NOAA Office of Satellite and Product Operations

NOAA 18 AMSU-A2 Subsystem Summary

Component Description Status
CHANNEL 1Radiometer channel 1, 23800 MHzGreen
CHANNEL 2Radiometer channel 2, 31400 MHzGreen
GUN DIODE OSCGun Diode OscillatorGreen
MIXER IF AMPMixer Intermediate Frequency AmplifierGreen
SCAN MOTORInstrument Scan MotorGreen
SIGNAL PROCESSORSignal ProcessorGreen

Subsystem History:

Date Time Component Description
02/07/200803:10:00 The NOAA-18 AMSU-A2 instrument began showing unusual reading in its Digital-A telemetry starting at 03:10 GMT the morning of 7 February 2008 (2008/038). At that time, there was a downward shift seen in the Internal Warm Target temperature, the temperature sensor reference voltage began fluctuating rapidly with values over a range of approximately 500 raw counts, and many of the Digital-A temperatures also began rapid fluctuations in value. Additionally, there were shifts in the radiometric levels in the IWT and Cold Cal views. As a result of the inconsistent values being reported for the various temperatures and the drifts in radiometric values, data processing has been affected. The NEdT values for the two AMSU-A2 channels have risen to roughly twice their previous levels.
09/30/200721:39:00 On 07/273, AMSU A2 Cold Cal Position and Cold Cal Select position changed to 0,POS2 respectively (from 1, POS1). The DC Converter temperature began to rise, causing other temperatures to rise. DC Converter Temps leveled off at 306-207.5K as of 07/275.
07/27/200520:15:00 Select Space View Position 2 and recover from unexpected configuration.
07/26/200517:10:00 After being commanded to Warm View, AMSU-A2 did not return to expected configuration one rev later. Symptoms show as miscompares on P2COLDC and DAM2CALL mnemonics.
07/26/200517:06:00 Return AMSU-A2 to full scan, test complete.
07/26/200515:41:00 Park AMSU-A2 at warm target to support HIRS TOAR invesitgation
06/08/200501:35:00 AMSU-A2 to space view-2
06/05/200519:05:00 AMSU-A2 to space view-1.
06/03/200519:20:00 AMSU-A2 commanded to space view-3
06/01/200519:40:00 AMSU-A2 commanded to space view 4
05/30/200521:48:00 AMSU-A2 commanded to space position 2
05/24/200519:25:30CHANNEL 2on orbit, operational
05/24/200519:25:00CHANNEL 1on orbit, operational
05/24/200519:23:00SIGNAL PROCESSORturned on, operational
05/24/200519:22:00SCAN MOTORturned on, operational
05/24/200519:21:00RECEIVERturned on, operational
05/24/200519:20:30MIXER IF AMPturned on, operational
05/24/200519:20:20COMPENSATORturned on, on orbit
05/24/200519:20:10ANTENNAAMSU-A2 turnon, antenna operational
05/24/200519:20:00 AMSU-A2 powered on, nominal.
05/24/200519:20:00GUN DIODE OSCturned on, operational.
05/20/200511:58:00 AMSU-A2 survival heater nominally turned on instrument not yet powered up.