NOAA 18 AMSU-A2 Subsystem Summary

Component	Description	Status
ANTENNA	Antenna	Green
CHANNEL 1	Radiometer channel 1, 23800 MHz	Green
CHANNEL 2	Radiometer channel 2, 31400 MHz	Green
COMPENSATOR	Compensator	Green
GUN DIODE OSC	Gun Diode Oscillator	Green
MIXER IF AMP	Mixer Intermediate Frequency Amplifier	Green
RECEIVER	Receiver	Green
SCAN MOTOR	Instrument Scan Motor	Green
SIGNAL PROCESSOR	Signal Processor	Green

Subsystem History:

Date	Time	Component	Description
02/07/2008	03:10:00		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.
09/30/2007	21:39:00		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.
07/27/2005	20:15:00		Select Space View Position 2 and recover from unexpected configuration.
07/26/2005	17:10:00		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.
07/26/2005	17:06:00		Return AMSU-A2 to full scan, test complete.
07/26/2005	15:41:00		Park AMSU-A2 at warm target to support HIRS TOAR invesitgation
06/08/2005	01:35:00		AMSU-A2 to space view-2
06/05/2005	19:05:00		AMSU-A2 to space view-1.
06/03/2005	19:20:00		AMSU-A2 commanded to space view-3
06/01/2005	19:40:00		AMSU-A2 commanded to space view 4
05/30/2005	21:48:00		AMSU-A2 commanded to space position 2
05/24/2005	19:25:30	CHANNEL 2	on orbit, operational
05/24/2005	19:25:00	CHANNEL 1	on orbit, operational
05/24/2005	19:23:00	SIGNAL PROCESSOR	turned on, operational
05/24/2005	19:22:00	SCAN MOTOR	turned on, operational
05/24/2005	19:21:00	RECEIVER	turned on, operational
05/24/2005	19:20:30	MIXER IF AMP	turned on, operational
05/24/2005	19:20:20	COMPENSATOR	turned on, on orbit
05/24/2005	19:20:10	ANTENNA	AMSU-A2 turnon, antenna operational
05/24/2005	19:20:00		AMSU-A2 powered on, nominal.
05/24/2005	19:20:00	GUN DIODE OSC	turned on, operational.
05/20/2005	11:58:00		AMSU-A2 survival heater nominally turned on instrument not yet powered up.