MODAPS PCR VNP 21-013

PCR Number VNP 21-013
Date 2021-08-17
Initiator Carol Davidson
Abstract PGE603 2.0.5 -- For all science changes, refer to section "Description of Change".
Problem Statement Corrected an Issue in the code where numpy causes an issue where scan and track values are incorrect in the output. Changes made within PGE603 v2.0.5. Installed to NRT3 for use starting 8/17/2021
Description of Change After updating the firelock code to a new python a bug was noted in the scan/track information for some of the output data.

The issue is that there was a bug in a calculation performed in the pixel_size_viirs() function where having unsigned and signed integer data types in the calculation leads to different results.

Changed scan, track = pixel_size_viirs(data['FP_sample'], \

data['prod750'])

To

scan, track = pixel_size_viirs(np.int32(data['FP_sample']), \

> data['prod750'])

Products Affected VNP14IMGT and VJ114IMGT
Software Affected PGE603 2.0.5
Processing String to Receive the Change NRT
Downstream Product Effects All VIIRS land products
Data Granules to be Used for Science Testing A science test was conducted, to confirm this new version of the "fireloc" code, by running it over one day period from nrt4
Justification This version contains a fix to the broken scan/track data appearing in the current production version.
Effective Date for Implementation of Change PGE603 v2.0.5 can be used for NRT SNPP AS5001 and JPSS1 AS5200 starting 8/17/2021; installed for use and start use as of 8/17/2021 data.
Status Major algorithm development completed. Sadashiva Devadiga approved 08/18/2021. Gang Ye approved on 08/20/2021.