ERS 1/2 - Envisat ASAR
Cost effective SAR solutions
The European Space Agency (ESA) chose the SARCOM consortium as worldwide distributor of the products derived from the data acquired by the ERS, Envisat satellites. SARCOM is a group of 8 international stakeholders in the Earth observation market, all specialists in applications derived from SAR imagery.
Alternating Polarisation Mode
Envisat satellite image © ESA 2002
Characteristics
The Envisat satellite was launched in 2002 as a follow-on to ERS-1 (1990-2000) and ERS-2 (1995-2011). These 3 satellites have C-band.
The ERS satellites acquired radar images at a fixed angle of 23° while Envisat has a pointable imaging instrument enabling weekly coverage at the equator and daily coverage over the poles.
Products
A 20-year archive is available from both ERS-1 and ERS-2 mission, including interferometric pairs from tandem acquisitions campaigns.
Envisat satellite offers the following acquisition modes:
- Image mode: with a resolution of 25 m and covering a surface area from 56 to 100 km by 100 km, it is a follow-on for ERS products
- Alternating Polarisation mode: with same resolution and coverage than Image mode, it offers dual polarisations images
- Wide Swath mode: it supplies medium resolution products (150m), covering a surface area of 400 km x 400 km.
Envisat satellite image - Reunion Island
© ESA 2003
| Acquisition modes | Satellite | Applications |
|---|---|---|
| Image (IM) | ERS Envisat |
Topographical & geologyical mapping, Ice/Snow, surface movement, mineral and petroleum prospecting |
| Alternating Polarisation (AP) | Envisat | Agriculture, forestry, hydrology and land cover |
| Wide Swath (WS) | Envisat | Flood extend, soil moisture, oceanography, ship detection, icebergs monitoring and marine pollution |
ERS Envisat satellite image
Pollution by the tanker Prestige
© ESA 2002
| Processing level | Characteristics | For which processing? |
|---|---|---|
| Raw | Raw data with ancillary data | Image synthesis, interferometry |
| SLC (Single Look Complex Image) | Single look image with complex format (amplitude, phase) | Amplitude and phase calculation Interferometry |
| PRI (Precision Image) | 3-look amplitude image with radiometric correction | Quantitative analyses, photo-interpretation and image processing. |
| GEC (Ellipsoid Geocoded Image) | 3-look amplitude image with radiometric correction and georeferenced (WGS84) without ground control points | Photo-interpretation, image processing, multidate/multisource overlay |
| MRI (Medium Resolution Image) | Multi-look amplitude image with radiometric correction | Near real-time monitoring and control (ship detection, pollution monitoring, etc.) |
See Also...
