Geostationary Environment Monitoring Spectrometer
GEO-KOMPSAT 2-B will fly GEMS and GOCI, an ocean color imager. Image credit: NASA
Ball Aerospace is building the Geostationary Environment Monitoring Spectrometer (GEMS) under a commercial contract with the Korea Aerospace Research Institute (KARI) for the National Institute of Environmental Research in the Ministry of Environment of South Korea. GEMS will fly on KARI’s GEO-KOMPSAT-2B geostationary satellite and is scheduled for a 2018 launch.
GEMS is a geostationary scanning ultraviolet-visible spectrometer designed to monitor trans-boundary pollution events for the Korean peninsula and Asia-Pacific region. The spectrometer provides high spatial and high temporal resolution measurements of ozone, its precursors, and aerosols. Hourly measurements by GEMS will improve early warnings for potentially dangerous pollution events and monitor long-term climate change.
Early stage GEMS instrument
Ball Aerospace and KARI will design, fabricate and test GEMS. Ball and KARI engineers are working together on Ball’s Boulder campus as part of a joint development project to build the GEMS sensor.
The GEMS instrument has a 2-axis scan mirror and a 1k x 1k focal plane array using a Charge Coupled Device (CCD) to image the ultraviolet/visible spectrum. GEMS will scan a 5000 km East/ West area in less than 30 minutes with state-of-the-art calibration and high spatial and spectral resolution. In geostationary orbit at 35, 786 km (22,236 miles) above the Earth, GEMS will collect images over an 8 to 12 hour period.
The GEMS instrument is the Asian element of a global air quality monitoring constellation of geostationary satellites that includes the Tropospheric Emissions: Monitoring of Pollution (TEMPO) spectrometer. Ball is the TEMPO instrument provider for NASA Langley Research Center and Harvard Smithsonian Astrophysical Observatory. Both GEMS and TEMPO leverage the company’s expertise and technology developed for previous ultraviolet-visible instruments.
For more than 30 years, Ball Aerospace has been a recognized industry leader in developing advanced spectrometers. Ball recently provided the Ozone Mapping and Profiler Suite aboard the Suomi National Polar-orbiting Partnership and is building a similar instrument for the Joint Polar Satellite System spacecraft JPSS-1. Historically, Ball was the primary supplier of spectrometers for the Hubble Space Telescope including the Goddard High Resolution Spectrograph, Space Telescope Imaging Spectrograph, and the Cosmic Origins Spectrograph.
Ball GEMS Program Manager Chris Randall interviewed on KBS-TV