NOAA Office of Satellite and Product Operations

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
Sensiitivity
(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 )