AMSU-A Level 1B Calibrated, Geolocated Radiances

AMSU-A Level 1B data sample product

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The AMSU-A level 1B data set contains AMSU-A calibrated and geolocated brightness temperatures in degrees Kelvin. This data set is generated from AMSU-A Level 1A digital numbers (DN), including 15 microwave channels in the 50 - 90 GHz and 23 - 32 GHz regions of the spectrum. A day's worth of data is divided into 240 scenes each of 6 minute duration. An AMSU-A scene contains 30 cross-track footprints in each of 45 along-track scanlines, for a total of 45 x 30 = 1350 footprints per scene. The AMSU-A is co-aligned with the AIRS instrument onboard the Aqua platform so that successive blocks of 3 x 3 AIRS footprints are contained within the AMSU-A footprint.

AMSU-A is primarily a temperature sounder that provides atmospheric information in the presence of clouds, which can be used to correct the AIRS infrared measurements for the effects of clouds. This is possible because non-precipitating clouds are for the most part transparent to microwave radiation, in contrast to visible and infrared radiation which are strongly scattered and absorbed by clouds. Combined with simultaneous measurements from the AIRS and HSB instruments, the calibrated AMSU-A brightness temperatures will also be used to initialize the surface temperature and atmospheric temperature profile required for the retrieval of the final AIRS geophysical products. AMSU level 1B daily summary browse product is also available to provide users with a global quick look capability when searching for data of interest.

GES DISC Data Access

ESDT Shortname:
AIRABRAD

Coverage:
Global, Twice Daily
(Daytime and Nighttime)

Resolution:
40.5 km FOV at nadir

Spectral Range:
AMSU-A1: 13 channels from 50 - 90 GHz
AMSU-A2: 2 channels from 23 - 32 GHz 

Volume:
0.6 MB/file, 240 files/day

Product Guide:
AIRS User Guide

Instrument Guide:
AMSU-A Instrument Guide

To plot AMSU brightness temperatures 
on satellite projection: 
(can save the image as well)
 
idl -novm -rt=airs1b_look.sav –args 
filename channel_number(option) 
AIRS.2003.07.13.060.L1B.AMSU_Rad.v5.
0.0.0.G07090194232.hdf 1 default channel=3 (50300.0 MHz)
amsuFrequency = [23800.0, 31400.0, 
50300.0, 52800.0, 53596.0, 54400.0, 
54940.0, 55500.0, 57290.0, 57290.0, 
57290.0, 57290.0, 57290.0, 
57290.0, 89000.0] MHz