AMSU-A Overview
The Advanced Microwave Sounding Unit-A (AMSU-A) is a 15-channel cross- track, stepped-line scanning, total power microwave radiometer. The instrument has an instantaneous field-of-view of 3.3° at the half-power points providing a nominal spatial resolution at nadir of 48 km (29.8 mi). The antenna provides a cross-track scan, scanning ±48.3° from nadir with a total of 30 Earth fields-of-view per scan line. This instrument completes one scan every 8 seconds.
AMSU-A Channel Characteristics |
Channel Number |
Central Freq. (MHz) |
# Bands |
Nominal Bandwidth (MHz) |
Nominal Beamwidth (MHz) |
Central Frequency Stability (MHz) |
Temperature Sensitivity (K) NEΔT |
Calibration Accuracy (K) |
Polarization at nadir |
1 |
23800 |
1 |
270 |
3.3 |
10 |
0.3 |
2.0 |
V |
2 |
31400 |
1 |
180 |
3.3 |
10 |
0.3 |
2.0 |
V |
3 |
50300 |
1 |
180 |
3.3 |
10 |
0.4 |
1.5 |
V |
4 |
52800 |
1 |
400 |
3.3 |
5 |
0.25 |
1.5 |
V |
5 |
53596 ±115 |
2 |
170 |
3.3 |
5 |
0.25 |
1.5 |
H |
6 |
54400 |
1 |
400 |
3.3 |
5 |
0.25 |
1.5 |
H |
7 |
54940 |
1 |
400 |
3.3 |
5 |
0.25 |
1.5 |
V |
8 |
55500 |
1 |
330 |
3.3 |
10 |
0.25 |
1.5 |
H |
9 |
57290.344 |
1 |
330 |
3.3 |
0.5 |
0.25 |
1.5 |
H |
10 |
57290.344 ±217 |
2 |
78 |
3.3 |
0.5 |
0.4 |
1.5 |
H |
11 |
57290.344 ±322.2 ±48 |
4 |
36 |
3.3 |
1.2 |
0.4 |
1.5 |
H |
12 |
57290.344 ±322.2 ±22 |
4 |
16 |
3.3 |
1.2 |
0.6 |
1.5 |
H |
13 |
57290.344 ±322.2 ±10 |
4 |
8 |
3.3 |
0.5 |
0.80 |
1.5 |
H |
14 |
57290.344 ±322.2 ±4.5 |
4 |
3 |
3.3 |
0.5 |
1.20 |
1.5 |
H |
15 |
89000 |
1 |
<6000 |
3.3 |
50 |
0.5 |
2.0 |
V |
V: Polarization vector is parallel to scan plane at nadir
H: Polarization vector is perpendicular to scan plane at nadir
Source: NOAA KLM User's Guide (
www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/klm/html/c3/sec3-3.htm
)