WP300 – Recommendations for S2 and S3 Calibration Test Sites Selection and Characterisation WP300 – Recommendations for S2 and S3 R. Santer and B. Berthelot Final meeting, ESRIN, Frascati, April 21, 2009

Outlines General requirements Presentation of S2 Vicarious calibration of S2 Presentation of S3 Vicarious calibration of S3 Synergy between S2 and S3 Proof of concept with the parents

Starting from level 1or 1+ TOA reflectance instead of TOA radiance A perfect instrument Stray light correction Equalization of the detectors Smile correction for OLCI Need to redefine L1 or to have breakpoints in L2

S2, spectral

S2, spectral

S2, spatial

LES, S2 radiometric The reference method Need to cover the MIR How will pay how for campaigns?

CEOS and LES, Sharing the data

ESA and LES, Sharing a network of radiometers

CNES (i) and LES, Sharing a processing chain

NASA and LES, The LES AERONET The ocean colour goes to AERONET Why not a calval AERONET AERONET to collect data and distribute different levels

WES and S2 Good to have dark target calibration S2 a water colour mission? AERONET ocean colour

LNES: S2 inter temporal Better revisit time than ETM+ BRDF of the site Good to control clear sky condition 1.37 µm for cirrus clouds Good to control aerosol In situ Space

The absorption spectral bands Needs for calibration Absolute for 1.37 *µm Interband for the water vapour Methodology Aircraft at high altitude for absolute (AVIRIS) Very bright targets (sunglint) for inter band

S3, spectral

S3, spatial OLCI SLSTR

S3 and LES Geo-localisation Size of the pixel Statistical approach Spatial heterogeneity describes by S2 Statistical approach Automat to characterize surface and atmosphere Sensor inter calibration

S3 and WES AERONET ocean colour Equipped commercial ships Case 2 water TRIOS SIMBAD

S3 and WNES Inter band in the NIR So called Rayleigh in the visible Better if information on the aerosols Sunglint for inter band Synergy with SLSTR

AERONET case 1water

Summary radiometry

Spectral calibration Frauhoffer for OLCI Reference to high resolution spectrometers Inter sensor with OLCI specific spectral setting: SLSTR S2

Proof of concept: S2 with ? LES: La Crau with ROSAS WES: Ocean Colour Inter temporal: Desertic sites Characterize the BRDF: POLDER

Proof of concept: S3 with MERIS LES: MERIS FR, La Crau with ROSAS WES: AERONET Ocean Colour LNES: Inter temporal WNES CNES or NASA sites for NIR and Rayleigh AERONET case 1 for Rayleigh and sunglint