MODAPS PCR 06-001

PCR Number 06-001
Date 2006-01-17
Initiator Liam Gumley
Abstract Multiple changes to L1B destriping algorithm.
Problem Statement There are 2 issues. Aqua band 27, detector 3 (product order) took a hit over the South Atlantic Anomaly (SAA) on day 2005-010 at approximately 17:15 GMT and has shown increased noise ever since. It should be replaced in the University of Wisconsin L1B destriping algorithm (MOD_PRDS) with a near neighbor.
The second issue is rare and involves the apparent successful completion of the destriping algorithm in cases where the configuration file is unreadable. New code logic and messaging are needed.
Description of Change A second destriping configuration file (v2) is used to replace detector 3 with a high quality neighbor after the epoch date 2005-010 17:15 GMT. Data processed prior to the SAA event use the original (v1) configuration file.
New code logic will exit and fail the L1B destriping algorithm if the configuration file is opened, but the header record is unreadable. Prior to exit, an error message is written to the LogStatus file and code.
Products Affected L2 Cloud Mask, Atmospheric Profiles, Cloud, and Clear Sky Radiance Products
Software Affected PGE03, PGE06, and PGE85
Processing String to Receive the Change Terra Forward, Terra Reprocessing, Aqua Forward, Aqua Reprocessing, GDAAC
Downstream Product Effects Both issues affect the Aqua stream. Terra may realize only rare instances when the configuration file cannot be read. The effects on Aqua include atmosphere L2 and L3 products and possibly Land PGEs that input CloudMask and Profiles.
Data Granules to be Used for Science Testing Run a complete one-day test on day 2005-010.
Justification Removal of striping in the Aqua band 27 detector 3 and potentially improved L2 through L3 products.
Effective Date for Implementation of Change  
Status Vincent Salomonsom approved on 04/03/06.