SGP/SWS/C1 - Temperature instability of InGaAs detector

During this time period the SWS experienced a problem with the temperature control InGaAs 
detector (for wavelength from 900-2200 nm).  The problem was initially infrequent but 
gradually increased in frequency and duration until it was chronic and nearly continual.  
All data from the InGaAs during affected period is bad and unusable, but data from the Si 
detector (300 nm to 900 nm) is unaffected.  Affected periods are easily discerned from the 
InGaAs_spect_temp (InGaAs spectrometer temperature) field in the sgpswsauxC1.b1 
datastream. When the spectrometer is behaving properly this temperature will be held steady to a 
value between -9.5 and -10.7 C.  When the temperature behaves erratically the InGaAs data 
is unusable. However the Si data is unaffected.

The spectrometer connectors were disconnected and all contacts cleaned. The problem has 
not reappeared.

Use the InGaAs spectrometer temperature to identify and screen the affected data.

• Calibrated spectrum(zen_spec_calib)

• Indium/Gallium/Arsenic spectrometer temperature(InGaAs_spect_temp)