Methane Conference 2019

Industrial Methane Measurement Conference 2019 - Abstract

Abstract Title: NIMCAM: a new instrument concept for observing atmospheric methane from a CubeSat platform
Presenter Name: Mr Jerome Woodwark
Co-authors:Prof Paul Palmer
Dr David Lee
Dr Damien Weidman
Company/Organisation: University of Edinburgh
Country: United Kingdom

Abstract Information :

Methane is a significant greenhouse gas, however recent variations and trends in atmospheric methane concentrations are poorly understood. Available satellite data on methane concentrations provide global coverage, but suffer from low resolution (several kilometres per pixel), often poor sensitivity to methane in the planetary boundary layer (PBL), and low temporal resolution. The Near Infrared Multispectral Camera for Atmospheric Methane (NIMCAM) is a proposed methane-specific instrument that aims to address these issues and improve the quality and quantity of methane concentration data. Design drivers for NIMCAM are: suitability for CubeSat deployment - compact, robust, low-power; good sensitivity to methane in the PBL; high spatial resolution; low cost. A low-cost instrument suitable for a CubeSat platform would enable a constellation deployment, substantially reducing re-visit intervals from days to hours. The instrument concept is based on an ultra-narrow-band multispectral imager operating in the near-infrared, with technology developments anticipated in areas including ultra-narrow-bandpass near-infrared filters with non-standard optical geometries, high-resolution near-infrared imaging arrays, and image acquisition and processing algorithms. Three 1nm bandpass filters located around 1640 nm provide three spectral channels, targeting retrieval of surface albedo, water vapour concentration, and methane concentration. A high resolution detector is used to provide a ground pixel size of the order of 100 metres across a 100 km swath width. Synchronising the imaging rate with the satellite ground track such that the surface image grid moves one pixel per frame interval enables several hundred co-additions to be made per pixel, significantly improving SNR. This poster will present outcomes from completed computer modelling of the instrument, and ongoing work to develop a laboratory demonstrator to prove out the engineering concept.