1. SADE Export Web Site
Claire Tinel, Denis Blumstein, Patrice Henry - CNES Pascale Lafitte - CNES
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

2. Outline CNES Calibration Methods SADE Database SADE Export Web Site
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

3. In-flight calibration of optical sensors using natural targets
Main calibration Methods
5 calibration methods are routinely used to calibrate sensors
These calibration methods are used operationally at CNES
for POLDER 1, 2, 3 (PARASOL), VEGETATION 1 and 2,
for SPOT satellites, MERIS, MODIS, FORMOSAT-2 and KOMPSAT-2
+ Calibration over equipped test sites
Coming soon : lunar calibration
(Venµs and PLEIADES)
Deserts
Sun Glint
Rayleigh
Snow
Clouds
(Tuz Golu Campaign)
(La Crau)
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

4. Multi-temporal Calibration methods
Deserts : cross and multi-temporal calibration
Comparison of measured reflectance with reference reflectance (same or other sensor) acquired in the same geometrical conditions
Sun glint calibration : interband calibration
Observe the white reflection of the sun over the ocean surface
Interband calibration w.r.t. a reference spectral band (620 nm)
Rayleigh calibration : absolute calibration of bands < 700 nm
Observe the atmosphere over ocean (dark)
Rayleigh scattering : > 80% of signal
Deep convective clouds : interband calibration
Observe the white reflection of the sun over clouds
Interband calibration w.r.t. a reference spectral band
Snow : multitemporal calibration and/or intersensor calibration
Observation of stable snowy sites at high altitude (3200 m)
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

5. SADE: Structure d’Accueil de Données d’Etalonnage (Calibration Data Repository)
Multi-temporal calibration and cross-calibration and/or absolute calibration of optical sensors (visible → NIR) through different methods
Easy data management, link between satellite measurements and calibration results (traceability)
Common calibration tool for all sensors for one given method
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

6. SADE Base Content: MUSCLE Tools (Front-End Graphic)
TOA reflectances
Calibration results (coefficients)
Synthesis results (means, models)
MUSCLE Tools (Front-End Graphic)
Extraction and insertion of measurements
Calibration
Synthesis
Exogen data (climatologic models 4/day )
NCEP : pressure, water vapour
EPTOMS : ozone
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

7. SADE
Exogen data
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

8. SADE For each measurement: For each "elementary " calibration result:
Mean TOA reflectance value + standard deviation per band
Geometrical conditions : zenithal and azimuthal viewing/solar angles
Pressure, water vapour, ozone, aerosols optical depth
Product name N1, Acquisition date
SADE identifier
For each "elementary " calibration result:
One calibration coefficient per band
Name of the method
Tool name, tool version and tool parameters
Processing date
User name
SADE identifier
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

9. SADE Export Web Site : deserts data
Systematic collect of satellite acquisitions on desertic sites :
data ~ 10 % of SADE content
Operational monitoring of CNES sensors calibration (on a monthly basis) :
SPOT(s)/High Resolution
SPOT(s)/Vegetation-1&2
PARASOL
Calibration monitoring and intercalibration of other sensors on a regular basis (through cooperation agreements with other space agencies)
High resolution : Formosat-2 (Taiwan NSPO), Kompsat-2 (South Korea KARI)
Coarse resolution : MERIS (ESA), MODIS/AQUA
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

10. 20 sites selected over North Africa and Arabia
SADE Export Web Site : deserts data
20 sites selected over North Africa and Arabia
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

11. SADE Export Web Site : deserts data
Desert Sites Database (from 1985 until 2010)
AVHRR
POLDER
SPOT
MERIS
MODIS
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES

12. SADE Export Web Site : deserts data
SADE Export web site (currently under development):
Provides TOA calibrated reflectances on desertic sites for the GSICS community
Access with a login user
Updating every 6 months
Still remains to do:
Synthesis table
Sensors description
GSICS community opening : March 2010
Desert SADE Data Access
GSICS WG Meeting – Feb 2010 – Claire Tinel / CNES