GHG measurements using an imaging FTS on a stratospheric balloon: a tech demo for the Arctic observing mission

The Arctic Observing Mission (AOM) is currently under mission concept study by the Government of Canada for potential implementation with prospective U.S. and European partners. It would use two satellites in a Highly Elliptical Orbit (HEO) to make geostationary-like observations of greenhouse gases (GHGs), air quality species of interest, meteorology, and space weather over northern regions. An imaging Fourier transform spectrometer (iFTS) has been selected as the technology for GHG observations. To elevate the technology readiness level of the iFTS, the Canadian Space Agency (CSA) has awarded contracts to Canadian industry and academia to advance the technology. An iFTS instrument suitable for sub-orbit demonstration has been built. Calibration techniques and software suites for processing the acquired iFTS image data have been developed. The CSA has flown the iFTS instrument in a stratospheric balloon campaign from its CSA-CNES Stratos Balloon Facility based in Timmins, Ontario, Canada to demonstrate its ability to measure GHGs over the boreal forest from an altitude of 37km. This paper briefly describes the development of the iFTS instrument and its adaptations to the stratospheric balloon platform for sub-orbital flight demonstration. The paper also reports instrument pre- and post-flight calibration, FTS image data processing techniques, retrieval of GHG data products and a brief analysis of these products. The balloon flight demonstration with a sub-optimal geometry and low cost iFTS prototype delivered GHG data products that met all expectations. This work not only elevated the technology readiness level of the iFTS technology, but also provided lessons that greatly benefit the development of the iFTS for the AOM mission.