SGP/RL/C1 - Invalid mode 0 data

On 20081112 the filter wheel for the wide field-of-view (WFOV) channel was incorrectly 
rotated. The net effect was that we were recording neutral density filter data when we 
should have been collecting data with the channels completely blocked (mode 0 data). As a 
result, the WFOV mode 0 data contains contributions from the pulse return and the solar 
background that should not be present. The mode 0 data is used in the rlprof_merge VAP to 
remove the electronic background level from the analog signal. After the problem was 
identified the filter wheel was set back to its proper rotation on 20090112.
A work-around has been implemented in the rlprof_merge VAP to handle the lack of valid 
mode 0 during the affected period. The work-around involves computing the electronic 
background from pre-pulse data during nighttime periods only. With this technique we are not 
able to estimate the range-dependence of the electronic backgound, as we did before. 
However, this range dependence is typically quite weak, and so the impact on the rlprof_merge 
output is expected to be minimal.

null

• Glue coefficient (slope) for low water vapor channel(water_counts_low_glue_coef_slope)
• Mean electronic background subtracted from the low channel elastic analog signal(electronic_background_elastic_analog_low)
• Glue coefficient (slope) for low elastic channel(elastic_counts_low_glue_coef_slope)
• Mean electronic background subtracted from the low channel nitrogen analog
  signal(electronic_background_nitrogen_analog_low)
• Number of photons counted in the low water vapor channel(water_counts_low)
• Glue coefficient (slope) for low nitrogen channel(nitrogen_counts_low_glue_coef_slope)
• Mean electronic background subtracted from the low channel water vapor analog
  signal(electronic_background_water_analog_low)
• Number of photons counted in the low elastic (aerosol) channel(elastic_counts_low)
• Glue coefficient (offset) for low elastic channel(elastic_counts_low_glue_coef_offset)
• Glue coefficient (offset) for low nitrogen channel(nitrogen_counts_low_glue_coef_offset)
• Glue coefficient (offset) for low water vapor channel(water_counts_low_glue_coef_offset)
• Number of photons counted in the low nitrogen channel(nitrogen_counts_low)

• Number of photons counted in the low water vapor channel(water_counts_low)
• Summed analog signal in the low water vapor channel(water_analog_low)
• Summed analog signal in the low nitrogen channel(nitrogen_analog_low)
• Number of photons counted in the low elastic (aerosol) channel(elastic_counts_low)
• Summed analog signal in the low elastic channel(elastic_analog_low)
• Number of photons counted in the low nitrogen channel(nitrogen_counts_low)