.018135 0.999993 2.004484e-07
6/1 789.56 -0.089260 1.000409 -3.646767e-07
6/2 789.73 -0.094506 1.000409 -3.356531e-07
6/3 789.85 -0.104064 1.000435 -3.565983e-07
6/4 789.35 -0.054491 1.000187 2.464739e-08
7/1 826.88 -0.215342 1.002268 -3.924621e-06
7/2 827.23 -0.188794 1.001968 -3.305520e-06
7/3 828.27 -0.210787 1.001427 -1.889184e-06
7/4 828.68 -0.225960 1.001664 -2.389226e-06
8/1 911.22 -0.167149 0.999533 2.111074e-06
8/2 910.73 -0.176484 0.999769 1.619108e-06
8/3 909.80 -0.173227 1.000043 1.016097e-06
8/4 909.70 -0.203734 1.000412 2.577004e-07
9/1 1028.91 -0.063302 1.000176 -7.657684e-08
9/2 1028.88 -0.039983 1.000021 2.184521e-07
9/3 1028.78 -0.051837 1.000107 5.120047e-08
9/4 1028.86 -0.048593 1.000083 9.940955e-08
10/1 1335.27 -0.174663 1.000909 -9.390636e-07
10/2 1335.83 -0.174670 1.000744 -6.798345e-07
10/3 1336.05 -0.160221 1.000590 -3.982501e-07
10/4 1335.86 -0.189628 1.000860 -9.034299e-07
TABLE-5 GOES-9 Sounder (side-1) Coefficients (cont.)
ch/det nu a b c
11/1 1420.85 -0.330555 1.001482 -1.407816e-06
11/2 1421.03 -0.316028 1.001345 -1.159638e-06
11/3 1420.66 -0.332290 1.001581 -1.554169e-06
11/4 1420.77 -0.307096 1.001326 -1.103810e-06
12/1 1529.18 -0.158214 0.999918 4.425546e-07
12/2 1529.41 -0.138159 0.999657 8.791835e-07
12/3 1529.24 -0.134364 0.999803 6.685021e-07
12/4 1529.69 -0.143050 0.999647 8.714079e-07
13/1 2183.92 -0.000714 0.999874 2.890454e-07
13/2 2183.92 -0.000714 0.999874 2.890454e-07
13/3 2183.92 -0.000714 0.999874 2.890454e-07
13/4 2183.92 -0.000714 0.999874 2.890454e-07
14/1 2207.01 -0.024723 1.000003 -8.339773e-09
14/2 2207.01 -0.024723 1.000003 -8.339773e-09
14/3 2207.01 -0.024723 1.000003 -8.339773e-09
14/4 2207.01 -0.024723 1.000003 -8.339773e-09
15/1 2245.84 -0.023208 0.999900 8.983764e-08
15/2 2245.84 -0.023208 0.999900 8.983764e-08
15/3 2245.84 -0.023208 0.999900 8.983764e-08
15/4 2245.84 -0.023208 0.999900 8.983764e-08
16/1 2415.16 -0.045950 1.000048 9.048082e-08
16/2 2415.16 -0.045950 1.000048 9.048082e-08
16/3 2415.16 -0.045950 1.000048 9.048082e-08
16/4 2415.16 -0.045950 1.000048 9.048082e-08
17/1 2512.09 -0.068985 1.000120 -8.688965e-08
17/2 2512.09 -0.068985 1.000120 -8.688965e-08
17/3 2512.09 -0.068985 1.000120 -8.688965e-08
17/4 2512.09 -0.068985 1.000120 -8.688965e-08
18/1 2665.35 -0.291448 1.000793 -1.516334e-07
18/2 2665.35 -0.291448 1.000793 -1.516334e-07
18/3 2665.35 -0.291448 1.000793 -1.516334e-07
18/4 2665.35 -0.291448 1.000793 -1.516334e-07
Note:
(1) nu = centroid wavenumber
(2) T = a + bTeff + cTeff^2
(3) coefficients are valid between 180K and 340K.
UNITED STATES DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric
Administration
NATIONAL ENVIRONMENTAL SATELLITE, DATA AND INFORMATION
SERVICE
Washington, D.C. 20233
September 26, 1996
Update on GOES Radiance-Temperature Conversion Coefficients
Joy Johnson
Integral Systems, Inc
Michael Weinreb
NOAA NESDIS
In the GVAR, the infrared data received by users are scaled radiances. To
convert a scene radiance R to brightness temperature, the effective temperature
is first computed from
Teff= B-1(v0, R)
where v0 is a detector's centroid wave number and B-1 is the inverse Planck
function. The temperature is then computed from
T = a + bTeff
where a and b are the conversion coefficients determined for each detector
from our data analysis. These coefficients had been provided for both GOES -8
& -9 instruments.
In a recent study, we re-analyzed the data from which the coefflcients were
derived. The residual errors of these conversions are well below the instrument
noise level for all detectors. Nevertheless, further improvement can be made in
the coefficients for detector 2 of channels 2, 4, and 5. The updated GOES-8
irnager coefficients and ceutroid wavenumbeIs are listed m Table 1. (For
completeness, we include the GOES-9 coefficients, which are basically
unchanged.) These increase the temperature accuracy by about 0. lK, 0.08K and
0.02K for detector 2 of channels 2, 4, and 5, respectively. The coefficients for
detector 1 of these channels are basically unchanged.
It was also found that a second-order polynomial
T = a + bTeff+ cTeff^2
would describe the temperature relation with residual errors of a factor of
10 lower. This yields errors under 0.001K, even at temperatures above 310K or
under 210K.
The a, b, and c coefficients and centroid wavenumber v0 for all detectors are
listed in Tables 2-5 for the GOES -8 & -9 imagers and sounders,
respectively. It is our recommendation that users apply these updated
coefficients in converting GVAR radiance data to brightness temperature,
especially for applications that utilize data from extremely warm or cold
scenes. When the reverse conversion (i.e., from temperature T to radiance R) is
required, the effective temperature Teff first computed from T, taking the
positive root of the second-order polynomial
Teff = {SQRT[b^2 - 4c(a-T)] - b}/2c
Then the radiance R is obtained firom Planck function evaluated at Teff and
v0.
REFERENCES
Weinreb, M.P.,"Real-world calibration of GOES -8 and -9 sensors," to appear
in the Proceedings of the SPIE Intl. Symposium on Optical Science, Engineering,
an Instrumentation; Conference on GOES-8 and Beyond, Denver, CO, 4-9 Aug.
1996.
Johnson, J.X., "GOES-8 radiance to brightness-temperature conversions,"
internal memorandum, Sept. 20, 1996.
TABLE-1: GOES-8 Imager (side-1) Coefficients (9/26/96) ch/det v0 a b 2/a 2556.71 -0.578526 1.001512 2/b 2558.62 -0.581853 1.001532 3/ 1481.91 -0.593903 1.001418 4/a 934.30 -0.322585 1.001271 4/b 935.38 -0.351889 1.001293 5/a 837.06 -0.422571 1.001170 5/b 837.00 -0.466954 1.001257 GOES-9 Imager (side-1) Coefficients ch/det v0 a b 2/a 2555.18 -0.579908 1.000942 2/b 2555.18 -0.579908 1.000942 3/ 1481.82 -0.493016 1.001076 4/a 934.59 -0.384798 1.001293 4/b 934.28 -0.363703 1.001272 5/a 834.02 -0.302995 1.000941 5/b 834.09 -0.306838 1.000948 Note: (1) v0 = centroid wavenumber (2) T = a + bTeff (3) coefficients are valid between 180K and 340K TABLE-2 GOES-8 Imager (side-1) Coefficients (9/26/96) ch/det v0 a b c 2/a 2556.71 -0.618007 1.001825 -6.021442e-07 2/b 2559.62 -0.668648 1.002221 -1.323758~06 3/ 1481.91 -0.656443 1.001gl4 -9.535221e-07 4/a 934.30 -0.519333 1.002834 -3.005194e-06 4/b 935.38 -0.553431 1.002894 -3.077855e-06 5/a 837.06 -0.383077 1.000856 6.026892e-07 5/b 837.00 -0.351510 1.000340 1.761416e-06 Note: (1) v0 = centroid wavenumber (2) T = a + bTeff + cTeff^2 (3) coefficients are valid between 130K and 340K
TABLE-3 GOES-9 Imager (side-l) Coefficients (9/26/96)
ch/det v0 a b c 2/a 2555.18 -0.592268 1.001040 -1.882973e-07 2/b 2555.18 -0.592268 1.001040 -1.882973e-07 3/ 1481.82 -0.559306 1.001602 -1.010812e-06 4/a 934.59 -0.525515 1.002411 -2.148433e-06 4/b 934.28 -0.532929 1.002616 -2.584012e-06 5/a 834.02 -0.317704 1.001058 -2.245684e-07 5/b 834.09 -0.346344 1.001261 -6.031501e-07 Note: (1) v0 = centroid wavenumber (2) T = a + bTeff + cTeff^2 (3) coefficients are valid between 180K and 340K
TABLE-4 GOES-8 Sounder (side-l) Coefficients (9/26/96)
cb/det v0 a b c 1/1 680.60 -0.008377 1.000094 -1.456014-07 1/2 680.51 -0.019138 1.000198 -3.647425e-07 1/3 680.81 -0.039859 1.000346 -6.312171e-07 1/4 680.73 -0.003995 1.000050 -5.457054e-08 2/1 695.92 -0.038484 0.999968 4.436424e-07 2/2 695.93 -0.024375 0.999848 6.819893e-07 2/3 696.12 -0.024090 0.999823 7.479381e-07 2/4 695.84 -0.033237 0.999984 3.567724e-07 3/1 711.80 -0.012715 1.000078 -3.886571e-08 312 711.86 -0.019873 1.000109 -7.394262e-08 3/3 711.96 -0.029867 1.000206 -2.774479e-07 3/4 711.81 -0.057042 1.000427 -7.032998e-07 4/1 732.48 -0.021635 1.000177 -2.648758e-07 4/2 732.40 -0.027857 1.000227 -3.631845e-07 413 732.46 -0.042236 1.000335 -5.667268e-07 4/4 732.47 -0.012793 1.000102 -1.193152e-07 5/1 747.75 -0.022217 0.999995 2.340048e-07 5/2 747.53 -0.013083 0.999957 2.816654e-07 5/3 747.59 -0.052569 1.000273 -3.276730e-07 5/4 747.48 -0.038935 1.000212 2 436142e-07 6/1 790.60 -0.085267 1.000194 1.827102e-07 6i2 790.40 -0.093370 1.000280 8.410812e-09 6/3 790.36 -0.060243 1.000041 4.506944e-07 674 791.36 -0.096318 1.000063 5.589476e-07 7/1 827.64 -0.183131 1.001598 -2.442909e-06 7/2 830.40 -0.240993 1.000964 -6.384910e-07 7/3 829.32 -0.200440 1.001045 -1.009578e-06 7/4 827.61 -0.160297 1.001671 -2.713541e-06 8/1 906.81 -0.160929 1.000538 -1.344968e-07 8/2 906.21 -0.197024 1.000793 -5.787883e-07 8/3 906.91 -0.172274 1.000372 2.672448e-07 8/4 907.56 -0.194349 1.000450 1.396326e-07 9/1 1029.72 -0.067147 1.000312 -3.371719e-07 9/2 1029.70 -0.038978 1.000097 7.368605e-08 9/3 1029.27 -0.088297 1.000568 -8.307863e-07 9/4 1029.38 -0.068974 1.000400 -5.067042e-07 10/1 1339.77 -0.171480 1.000515 -2.700296e-07 10/2 1339.25 -0.194191 1.000786 -7.557358e-07 10/3 1339.52 -0.155085 1.000454 -1.265003e-07 10/4 1339.55 -0.175231 1.000596 -4.115346e-07 11/1 1421.09 -0.287838 1.001179 -8.276922e-07 11/2 1421.86 -0.296271 1.001075 -7.250345e-07 11/3 1420.68 -0.283196 1.001339 -1.047709e-06 11/4 1422.45 -0.310130 1.001077 -7.367730e-07 12/1 1536.28 -0.156270 1.000121 1.829168e-07 12/2 1535.31 -0.166276 1.000465 -3.439521e-07 12/3 1537.53 -0.185033 0.999667 7.867531e-07 12/4 1535.05 -0.154502 1.000177 1.555637e-07 13/1 2184.80 -0.011382 1.000010 1.086815e-07 13/2 2184.80 -0.011382 1.000010 1.086815e-07 13/3 2184.80 -0.011382 1.000010 1.086815e-07 13/4 2184.80 -0.011382 1.000010 1.086815e-07 14/1 2207.56 -0.006482 0.999881 2.664836e-07 14/2 2207.56 -0.006482 0.999881 2.664836e-07 14/3 2207.56 -0.006482 0.999881 2.664836e-07 14/4 2207.56 -0.006482 0.999881 2.664836e-07 15/1 2247.57 -0.030482 0.999902 5.5l4106e-08 15/2 2247.57 -0.030482 0.999902 5.514106e-08 15/3 2247.57 -0.030482 0.999902 5.514106e-08 15/4 2247.57 -0.030482 0.999902 5.514106e-08 16/1 2422.08 -0.066199 1.000010 1.646631e-09 16/2 2422.08 -0.066199 1.000010 1.646631e-09 16/3 2422.08 -0.066199 1.000010 1.646631e-09 16/4 2422.08 -0.066199 1.000010 1.646631e-09 17/1 2509.40 -0.082218 1.000288- -3.273949e-07 17/2 2509.40 -0.082218 1.000288 -3.273949e-07 17/3 2509.40 -0.082218 1.000288 -3.273949e-07 17/4 250g.40 -0.082218 ].000288 -3.273949e-07 18/1 2664.70 -0.400247 1.001391 -8.968508e-07 18/2 2664.70 -0.400247 1.00139l -8.968508e-07 18/3 2664.70 -0.400247 1.001391 -8.968508e-07 18/4 2664.70 -0.400247 1.001391 -8.968508e-07 Note: (1) v0 = centroid wavenumber (2) T= a + bTeff + cTeff^2 (3) coefficients are valid between 180K and 340K
TABLE-5 GOES-9 Sounder (side-l) Coefficients(9/26/96)
ch/det v0 a b c 1/1 681.53 -0.011921 0.999788 7.583269e-07 1/2 681.40 -0.000483 0.999740 8.084303e-07 1/3 681.53 -0.047138 0.999916 6.672041e-07 1/4 681.24 -0.018420 0.999903 4.767431e-07 2/1 694.27 -0.024488 1.000024 1.715952e-07 2/2 694.09 -0.051197 1.000288 -3.812513e-07 2/3 693.93 -0.031362 1.000195 -2.649450e-07 2/4 694.12 -0.014326 0.999994 1.835397e-07 3/1 711.40 -0.040004 1.000100 6.063910e-08 3/2 711.25 -0.037662 1.000126 -2.876325e-08 3/3 711.01 -0.018960 1.000027 1.160029e-07 3/4 711.08 -0.024055 1.000076 1.487739e-08 4/1 732.56 -0.047264 1.000220 -2.365321e-07 4/2 732.50 -0.034212 1.000135 -8.654898e-08 4/3 732.51 -0.042424 1.000177 -1.492290e-07 4/4 732.33 -0.049867 1.000274 -3.679110e-07 5/1 747.20 -0.034448 1.000052 1.378201e-07 5/2 747.18 -0.007254 0.999844 5.325268e-07 5/3 746.83 -0.005455 0.999954 2.251199e-07 5/4 746.91 -0.018135 0.999993 2.004484e-07 6/1 789.56 -0.089260 1.000409 -3.646767e-07 6/2 789.73 -0.094506 1.000409 -3.356531e-07 6/3 789.85 -0.104064 1.000435 -3.565g83e-07 6/4 789.35 -0.054491 1.000187 2.464739e-08 7/1 826.88 -0.215342 1.002268 -3.924621e-06 7/2 827.23 -0.188794 1.001968 -3.305520e-06 7/3 828.27 -0.210787 1.001427 -1.889184e-06 7/4 828.68 -0.225960 1.001664 -2.389226e-06 8/1 911.22 -0.167149 0.999533 2.111074e-06 8/2 910.73 -0.176484 0.999769 1.619108e-06 8/3 909.80 -0.173227 1.000043 1.016097e-06 8/4 909.70 -0.203734 1.000412 2.577004e-07 9/1 1028.91 -0.063302 1.000176 -7.657684e-08 9/2 1028.88 -0.039983 1.000021 2.184521e-07 913 1028.78 -0.051837 1.000107 5.120047e-08 9/4 1028.86 -0.048593 1.000083 9.940955e-08 10/1 1335.27 -0.174663 1.000909 -9.390636e-07 10/2 1335.83 -0.174670 1.000744 -6.798345e-07 1013 1336.05 -0.160221 1.000590 -3.982501e-07 1014 1335.86 -0.189628 1.000860 -9.034299e-07 11/1 1420.85 -0.330555 1.001482 -1.407816e-06 11/2 1421.03 -0.316028 1.001345 -1.159638e-06 11/3 1420.66 -0.332290 1.001581 -1.554169e-06 11/4 1420.77 -0.307096 1.001326 -1.103810e-06 12/1 1529.18 -0.158214 0.999918 4.425546e-07 12/2 1529.41 -0.138159 0.999657 8.791835e-07 12/3 1529.24 -0.134364 0.999803 6.685021e-07 12/4 1529.69 -0.143050 0.999647 8.714079e-07 13/1 2183.92 -0.000714 0.999874 2.890454e-07 13/2 2183.92 -0.000714 0.999874 2.890454e-07 13/3 2183.92 -0.000714 0.999874 2.890454e-07 13/4 2183.92 -0.000714 0.999874 2.890454e-07 14/1 2207.01 -0.024723 1.000003 -8.339773e-09 14/2 2207.01 -0.024723 1.000003 -8.339773e-09 14/3 2207.01 -0.024723 1.000003 -8.339773e-09 14/4 2207.01 -0.024723 1.000003 -8.339773e-09 15/1 2245.84 -0.023208 0.999900 8.983764e-08 15/2 2245.84 -0.023208 0.999900 8.983764e-08 15/3 2245.84 -0.023208 0.999900 8.983764e-08 15/4 2245.84 -0.023208 0.999900 S.983764e-08 16/l 2415.16 -0.045950 i.000048 9.048082e-08 16/2 2415.16 -0.045950 1.000048 9.048082e-08 16/3 2415.16 -0.045950 1.000048 9.048082e-08 16/4 2415.16 -0.045950 1.000048 9.048082e-08 17/1 2512.09 -0.068985 1.000120 -8.688965e-08 17/2 2512.09 -0.068985 1.000120 -8.688965e-08 17/3 2512.09 -0.068985 1.000120 -8.688965e-08 17/4 2512.09 -0.068985 1.000120 -8.688965e-08 18/1 2665.35 -0.291448 1.000793 -1.516334e-07 18/2 2665.35 -0.291448 1.000793 -1.516334e-07 18/3 2665.35 -0.291448 1.000793 -1.516334~07 18/4 2665.35 -0.291448 1.000793 -1.516334e-07 Note: v0 = centroid wavenumber (2) T = a + bTeff - cTeff^2 (3) coefficients are valid between 180K and 340K
Date: Mon, 18 Nov 1996 14:24:54 +0500
X-Sender: pcelone@nesdis.noaa.gov
Subject: Off-line Calibration update
Important notice to users of GOES-8 Imager data:
NOAA has corrected a small error in the infrared spectral response
functions used in off-line processing for the GOES-8 Imager. This has
resulted in new values for the coefficients and look-up tables that are used
off-line to convert GVAR counts and radiances to brightness temperatures.
Coefficients and tables in the operational, on-line processing at the
Command and Data Acquisition Station at Wallops VA were never in error and
are not being changed.
The new values of the coefficients nu, a, and b (used in the approximation to
compute brightness temperatures from radiances) have been inserted in the
GOES calibration section of the Office of Satellite Operations
Web page (http://www.nnic.noaa.gov/SOCC/SOCC_Home.html) on October 11, 1996.
Users of the ten-bit counts-to-temperatures look-up tables and the spectral
response functions themselves should contact Pete Celone to obtain updates
of those items.
The errors affect only the spectral response functions of three
detectors: detector 2 of channels 2, 4, and 5. The resulting errors in
radiance-to-brightness temperature computations varied with target
temperature and had maximum values of 0.10K, 0.08K, and 0.02K, respectively,
for the three detectors. The corrections reduce the computational errors to
under 0.015K for all detectors. The corrected values of brightness
temperature are slightly higher than the old values.
--
Peter J. Celone
Office of Satellite Operations
301-457-5130
pcelone@nesdis.noaa.gov