GMES Sentinel-1 Mission and Products
Evert Attema(1), Paul Snoeij(1), Malcolm Davidson(1), Nicolas Floury(1), Betlem Rosich(2), Bjorn Rommen(1) and Guido Levrini(1)
(1) ESA, Keplerlaan 1, 2200 AG Noordwijk, Netherlands
(2) ESA, Via Galileo Galilei, 00044 Frascati, Italy
Sentinel-1 is a dual polarisation imaging radar mission at C-band consisting of a constellation of two satellites aimed at providing continuity of all-weather day-and-night supply of imagery for user services. Special emphasis is placed on services identified in ESA’s GMES service elements programme and on projects funded by the European Union Framework Programmes. Three priorities (fast-track services) for the mission have been identified by user consultation working groups of the European Union: Marine Core Services, Land Monitoring and Emergency Services.
Sentinel-1 data products need to maintain data quality levels of the Agency‘s previous SAR missions in terms of spatial resolution, sensitivity, accuracy, polarisation and wavelength. Feedback from users following the consolidation phase of the GMES services indicate unambiguously that the crucial requirements for operational sustainable services are continuity of data supply, frequent revisit, geographical coverage and timeliness. Compared to the current satellites in orbit substantial improvements of data provision in terms of revisit frequency, coverage, timeliness and reliability of service would be required. As an example, services related to ocean and sea ice encompassing ship and oil spill detection, wind speed measurements and sea ice monitoring require frequent revisit (once per day, mostly at northern latitudes) and timeliness (near-real-time delivery of data within one hour of acquisition). Services related to land encompassing interferometry and land cover classification mostly require global coverage every two weeks at most and consistent data sets that are suitable for interferometry.
Sentinel-1 is designed to work largely in a pre-programmed conflict-free operation imaging all global landmasses, coastal zones, shipping routes in full resolution and covering the global ocean with imagettes. Dual polarisation and interferometric applications are served by the frequent revisit in combination with the stringent requirements on the orbit maintenance and knowledge.
This paper describes the Sentinel-1 mission. It provides an overview of the system implementation. Requirements and constraints for the mission operations will be discussed. The relation between the accuracy of a number of key user information products such as ice type classification, ship detection, land surface movement measurement on the one hand and typical system requirements on engineering parameters such as spatial resolution, sensitivity, radiometric resolution, and calibration accuracy will be introduced.