Ben Gurion University

1. Ben Gurion University The VENμS mission: Earth Observation with High Spatial and Temporal Resolution Capabilities G. Dedieu1, O. Hagolle2, A. Karnieli3, S. Cherchali2 P. Ferrier2 and Y. Yaniv4 1 CESBIO, Toulouse Cedex 9, France 2 CNES Toulouse France 3 The Remote Sensing Laboratory, Ben Gurion Univ. of the Negev, Israel 4 MBT Space Division, Israel Aircraft Industries ISRAEL Mission scientists (PI's) : Gérard Dedieu & Arnon Kanieli

2. VENmS • VENmS is an Earth observation scientific mission jointly developed by CNES, the French space agency, and ISA, the Israeli Space Agency • Objectives : • To provide data for research on land surface functioning : land cover & land use, water and carbon exchanges, snow • Data assimilation • Automatic land cover mapping • Validation of medium resolution satellite products • Demonstration of the use of RS data for the implementation of Environmental regulations (e.g. Grenelle laws in France) • To investigate and demonstrate the benefit for Earth sciences and applications of highrepetitivity, highresolution remotely sensed measurements acquired by a superspectral imaging radiometer • To develop and experiment a dedicated ground segment able to deliver state of the art quality products

3. Why high temporal repetitivity ? June 5th 2006 June 14th 2006 June 23th 2006 June 29th 2006 Formosat-2 images (rapeseed harvest, sunflower growth)

4. Indice foliaire 2006

5. VENmS Uniqueness - Summary • Temporal resolution • 2 days revisit time for monitoring rapid changes : objective of a cloud free (composite) image every 7 or 10 days • Spectral resolution • Super spectral sensor – 12 spectral bands VIS-NIR for land applications • Spatial resolution • Pixel size of 5.3 m for Level 1, 10m for level 2 and 3. Registration requirement: 3 m rmse • Tilting capability • 30 deg across and along track • View angle • Constant view angle can be achieved every 2 days, at constant local solar time • Stereo pairs with a small angle difference at 620nm Cloud screening based on altitude, DEM generation

6. Vens Orbits Sun-synchronic LST : 10h30 Altitude: 720 km Inclination: 98.27° DAY 1, 3, 5, 7 …

7. Vens Orbits Sun-synchronic LST : 10h30 Altitude: 720 km Inclination: 98.27° DAY 2, 4, 6, 8 …

8. Vens Orbits Sun-synchronic LST : 10h30 Altitude: 720 km Inclination: 98.27° 2 days cycle: day 1 & day 2 orbits

9. Vens Acquisitions: tilting capability ± 30° along/across track

10. Vens Orbits and observing capabilities ± 30° Tilt DAY 2 DAY 1 DAY 2 DAY 1

11. Vens Orbits and observing capabilities ± 30° Tilt DAY 2 DAY 1 DAY 2 DAY 1

12. Vens Orbits and observing capabilities Sun-synchronic LST : 10h30 Altitude: 720 km Inclination: 98.27°

13. VENmS Imaging capabilities • Swath:27.56 km • Nominal requirements • 50 sites of 27x 54 km + calibration and image quality sites • 140 images of 27x27 km within 2 days (>20000/year) • 30 images on the most demanding orbit • Data strips longer than 54 km are feasible • Angular sampling could be achieved for a few sites (± 30° roll and pitch) • Moon viewing for calibration

14. Camera : Band Setting Simulated vegetation reflectances for 3 different Chlorophyl content

15. Band Setting (Requirements)

16. Image quality • Needs • Spatial and temporal image composites that can be used over a whole area to monitor seasonal and interannual evolutions • Need to provide consistent and homogeneous measurements through time and space, with physical meaning (reflectances) • Requirements • Geometrical registration (within bands  0.25pix, multitemporal 3m) • Radiometric calibration (3-5%), knowledge of the spectral responses, and spectral stability • Minimisation of perturbing effects : directional and atmospheric. Maximum shift of the time of overpass throughout the mission duration: lower than ± 5 minutes – Constant view zenith angle ± 2 degrees

17. Ground segment : Products Level 1: single acquisition Geometrically corrected (maps) of top of the atmosphere reflectances. One map projection per site. Level 2: single acquisition, geophysical variables Surface reflectances, atmospheric water vapor content and aerosol optical depth Level 3 : time composite, geophysical variables Surface reflectances, atmospheric water vapor content and aerosol optical depth All the acquired images will be freely available by ftp less than 1 month after acquisitions

18. Sites’ selection • Deadline for outline proposals of Venms sites and data use was 28th june 2006 • Proposals for additional sites are still considered, as second priority, if they are located in regions with little demands • Simulation of sites acquisitions is being carried out : technical feasibility, trade-off scenarios • Selection of the sites is still pending on technical issues • The plan is to acquire images over the selected sites during the whole 2.5 years of the mission

19. Objective of the workshop • Present the current status of the mission • Present levels 2 and 3 algorithms and existing/forthcoming data-sets • Illustrate the benefit of the mission by some examples • Answer your questions • Networking of scientists interested by the Venµs mission and more generally by high resolution/high repetitivity data • Listen to your needs and requests • Discussion on possible additional products or innovative uses • Coordination of efforts in the frame of calls for proposals (Tosca, PNTS, Interreg, FP7, …) and Sentinel-2 preparation