SCIENTIFIC ASSESSMENT OF TDS-1 GNSS-R SCATTEROMETRIC MEASUREMENTS
5, August 2015

ESA Open Invitation To Tender AO8365
Open Date: 31/07/2015
Closing Date: 19/09/2015

Status: ISSUED
Reference Nr.: 15.155.10
Prog. Ref.: EOEP-4 EO Prep. Acti
Budget Ref.: E/0092-E4 – EOEP-4 EO Prep. Acti
Special Prov.: BE+DK+FR+DE+IT+NL+ES+SE+CH+GB+IE+AT+NO+FI+PT+LU+CZ+CA+PL+RO
Tender Type: C
Price Range: 200-500 KEURO
Establishment: ESTEC
Directorate: Directorate of EO Programmes
Department: Science, Appl & Future Technologies Dept
Division: Future Missions Division
Contract Officer: Tchoualack, Cendrine
Last Update Date: 31/07/2015
Update Reason: Tender issue

The need for more extensive and reliable monitoring of sea state (wind, waves) is widely recognised. One very attractive and cost-effective way with high revisit time, is to make use of reflected GNSS signals of opportunity to acquire relevant scatterometric information. TechDemoSat-1 (TDS-1) is an SSTL small satellite (150 kg), funded nationally and launched in July 2014. One of its most complex payloads is the Sea State Payload (SSP), which is a GNSS-Reflectometry (GNSS-R) scatterometry payload to derive sea state andwind speed, with substantial improvements with respect to UK DMC launched in 2003. ESA has supported SSTL (UK) and NOC (UK) to dothe commissioning of the SSP instrument in TDS-1, including the data acquisition planning, algorithms for the generation of new Level2 fast-delivery inversion for wind speed and mean-square-slope. The first results and analyses are very positive, but additionalwork is needed. There is a strong interest by the user community in analysing larger data sets, like the unique ones from TDS-1,in order to compare, validate and refine inversion models and to derive the information that would support the deployment of a future (pre) operational capability. In addition to the Fast Delivery retrieval algorithms – under development by SSTL and NOC – that must comply with strict timeliness requirements, there is a need to develop science products that are more complete and more accurate. Thekey objective of this study is, based on the analysis of TDS-1 data and supported by adequate simulation tools, to quantitatively and unambiguously relate the GNSS-R observables to some geophysical characteristics of the sea surface, in order to support the inversion of these observables and/or their assimilation into observation systems. The focus shall be put on TDS-1 Delayed Mode Level-2 products such as consolidated wind speed and wind direction, directional mean square slope, and other products. For each producta solid error model shall also be developed. The activity is in open competition, but a limited part of the work will be directly assigned to NOC and SSTL in order to ensure adequate support to the bidding consortia.

If you wish to access the documents related to the Invitation to Tender, you have to log in to the ESA Portal.