Comparing Spectro-radiometer Instruments for a Satellite Mission to Detect Chemical Warfare Agents

Previous research has indicated that it is theoretically possible to detect chemical warfare agents, such as sarin and sulphur mustard from space. However, this analysis showed that limitations with spatial resolution mean that the likelihood of realtime detection of chemical warfare agents was low. This leads to this idea for a satellite mission that could achieve this capability. Such a mission would be of value both to the monitoring of chemical releases and to emergency services in responding rapidly to incidents and attacks, especially in remote and inaccessible areas. In this paper, three potential instruments are compared in a trade study, against the Infrared Atmospheric Sounding Interferometer (IASI) instrument on ESA's MetOp satellite as a benchmark. Operational scenarios in which a potential future mission would operate are used to derive requirements on the instruments. First is a Laser Heterodyne Radiometer (LHR), second is the Tropospheric Emission Spectrometer (TES), a spectrometer flown on NASA's AURA mission, and last is the High-resolution Anthropogenic Pollution Imager (HAPI). The instruments' parameters such as spatial, spectral, and temporal resolutions as well as revisit time and instrument needs such as Size, Weight and Power (SWaP) were compared against the mission requirements. It was determined that no single instrument was able to meet all of the operational requirements alone, indicating that combinations of instruments may be necessary to produce a mission that can fulfil the requirements, with two basic concepts suggested for further research.