Nov. 1, 2008

Purpose: investigate the offset between analog and photoncounting (PC) data.
We already knew there is a offset between analog and PC data. We want to make sure this offset is not variable with range.

1. Look at channel-5 where the gate is turned on for analog and PC channel-5. The offset is 1985-1949=36m at 2-km altitude.

2.Look at clouds. Offset=1888-1850=38m

3. Look at the cloud feature at far range. Offset=9640-9605=35m. So basically the offset,~35-40m~10bin, is constant with time.