EO-Sat1
EO-Sat1 is a high performance Earth-Observation satellite designed to produce data for a broad range of Earth observation applications. The satellite features two imaging payloads – one narrow angle, high resolution and one wide angle, medium resolution – capable of providing true diffraction limited imagery from 2.5 1.8m GSD and 30 22km swath, to 60 m GSD and 184 0km swath. Both instruments cover the same 10 spectral bands in the visible to near-infrared spectrum. An agile, fully dual-redundant bus allows imaging in continuous nadir coverage, spot and stereoscopic modes. EO‑Sat1 is ideally sized for launching in quantities of three to five, significantly improving the economy of deploying a constellation for increased imaging coverage and reduced revisit intervals.
Applications
The unique combination of high resolution and medium resolution instruments, both imaging in the same 10 spectral bands, cater for a broad range of applications, including:
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Monitoring the state and evolution of vegetation in agricultural lands and forests (MedRes)
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Detailed land cover mapping (MedRes & HiRes)
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Monitoring built environment and in particular human settlements (HiRes)
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Disaster management (HiRes)
EO-Sat1 data is processed to Level 1B (band aligned and radiometrically calibrated), and delivered in standard GeoTIFF format.
Payload
EO-Sat1 carries two imaging instruments: a high resolution (HiRes) and a medium resolution (MedRes) instrument. The HiRes consists of a modified Ritchey-Chrétien astrograph front end, while the MedRes consists of a Double Gauss refractive front end. Both instruments provide large focal planes and low optical aberrations, while delivering true diffraction limited performance over the full spectral range from 400 to 930 nm. Two identical sets of Time Delayed Integration (TDI) capable sensors provide 10 spectral bands for each instrument. The number of TDI stages are in-flight configurable to allow optimisation of the dynamic range and signal to noise ratio per band.
The HiRes swath of 30km is centred within the MedRes swath, and the of 180km. The two instruments can be operated simultaneously or separately.
In a lower orbit, that EO-Sat1 will gain GSD at the cost of swath. At 500 km, for example, the HiRes has GSDs of 1.8 and 7.2 m with a swath of 22 km, while the MedRes has GSDs of 11 and 43 m with a swath of 131 km.
