The Envisat satellite has an ambitious and innovative payload that will ensure the continuity of the data measurements of the ESA ERS satellites. Envisat data supports earth science research and allows monitoring of the evolution of environmental and climatic changes. Furthermore, the data will facilitate the development of operational and commercial applications.
ASAR (Advanced Synthetic Aperture Radar)
An Advanced Synthetic Aperture Radar (ASAR), operating at C-band, ASAR ensures continuity with the image mode (SAR) and the wave mode of the ERS-1/2 AMI. It features enhanced capability in terms of coverage, range of incidence angles, polarisation, and modes of operation. This enhanced capability is provided by significant differences in the instrument design: a full active array antenna equipped with distributed transmit/receive modules which provides distinct transmit and receive beams, a digital waveform generation for pulse "chirp" generation, a block adaptive quantisation scheme, and a ScanSAR mode of operation by beam scanning in elevation.
DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite)
DORIS is a tracking system providing range-rate measurements of signals from a dense network of ground-based beacons. These data are precision processed on ground providing the satellite orbit with an accuracy of the order of centimetres.
They are also processed on board to provide real time satellite positions with an accuracy of some tens of centimeters. In addition to enabling orbit determination, data are provided to:
help in the understanding of the dynamics of the solid Earth;
monitor glaciers, landslides and volcanoes;
improve the modeling of the Earth gravity field and of the ionosphere.
 |
1/3 |  |