# Section 1.4.9

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## 1.4.9 NOAA-13

Operational dates: Aug. 9, 1993 - Aug. 21, 1993

Afternoon orbit: 1340 LST ascending node, 0140 descending node

AVHRR instrument: 5 channels

Spacecraft ID: 3

Table 1.4.9-1 contains the central wave numbers for the AVHRR IR channels for NOAA-13. Table 1.4.9-2 contains the TOVS channel spectral response and HIRS/2 thermal band-correction coefficients for NOAA-13. Non-linearity corrections for NOAA-13 AVHRR Channels 4 and 5 are contained in Table 1.4.9-3. The non-linearity correction can be obtained from Table 1.4.9-3 by interpolation on the scene temperatures and the temperatures of the AVHRR's internal calibration target.

With the launch of NOAA-13, NESDIS changed their method of handling the non-linearity correction. See Section 3.3.1.2 for NESDIS' alternate method for calculating the non-linearity correction. Use Equation 3.3.1.2-1 to calculate the corrected radiance. Table 1.4.9-4 contains the coefficients A, B, and D for the quadratic equation in Equation 3.3.1.2-1 and the radiance of space which are required to calculate the corrected radiance.

Figures 1.4.9-1 through 1.4.9-5 contain the spectral response curves for NOAA-13 AVHRR channels 1 through 5, respectively.

Table 1.4.9-1. NOAA-13Central Wave Numbers for AVHRR IR Channels.
Temperature Range (K) Channel 3 (cm-1) Channel 4 (cm-1) Channel 5 (cm-1)
190-230 2636.124 924.0114 836.1164
230-270 2640.147 924.5165 836.4339
270-310 2643.153 924.9732 836.7651
290-330 2644.382 925.2164 836.9520
Note: The 270-310 K range is applicable for sea surface temperatures.

Table 1.4.9-2. NOAA-13 TOVS Channel Spectral Response and HIRS/2 Thermal Band-Correction Coefficients.
Instrument Channel # Central Wave # Description HIRS/2 Band-Correction Coefficients
b c
HIRS/2 1 668.81 cm-1 15 micrometers -0.077 1.00019
2 679.59 cm-1 CO2 Band 0.020 0.99992
3 690.18 cm-1 CO2 Band 0.016 0.99993
4 703.02 cm-1 CO2 Band 0.018 0.99991
5 715.96 cm-1 CO2 Band 0.040 0.99986
6 732.98 cm-1 CO2 Band 0.028 0.99987
7 749.34 cm-1 CO2 Band -0.034 1.00000
8 902.39 cm-1 Window 0.544 0.99916
9 1028.77 cm-1 Ozone 0.062 0.99979
10 792.82 cm-1 Water Vapor -0.005 0.99994
11 1359.95 cm-1 Water Vapor 0.090 0.99972
12 1479.90 cm-1 Water Vapor 0.292 0.99931
13 2189.06 cm-1 4.3 micrometers 0.022 0.99997
14 2212.55 cm-1 CO2 Band 0.021 0.99997
15 2231.68 cm-1 CO2 Band 0.029 0.99993
16 2267.04 cm-1 CO2 Band 0.022 0.99999
17 2418.31 cm-1 CO2 Band 0.025 0.99992
18 2516.80 cm-1 Window 0.058 0.99970
19 2653.33 cm-1 Window 0.264 0.99927
20 14453.14 cm-1 Visible Window n/a n/a
MSU 1 1.6779 cm-1 n/a n/a n/a
2 1.7927 cm-1 n/a n/a n/a
3 1.8334 cm-1 n/a n/a n/a
4 1.9331 cm-1 n/a n/a n/a
SSU 1 669.988 cm-1/15 mb n/a n/a n/a
2 669.628 cm-1/5 mb n/a n/a n/a
3 669.357 cm-1/1.5 mb n/a n/a n/a

Table 1.4.9-3. Non-linearity errors for NOAA-13 AVHRR Channels 4 and 5.
Scene temperature (K) Temperature Corrections
Channel 4 Channel 5
320 0.25 0.20
315 0.07 0.03
310 -0.01 -0.02
305 -0.09 -0.06
295 -0.00 0.01
285 0.07 0.01
275 0.24 0.13
265 0.87 0.40
255 1.47 0.70
245 2.14 1.05
235 3.32 1.43
225 4.53 2.27
215 5.93 3.02
205 9.42 3.96

Table 1.4.9-4. Non-linearity coefficients and radiance of space for NOAA-13 AVHRR Channels 4 and 5 (Alternate method).
Radiance Correction Coefficients Channel 4 Channel 5
A 0.91159 0.94784
B 0.0003820 0.0002057
D 5.01 3.24
Radiance of Space, Rsp -5.31 -3.28

Table 1.4.9-5. PRT coefficients for all instruments on NOAA-13 (from NESS 107, App. B).
AVHRR
PRT counts to temperature coefficients
PRT a0 a1 a2 a3 a4
1 276.597 0.051275 1.363E-6 0.0 0.0
2 276.597 0.051275 1.363E-6 0.0 0.0
3 276.597 0.051275 1.363E-6 0.0 0.0
4 276.597 0.051275 1.363E-6 0.0 0.0
PRT weighting factors
b1 b2 b3 b4
0.25 0.25 0.25 0.25
HIRS
IWT PRT Count to temperature coefficients
PRT a0 a1 a2 a3 a4
1 301.37210 6.52057E-03 9.05197E-08 4.73741E-11 8.29062E-16
2 301.37560 6.52283E-03 9.13565E-08 4.73871E-11 7.86019E-16
3 301.41250 6.51819E-03 9.18444E-08 4.75139E-11 7.30508E-16
4 301.37420 6.51875E-03 9.04524E-08 4.72894E-11 8.06020E-16
SSU
PRT count to temperature coefficients
a0 a1 a2
284.125 4.819E-03 8.75E-09
Thermistor to temperature coefficients
b0 b1 b2 b3
375.969 -203.161 179.13 -85.16
c0 c1 c2 c3
375.969 -203.161 179.13 -85.16
MSU
PRT Count to resistance coefficients
e0 e1 e2
1A 28.74552 .4278088 .3056633E-04
2A 28.86749 .4263018 .3083285E-04
1B 28.73856 .4335265 .3147607E-04
2B 28.67430 .4282688 .3054580E-04