GeoXO Atmospheric Composition Instrument (ACX) Architecture, Performance, and Calibration

NOAA’s Geostationary Extended Observations (GeoXO) mission extends and expands Earth observations provided by the GOES-R system. The recommended GeoXO constellation contains a GEO-Central observatory with an Atmospheric Composition instrument (ACX). Mission observables are aligned with many NOAA application forecasting and monitoring areas such as air quality, hazards, weather & climate, and secondary pollutants. The ACX mission also measures multiple designated observables included in the National Academies of Sciences Decadal Survey for Earth Science and Applications from Space (ESAS 2017). The Tropospheric Emissions: Monitoring of Pollution Instrument (TEMPO) launched on April 7, 2023 and has Level1b data publicly available with similar observable objectives. The high spatial and temporal resolution of these instruments allow for measurements and analyses of the complex diurnal cycle of pollution, driven by the combination of photochemistry, chemical composition, and the dynamic nature of the atmosphere. BAE’s ACX instrument leverages significant design heritage from TEMPO and The Geostationary Environment Monitoring Spectrometer (GEMS) and will use both instruments as pathfinders for the ACX mission which will not launch until the mid-2030s. BAE applies lessons learned from these programs to improve performance and “operationalize” the ACX design. GEMS and TEMPO were developed and manufactured in parallel and share a common design, capability, and calibration strategy. We leverage this commonality and heritage for a proposed instrument concept for the National Oceanic & Atmospheric Administration, GeoXO Atmospheric Composition Instrument (ACX). Here we discuss proposed changes and improvements to the TEMPO/GEMS design for accommodating the ACX mission and science requirements.