On June 29, 2021, at 12:20:45z, printed wire assembly (PWA) #47 of the Terra spacecraft buffer failed. This PWA was allocated to the MODIS instrument. Because of this failure, the onboard data storage for MODIS science data has been reduced. On July 2nd, MODIS IOT performed tests on reducing the Terra MODIS data rate to accommodate this change. Starting July 3 at 20:00:00z, the tests were completed, and the data rate continued at the pre-PWA failure schedule, which began on May 2, 2021.
After several months of reviewing the performance of the Terra day/night-rate schedule (originally implemented November 8, 2020) and with input from science-team users, MCST has implemented a revised day/night schedule that goes into effect May 2, 2021 (2021/122). This updated schedule improves the day-rate data coverage by using a timing variation based on sun-angle changes throughout the year.
The MODIS and VIIRS Characterization Support Teams held a 2-day virtual calibration workshop on February 25 and 26, 2021 via MSTeams. The presentations from the workshop are posted here: https://modis.gsfc.nasa.gov/sci_team/meetings/202102/presentations.php
Due to the recent PWA failure on the EOS Terra spacecraft, MODIS has a reduced on-board memory allocation. Initial efforts reduced the data rate of day mode data (reflective solar band measurements) near the poles in a uniform manner. In an attempt to provide near-global two-day coverage, an alternating schedule was implemented starting November 8, 2020 (2020/313).
MODIS Characterization Support Team
The MODIS Characterization Support Team (MCST) is dedicated to the production of a high quality MODIS calibration product. This product is a precursor to every geophysical science product. MCST works for the Science Team Leader and is responsible for developing and maintaining the calibration product (L1B algorithm).
Collection 6 has been under development for a number of years. MCST, in consultation with representatives of the science disciplines, developed improvements to the calibration algorithms and methodolgies to handle known issues with the aging MODIS sensors. Summary talks of the proposed Collection 6 changes have been delivered at the MODIS science team meetings over the last few years.