High Resolution Infra Red
Radiation Sounder/2
(HIRS/2)
| The High Resolution Infra Red Radiation Sounder (HIRS/2) flies on the NOAA/TIROS-N
type satellites and provides the basic 20 channel IR temperature and
humidity soundings of the TOVS system. All HIRS/2 channels are used to
provide information on temperature and humidity profiles, surface temperature,
cloud parameters and total ozone. Calibration of HIRS/2 is performed
every 40 scan lines, there is a gap of three scan lines in data coverage..
HIRS scans across track in a ‘stop and stare’ mode at a scan rate of
6.4 sec. There are 56 Earth Views per scan. The circular field-of-views
have a diameter of 20 km at nadir. The swath covers ± 1080 km. |
| HIRS/2 sounder channel characteristics |
|
| Channel |
Centre
Wave number
(cm-1) |
Centre
Frequency
(mm) |
Half Bandwidth
(cm-1) |
Anticipated Max. Scene Temperature
(K) |
Specified NEDN
(mW/m2/
sterad/cm-1) |
| 1 |
669 |
14.95 |
3 |
280 |
3.00 |
| 2 |
680 |
14.71 |
10 |
265 |
0.67 |
| 3 |
690 |
14.49 |
12 |
240 |
0.50 |
| 4 |
703 |
14.22 |
16 |
250 |
0.31 |
| 5 |
716 |
13.97 |
16 |
265 |
0.21 |
| 6 |
733 |
13.64 |
16 |
280 |
0.24 |
| 7 |
749 |
13.35 |
16 |
290 |
0.20 |
| 8 |
900 |
11.11 |
35 |
330 |
0.10 |
| 9 |
1030 |
9.71 |
25 |
270 |
0.15 |
| 10 |
797 |
12.55 |
16 |
290 |
0.20 |
| 11 |
1365 |
7.33 |
40 |
275 |
0.20 |
| 12 |
1488 |
6.72 |
80 |
260 |
0.19 |
| 13 |
2190 |
4.57 |
23 |
300 |
0.006 |
| 14 |
2210 |
4.52 |
23 |
290 |
0.003 |
| 15 |
2240 |
4.46 |
23 |
280 |
0.004 |
| 16 |
2270 |
4.40 |
23 |
260 |
0.002 |
| 17 |
2360 |
4.24 |
23 |
280 |
0.002 |
| 18 |
2240 |
4.13 |
28 |
330 |
0.002 |
| 19 |
2660 |
3.76 |
100 |
340 |
0.001 |
| 20 |
14500 |
0.69 |
1000 |
100 % Alb. |
0.10 % A |
|
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