SGP/VCEIL/C1 - poor signal

When parameters were changed (set noise_h2_compensation to "ON" and units to "METERS") to 
correct a low amplitude problem, the backscatter plots began displaying horizontal 
stripes indicating detector "ringing". However, the cloud base heights are not affected. The 
problem was corrected when the instrument was replaced.

• Detection status. See details(detection_status)
• Aerosol backscatter coefficient at 355 nm(backscatter)

SGP/VCEIL/C1 - low amplitude

When the instrument was replaced with a spare, the backscatter plots began displaying a 
suspiciously low amount of amplitude (noise) but the cloud base heights were not affected. 

Discovered that when the vendor repaired this unit in August 2004, noise compensation was 
set to "OFF". Changed the parameters to "ON".

Also noted that the measurement units was set to "FEET".  This was changed to "METERS.  
The heights are not affected because the ingest recognizes the raw data units and 
automatically converts to meters.

• Aerosol backscatter coefficient at 355 nm(backscatter)

• Percentage of nominal factory setting (0 to 999%)(receiver_sensitivity)
• lon(lon)
• Lowest cloud base height detected.(first_cbh)
• base time(base_time)
• Millivolts at internal ADC input(window_contamination)
• Degrees from vertical (0 to +90)(tilt_angle)
• lat(lat)
• Altitude of highest signal(alt_highest_signal)
• Dummy altitude for Zeb(alt)
• 6 character string describing instrument measurement parameters(measurement_parameters)
• Laser temperature(laser_temperature)
• Second lowest cloud base height(second_cbh)
• Percentage of nominal factory setting (0 to 999%)(laser_pulse_energy)
• range(range)
• Vertical visibility(vertical_visibility)
• Backscatter sum(sum_backscatter)
• Millivolts at internal ADC input (0 to 2500)(background_light)
• Warning and alarm status bits(status_string)
• Detection status. See details(detection_status)
• Aerosol backscatter coefficient at 355 nm(backscatter)
• Flag indicating aeri retrieval status(status_flag)
• Third cloud base height(third_cbh)
• Time offset of tweaks from base_time(time_offset)