The era of Landsat satellites started in 1973 with the launch of the first MSS satellite. Since then, the specifications of the Landsat satellites have improved and data from the ETM+ sensor on Landsat 7 and the OLI sensor on Landsat 8 provides 15 m panchromatic data and 30 m multispectral data. A huge archive of data is available, making Landsat an ideal and cost-effective choice in change detection applications.
The ASTER sensor onboard the Terra satellite provides data at various resolutions from 15 metres to 90 metres. It is capable of producing Digital Elevation Models due to the telescope's backward viewing band for high-resolution along-track stereoscopic observation. ASTER has several thermal infra-red bands that are well suited for vegetation, climate and geological applications. Data is available since 1999.
Various SPOT sensors are currently in orbit with spatial resolutions from 20 metres down to 1.5 metres. The SPOT archive dates back to 1981 when SPOT-1 was launched and this makes SPOT an ideal solution for time series analysis. SPOT data at 20 metre resolution are a cost-effective solution for land cover mapping, agricultural applications and change detection due to the long history of SPOT satellite acquisitions.
The primary objective of the IRS satellites is to provide systematic and repetitive acquisition of data of the Earth’s surface under nearly constant illumination conditions. The IRS satellites provide 5 m panchromatic imagery and 23 m multispectral imagery as well as large swath imagery at a spatial resolution of 188 m.
The Deimos-1 is a private Spanish earth imaging satellite that provides data for terrestrial vegetation studies with a good temporal resolution. Overall a cost-effective solution for land cover mapping and agricultural applications.