MODAPS PCR 21-020
| PCR Number | 21-020 |
|---|---|
| Date | 2021-07-13 |
| Initiator | Sudipta Sarkar |
| Abstract | PGE103 V6.1.2 -- For all science changes, refer to section 8 above. In addition, the following are to be noted: 1. New version of code in python2/3. 2. Adds header to output file: "latitude,longitude,Mid-IR,scan,track,acq_date,acq_time,satellite,confidence,version,Long-IR,frp,daynight". 3. Header only files are deleted in the COMB/PGE603.pl file by checking m5sum and file size. 4. Added code to fireloc2.py to deal with inconsistent handling of single element arrays. i.e., the error that we see in scan/track when there is only one fire pixel entry in the input files. |
| Problem Statement | Replace the existing different variations of the MODIS/VIIRS fire location code ("fireloc") with a single and uniform code, across all sensors and platforms, with consistent algorithm parameters and some other improvements. |
| Description of Change | At present, the different variations of the "fireloc" use the following inconsistent definitions of day and night to set the text-file day/night field: i) Day/night algorithm mode, which is determined using an 85° solar zenith angle threshold for MODIS and VNP14, and a 90° solar zenith angle threshold for VNP14IMG. ii) Sunrise/sunset using a 90° solar zenith angle threshold. iii) Ascending/descending orbit phase as implemented in the MODIS fireloc code. The new "fireloc" code sets the day/night field for all products consistently using the sunrise/sunset criterion, i.e., definition (ii) above. In addition, it has the following improvement over the current variations: 1. Change fire acquisition time from granule start times to the nearest minute, to provide more precise times. 2. Make code flexible enough to handle granules of arbitrary length. 3. Change certain global attribute naming scheme. |
| Products Affected | Daily C61 MOD14T/MYD14T |
| Software Affected | PGE103 V6.1.2 |
| Processing String to Receive the Change | Terra and Aqua Forward Processing. NRT. |
| Downstream Product Effects | None |
| 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 an extended period from nrt4. |
| Justification | Replace the multiple different sensor specific variations of this code, with different thresholds and criteria, with one single consistent version that can accept inputs from different sensors, in different formats and with granules of different sizes. This new version also moves away from C to Python and carries some additional improvements related to the fire acquisition time. |
| Effective Date for Implementation of Change | C61 specific PGE103 V6.1.2 can be made operational from STD and NRT, starting 07/15/2021. |
| Status | Major algorithm development completed. Sadashiva Devadiga approved on 07/13/2021. Chris Justice approved 07/14/2021. Gang Ye approved on 07/14/2021. |
