Ben Gurion University. The VENμS mission: Earth Observation with High Spatial and Temporal Resolution Capabilities. G. Dedieu 1 , O. Hagolle 2 , A. Karnieli 3 , S. Cherchali 2 P. Ferrier 2 and Y. Yaniv 4. 1 CESBIO, Toulouse Cedex 9, France 2 CNES Toulouse France - PowerPoint PPT Presentation
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Ben Gurion Univers ity Mission scientists (PI's) : Gérard Dedieu & Arnon Kanieli G. Dedieu 1 , O. Hagolle 2 , A. Karnieli 3 , S. Cherchali 2 P. Ferrier 2 and Y. Yaniv 4 The VENμS mission: Earth Observation with High Spatial and Temporal Resolution Capabilities 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
G. Dedieu1, O. Hagolle2, A. Karnieli3, S. Cherchali2 P. Ferrier2 and Y. Yaniv4
The VENμS mission: Earth Observation with High Spatial and Temporal Resolution
Capabilities
1 CESBIO, Toulouse Cedex 9, France2 CNES Toulouse France
3 The Remote Sensing Laboratory, Ben Gurion Univ. of the Negev, Israel4 MBT Space Division, Israel Aircraft Industries ISRAEL
VENS
VENS 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 high repetitivity, high resolution remotely sensed measurements acquired by a super spectral imaging radiometer
To develop and experiment a dedicated ground segment able to deliver state of the art quality products
Why high temporal repetitivity ?
June 5th 2006 June 14th 2006 June 23th 2006 June 29th 2006
(rapeseed harvest, sunflower growth)
Formosat-2 images
Indice foliaire 2006
VENS 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 capability30 deg across and along track
View angleConstant view angle can be achieved every 2 days, at constant local solar time
Stereo pairs with a small angle difference at 620nmCloud screening based on altitude, DEM generation
Nominal requirements50 sites of 27x 54 km + calibration and image quality sites140 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
Camera : Band Setting
Simulated vegetation reflectances for 3 different Chlorophyl content
Band Setting (Requirements)
Bands 0 (μm)Δ
(nm)
SNR for Lmin
at 5.3GSD
Required Resolution
(meters)
SNR for Lmin
at resolution
Main Driver
B1 0.420 40 25 21.2 100 Aerosols
B2 0.443 40 25 21.2 100Aerosols,
clouds
B3 0.490 40 25 21.2 100 Aerosols
B4 0.555 40 50 10.6 100 Land
B5 0.620 40 50 10.6 100 Land
B6 0.620 40 50 10.6 100DEM, image
quality
B7 0.667 30 45 10.6 90 Land
B8 0.702 24 55 10.6 110 Land
B9 0.742 16 55 10.6 110 Land
B10 0.782 16 55 10.6 110 Land
B11 0.865 40 50 10.6 100 Land
B12 0.910 20 25 21.2 100 Water vapor
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)
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
Ground segment : Products
Level 1: single acquisitionGeometrically corrected (maps) of top of the atmosphere reflectances. One map projection per site.
Level 2: single acquisition, geophysical variablesSurface reflectances, atmospheric water vapor content and aerosol optical depth
Level 3 : time composite, geophysical variablesSurface 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
Sites’ selection
Deadline for outline proposals of Vens 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 issuesThe plan is to acquire images over the selected sites during the
whole 2.5 years of the mission
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 dataListen to your needs and requestsDiscussion 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
