ERS-1, 2 satellite imagery

ERS had been developed by the European Space Agency beginning with the early 80s of the previous century. ERS-1 was launched into sun-synchronous orbit with an average altitude of 785 km and 98.5 deg inclination on July 17, 1991. ERS-2 was launched into the same orbit on April 21, 1995 serving as the successor and constructive analogue of ERS-1. ERS-1 was equipped with 5 and ERS-2 with 6 various remote sensing devices including optical UV and IR scanners, radar altimeter, etc. However taking into account ultralow spatial resolution of the instruments, users are mostly interested in synthetic aperture side-viewing radar SAR, imaging the Earth in the C-band, 5.6 wavelength, vertical polarization VV, 20 - 26° angular range. Estimated lifetime of ERS-1 was 3 years but the satellite was successfully operated up to March 10, 2000 which enabled ESA to use the satellite constellation for 5 years providing doubled frequency of the Earth remote sensing. A number of radar interferometry experiments was held as well including ERS Tandem in 1995 - 1996 which significantly improved the radar remote sensing technologies. ERS-2 active life was considered as 2 years however regardless minor failures the satellite was in orbit up to June 2003. Since that moment due to recording system breakdown the survey is provided only within the range of ESA ground stations.

ERS-1, 2 satellite imagery applications

• DEM and DSM high resolution creation (up to 5-10 meters height accuracy)
• Ice and snow assessment at the Sub-Arctic regions.
• Observing natural hazards (floods, ice movements, etc.) regardless of weather and time.
• Crop monitoring - mapping of the plants, yield assesment, crop condition, land use control.
• Forest monitoring - mapping of the forest grade, planting condition, loogings, etc.
• Creation and refreshing of topographical maps and special plans up to 1:200 000 scale
• Investigating and analysis of earth cantimetr movements by interferometer methods (under ERS Tandem project).