Sample Results Addressing PIF 990330.3

1/22/01
Karen Johnson

Sample Files Processed

I've run the following 9 sample Raman lidar data files through an IDL script for fixing the height offsets in the four affected time periods:

sgprlC1.a0.19971006.000022.cdf
sgprlC1.a0.19981001.000055.cdf
sgprlC1.a0.19981009.000010.cdf
sgprlC1.a0.19981022.000039.cdf
sgprlC1.a0.19981028.000010.cdf
sgprlC1.a0.980221.000014.cdf
sgprlC1.a0.980628.000004.cdf
sgprlC1.a0.990125.000041.cdf
sgprlC1.a0.990421.000051.cdf

Four of these files were selected by the script as needing correction and were corrected as follows

sgprlC1.a0.19971006.000022.cdf

For all channels, shift bins such that bin 66 occurs at bin 65
sgprlC1.a0.980221.000014.cdf
For water_counts_high and water_counts_low channels,  shift bins such that bin 66 occurs at bin 65.
sgprlC1.a0.980628.000004.cdf
For water_counts_low channel, shift bins such that bin 66 occurs at bin 65.
sgprlC1.a0.990125.000041.cdf
For all channels, shift bins such that bin 69 occurs at bin 65.
In all cases, the lowest five bins (0 - 4) and the highest five bins (794-799 for high channels and 294-299 for low channels) were not moved due to possible spikes.
 

Corrected Sample Files Available

I've placed "gzip'd" versions of the corrected sample files on our ftp site for retrieval if you'd like to look at them.  The files are available via anonymous ftp from ftp.ccd.bnl.gov.  The files are

incoming/sgprlC1.a0.980221.000014.cdf.gz
incoming/sgprlC1.a0.980221.000014.cdf.gz
incoming/sgprlC1.a0.980628.000004.cdf.gz
incoming/sgprlC1.a0.990125.000041.cdf.gz
 

"Before and After" Plots

I've plotted portions of some "before and after" fields:

Each plot shows high or low channel water vapor counts vs. bins 55 - 75 at the time indicated in the plot title. In each plot, the solid line shows the original values.  The dashed line shows the result of the bin shifting.

Here are the same plots, only showing all bins:

On this scale, is difficult pick out the dashed and solid lines.  However, all the fields look reasonable, before and after correction.