The Sentinel-1 Constellation Evert Attema, Sentinel-1 Mission & System Manager AGRISAR and EAGLE Campaigns Final Workshop 15-16 October 2007 ESA/ESTECNoordwijk, The Netherlands
Sentinel-1 Programme Sentinel-1 System Sentinel-1 Information Products
Programme Status
Sentinel-1 Programme Status Component of EU & ESA s Global Monitoring for Environment and Security Programme (GMES) Contract signed for development, launch and commissioning First Satellite launch Q4 2011 Services provided for 20 years 2008 2010 2012 2014 1st S1 Dev LC 2nd S1 Dev 3rd S1 Dev LC LC 3rd model launched in case of launcher failure Storage
Sentinel-1 Mission Requirements Goal Provide Coverage and Repeat Observation to Completely Cover on a Daily Basis the world s land masses; coastal zones and shipping routes; open ocean. Requirements Sufficient Instrument Resources in terms of Temporal Coverage: Short Orbit Repeat Cycle Spatial Coverage: Wide Swath Operation Time per Orbit Pre-programmed Conflict-free Acquisition Plan Restricted Choice of Mutually-Exclusive Measurement Modes Sufficient Ground Segment Resources in terms of Satellite Control and Orbit Maintenance Data Down-link Capacity Processing, Distribution & Archiving Capacity
System Update
Sentinel-1 System Sentinel-1 has one main operational mode (Interferometric Wide Swath mode) that: satisfies most currently known service requirements avoids conflicts and preserves revisit performance provides robustness and reliability of service simplifies mission planning & decreases operational costs satisfies also tomorrow s requests by building up a consistent long-term archive However Mutually exclusive modes are provided for continuity reasons (w.r.t. ERS & Envisat) and for accommodation of emerging user requirements Two mutually exclusive dual polarisation modes are provided
Sentinel-1 System Modes Access Angle Resolution (Range x Azimuth) Swath Width Polarisation Strip Map 20-45 deg. 5 x 5 m, 1 look > 80 km HH+HV, VV+VH Interferometric Wide Swath > 25 deg. 5 x 20 m, 1 look > 250 km HH+HV, VV+VH Extra Wide Swath > 20 deg. 25 x 100 m, 3 looks > 400 km HH+HV, VV+VH Wave mode 23 deg. 5 x 20 m, 1 look > 20 x 20 km Vignettes at 100 km intervals HH, VV For All Modes: Radiometric accuracy (3 σ): 1 db NESZ: -22 db PTAR: -25 db DTAR: -22 db
Observation Geometry
Space Segment Sentinel-1 System LEO satellite with a nominal lifetime in orbit of 7 years (extendible to 12), ensuring global coverage by flying on a Near-Polar Sun- Synchronous dusk-dawn Low Earth Orbit. A constellation with a second satellite is planned in the same orbit but with a different Mean Anomaly. The satellites embark a C-Band Synthetic Aperture Radar (SAR) payload. Ground Segment Mission operations for a system of satellites over a period of 20 years. Proposed S-Band station is Kiruna, with a back-up for S/C contingencies. The X-Band downlink currently assumes, for preliminary sizing, three X-Band receiving stations.
Sentinel-1 Timeliness Near Real Time (inside Ground Station Visibility) Data from Reception to End-Users in less than one hour
Sentinel-1 Timeliness Near Real Time (outside Ground Station Visibility) ~ 90 GByte/orbit Up to ~ 100 minutes travel in orbit Data from Reception to End- Users in less than one hour
Sentinel-1 Timeliness Off Line All data processed, archived and ready for use in less than 24 hours from reception
Sentinel-1 Revisit Coverage Analysis Coverage with two satellites after 23 45 61 days Canada Europe
Coverage of Areas of Interest
Simplified impossible Mission Scenario
Information Products
Information Product (1) Monthly Soil Moisture
Information Product (2) Daily Ice Monitoring
Snow Cover Algorithm (SCA) Algorithm developed and validated by NORUT (ESA contract 19629/05/NL/CB ) Algorithm based on image intensity differences combined with suitable thresholds (2000, Nagler & Rott) Analysis of SAR sensitivity was therefore performed on the basis of real data and simulated noise Level-1 Data Black Box Algorithm Thresholds Simulated Noise
Subsidence Estimation [mm/year] Barcelona (Spain) Envisat ASAR 5 images [2003-2004]