Low Cost Hyperspectral Imaging From a Microsatellite

A 100 kg class SSTL microsatellite platform accommodating the Sira Compact High Resolution Imaging Spectrometer (CHRIS) can perform high spectral resolution imaging over multiple wavelengths. Hyperspectral imaging data may be used within a wide variety of applications ranging from precision agriculture and land use, to ocean colour monitoring, coastal and atmospheric studies. CHRIS operates in the 415 to 1050 nm wavelength band, with spectral sampling interval from 2 to 12 nm (depending on wavelength) and is programmable from the ground. Operating at 25 m ground sample distance the instrument can provide information over 19 spectral bands whilst at 50 m ground sample distance, for example, 63 bands can be imaged simultaneously. Flying CHRIS as the main payload on a SSTL microsatellite enables dedicated platform resources to exploit the huge potential of such a payload at low cost. The three-axis stabilised platform can off-point from nadir by ±30° to support accurate target selection. 48 Mbps payload data downlink rates, a 12 Gbyte data storage, and high efficiency GaAs panels for power provision all ensure a good payload duty cycle per orbit. The estimated spacecraft cost is 8.5 million GBP, resulting in affordable constellation options. A constellation of hyperspectral satellites providing high temporal resolution in addition to high spectral resolution could also be used to enhance the infrastructure of the Disaster Monitoring Constellation (DMC). The DMC is currently under construction at SSTL and is due for launch in 2002. This may be implemented either singly, or in constellations, via a ‘plug and play’ constellation approach. This paper describes how low cost hyperspectral imaging may be effectively accomplished using a microsatellite platform and looks at the potential benefits of implementing a series of these microsatellites in a constellation