In its nominal operation, the Envisat Radar Altimeter (RA-2) provides waveforms at the rate of 18 Hz in KU band. It also has the capability of dumping to the ground, individual echoes in Ku band at 2000 Hz. These echoes are used to build up RA-2 waveforms. This unique feature of RA-2 offers the possibility to assess further the full potential and capabilities of altimeter measurements. To understand what can be expected technically and scientifically from this source of information, ESA has set up the RAIES study. The objective of the study is to undertake the development of a prototype processor to reconstruct these individual echoes, and to make use of these echoes in scientific applications as well as to exploit the S band data for scientific experiments.

CLS has been responsible for:

This study is performed by a consortium led by CLS and consists of a total of five companies and institutes from three European countries, which are in alphabetical order: CLS (Collecte Localisation Satellites), IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer), LEGOS (Laboratoire d'Etudes Géophysiques et Océan Spatiale), Pildo Labs and University College London (UCL).More specifically, CLS is involved in several tasks:

Project management:

• CLS is in charge of the study management, and acts as the coordinator. CLS is the formal interface to/from ESA with respect to this study, providing a single point of contact between the consortium and ESA.

• CLS will develop part of the prototype processor which will reconstruct RA-2 individual echoes. The other part is developed by Pildo Labs. CLS will also analyse the individual echoes reconstruction algorithm document to provide comments and a definition of the Individual Echoes from RA-2 (IE) product.
• CLS will test and validate the integrated software at contractor's site, and then will deliver and install it at the Agency's premises.
• Finally using the prototype, significant IE data set will be produced by CLS for use in scientific application.

• CLS is also involved in the scientific applications using IE Ku band and S band data.

Users:

ESA is the main customer.