SGP/RL/C1 - Degraded sensitivity in WFOV channels

The sensitivity of all the wide field-of-view (WFOV) channels was abnormally low due a 
malfunction of the filter wheel. The filter wheel for the WFOV channels did not rotate into 
position properly and thus partially obscured the return light.

• Fit parameters for the low elastic channel(parameters_elastic_low)
• Solar background in the low channel nitrogen channel(solar_background_nitrogen_low)
• Glue coefficient (offset) for low water vapor channel(water_counts_low_glue_coef_offset)
• Glue coefficient (slope) for low elastic channel(elastic_counts_low_glue_coef_slope)
• Glue coefficient (slope) for low nitrogen channel(nitrogen_counts_low_glue_coef_slope)
• Fit parameters for the low nitrogen channel(parameters_nitrogen_low)
• Solar background in the low channel water channel(solar_background_water_low)
• Glue coefficient (slope) for low water vapor channel(water_counts_low_glue_coef_slope)
• Glue coefficient (offset) for low nitrogen channel(nitrogen_counts_low_glue_coef_offset)
• Glue coefficient (offset) for low elastic channel(elastic_counts_low_glue_coef_offset)
• Fit parameters for the low water vapor channel(parameters_water_low)
• Count rate in the low water vapor channel(water_counts_low)
• Count rate in the low nitrogen channel(nitrogen_counts_low)
• Solar background in the low channel elastic channel(solar_background_elastic_low)
• Count rate in the low elastic channel(elastic_counts_low)

• Summed analog signal in the low water vapor channel(water_analog_low)
• Count rate in the low water vapor channel(water_counts_low)
• Summed analog signal in the low elastic channel(elastic_analog_low)
• Count rate in the low nitrogen channel(nitrogen_counts_low)
• Summed analog signal in the low nitrogen channel(nitrogen_analog_low)
• Count rate in the low elastic channel(elastic_counts_low)

SGP/RL/C1 - No liquid water data in RLPROFmerge

From 20060906 to 20080304 the liquid water channel (LWC) was disabled due to the removal 
of its photomultiplier tube (PMT).  During this period the signals recorded in the 
sgprlC1.a0 files for the LWC contain invalid data, and so the decision was made not have the 
rlprof_merge vap process the LWC data. As a result, the sgprlprofmerge1turnC1.c0.*.cdf files 
contain NO LWC fields (variables or attributes) during this period.
   
Do not attempt to read any fields (variables or attributes) associated with the liquid 
water channel in the sgprlprofmerge1turnC1.c0.*.cdf files between the dates of 20060906 
through 20080304.

• Adjustment to ensure solar background from AD and PC data are identical for the
  high liquid channel(solar_offset_nudge_lw)
• Count rate in the high liquid channel(liquid_counts_high)
• Glue coefficient (offset) for high liquid channel(liquid_counts_high_glue_coef_offset)
• Fit parameters for the high liquid channel(parameters_liquid_high)
• Glue coefficient (slope) for high liquid channel(liquid_counts_high_glue_coef_slope)

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.

• Mean electronic background subtracted from the low channel elastic analog signal(electronic_background_elastic_analog_low)
• Glue coefficient (offset) for low water vapor channel(water_counts_low_glue_coef_offset)
• Mean electronic background subtracted from the low channel water vapor analog
  signal(electronic_background_water_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)
• Glue coefficient (slope) for low nitrogen channel(nitrogen_counts_low_glue_coef_slope)
• Glue coefficient (slope) for low water vapor channel(water_counts_low_glue_coef_slope)
• Glue coefficient (offset) for low nitrogen channel(nitrogen_counts_low_glue_coef_offset)
• Glue coefficient (offset) for low elastic channel(elastic_counts_low_glue_coef_offset)
• Count rate in the low water vapor channel(water_counts_low)
• Count rate in the low nitrogen channel(nitrogen_counts_low)
• Count rate in the low elastic channel(elastic_counts_low)

• Summed analog signal in the low water vapor channel(water_analog_low)
• Count rate in the low water vapor channel(water_counts_low)
• Summed analog signal in the low elastic channel(elastic_analog_low)
• Count rate in the low nitrogen channel(nitrogen_counts_low)
• Summed analog signal in the low nitrogen channel(nitrogen_analog_low)
• Count rate in the low elastic channel(elastic_counts_low)