1. Investigation of NCC EDR Issues: Path Forward
August 22, 2012
Steve Mills & Calvin Liang
NGAS A&DP

2. NCC EDR Issues
Problem: Currently the near-constant contrast (NCC) imagery EDR does not produce imagery for all solar and lunar conditions.
This is expected for night conditions where both the solar and lunar zenith angles exceed 105 degrees
The outages, however, are more extensive than this, and it is not clear why.
Issue at hand is that either:
NCC is not produced for all lunar and solar conditions where it should because of some logic limitation
or NCC is saturated for many of the lunar conditions because of stray light in the scene itself or in the data used to generate the LUT.
This is just a chart outlining the parameter space and I investigate and how I did the investigation

3. Path Forward to Investigate NCC EDR Issues
Proposed steps to investigate NCC issue:
Collect SVDNB, GDNBO, and IVOBC granules from August 16-17th, 2012 – Around new moon
Construct stray light correction lookup table (LUT) from new moon data.
Apply stray light correction LUT to new moon granules using NGAS stray light correction algorithm
Determine best functional fit to corrected radiances and account for night glow.
Produce a new GVVSSE/GVVSLE LUT based on the new functional fits.
Remove stray light in problematic granules.
Run the latest version of the NCC EDR algorithm in ADL on stray light corrected granules.
Inspect output to determine whether some of the problems identified in the granules go away with stray light correction.
If it is found that fixing stray light does not completely solve the problems, then we will delve into the NCC EDR algorithm logic.
This is just a chart outlining the parameter space and I investigate and how I did the investigation