1. Progress report on work at the CHRIS-PROBA study site on Thorney Island, UK Ted Milton, University of Southampton, UK Karen Anderson, University of Exeter, UK

2. Location of Thorney Island CHRIS / PROBA : 16 Sept 2003

3. CHRIS PROBA data from Thorney Island DateComments 14 th Sept 2003CASI and ATM data collected two days later. 17 th April 2004Some cloud cover. 7 th October 2004Excellent quality. 14 th September 2003

4. CHRIS PROBA data from Thorney Island DateComments 14 th Sept 2003CASI and ATM data collected two days later. 17 th April 2004Some cloud cover. 7 th October 2004Excellent quality. 14 th September 2003

5. Ground spectra collected with a dual field-of-view GER1500 spectroradiometer and single beam ASD FieldSpec Pro Measuring aerosol optical thickness using a Microtops sunphotometer.

6. Intertidal vegetation mapping 14 th September 2003 Land cover survey during summer 2004. String of 3 images co- registered using GCPs. Per-pixel classification of images from each view angle.

7. Intertidal vegetation mapping 14 th September 2003 Land cover survey during summer 2004. String of 3 images co- registered using GCPs. Per-pixel classification of images from each view angle. Atmospheric correction. Per-pixel classification of the multi-angle data set. Soft classification / parcel based methods.

8. QUASAR methodology (Teillet et al., 2001) Atmospheric model Radiance at TOA Average reflectance of ground calibration target

9. Atmospheric correction : FLAASH CASI : 16 th April 2003 ground casi concrete ground casi asphalt

10. Reflectance of concrete calibration target High precision dual-beam mobile spectroradiometer High precision dual-beam mobile spectroradiometer Two matched GER1500 spectroradiometers Two matched GER1500 spectroradiometers

11. Long-term change in reflectance of bright target

12. Afternoon spectra significantly lower reflectance, esp. in the visible region

13. Each sequence shows a small variation with solar zenith angle. Not large enough to account for the difference between am and pm. Neither is the spatial uncertainty of location...

14. First clue to what is affecting the concrete reflectance is found in the met. data...

15. Onset of sea breeze in late morning is confirmed by wind direction measurements from a buoy in Chichester harbour.

16. But how can a change in wind direction cause a statistically significant change in reflectance ? Cutting a long story short...

17. Estimating reflectance of bright target Towards a model relating concrete reflectance to meteorological data. Towards a model relating concrete reflectance to meteorological data. Meteorological data Precipitation Wind Air temp. Rel humidity D:G ratio Surface Moisture Biotic factors Surface temperature Surface properties Surface composition Nadir Reflectance Dew Point Time since rainfall

18. 30th April 2004 9th Sept 2004 16th Sept 2004 22nd Nov 2004 17th Dec 2004 Vicarious Calibration site Railroad Valley, Nevada © Sira Technology, 2004

20. CHRIS on PROBA : 7 th Oct 2004

22. An exemplar data set for testing atmospheric correction methods CHRIS data from 14 th September 2003. CHRIS data from 14 th September 2003. CASI and ATM from 16 th September 2003. CASI and ATM from 16 th September 2003. Spectral ground data from 16 th September 2003 Spectral ground data from 16 th September 2003 Spectra from ground calibration targets: Asphalt : spectral radiance, 300-1,000 nm, every 30 s during the flights. Spectral reflectance 300-1,000 nm immediately after the flights. Concrete and Grass : Spectral reflectance 300-1,000 nm (immediately after the flights). Atmospheric data: Water vapour (equivalent thickness) Aerosol optical thickness (AOT) : 5 spectral bands. Direct beam irradiance : 5 spectral bands. Global and diffuse quantum flux (PAR) : every 5 s Global broadband irradiance : every 5 s Global spectral irradiance : 300-2,400 nm, every 30 s Relative humidity, air temperature and barometric pressure, every 30 s.

23. CHRIS PROBA data from Thorney Island 17 th April 2004 CH_040417_3FE3_31.hdfCH_040417_3FE4_31.hdf CH_040417_3FE5_31.hdf CH_040417_3FE6_31.hdf

24. CHRIS PROBA data from Thorney Island CH_041017_479F_31.hdf CH_041007_47A0_31.hdf CH_041017_47A1_31.hdfCH_041017_47A2_31.hdfCH_041017_47A3_31.hdf

25. Thorney Island calibration site Data provided by NERC ARSF, 18/6/02