|DQR ID||Subject||Data Streams Affected|
|D030312.10||SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures||sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgp1mwravgC1.c1, sgp5mwravgC1.c1|
|Start Date||Start Time||End Date||End Time|
SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures
|DataStreams:||sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgp1mwravgC1.c1, sgp5mwravgC1.c1|
Several related and recurring problems with the SGP MWRs have been reported dating back to 1999. These problems were due to the occurrence of blackbody signals (in counts) that were half of those expected. The symptoms included noisy data (especially at Purcell), spikes in the data (especially at Vici), negative brightness temperatures, and apparent loss of serial communication between the computer and the radiometer, which results in a self-termination of the MWR program (especially at the CF). Because these all initially appeared to be hardware-related problems, the instrument mentor and SGP site operations personnel (1) repeatedly cleaned and replaced the fiber optic comm. components, (2) swapped radiometers, (3) sent radiometers back to Radiometrics for evaluation (which has not revealed any instrument problems), and (4) reconfigured the computer's operating system. Despite several attempts to isolate and correct it, the problem persisted. It became apparent that some component of the Windows98 configuration conflicted with the DOS-based MWR program or affected the serial port or the contents of the serial port buffer. This problem was finally corrected by upgrading the MWR software with a new Windows-compatible program.