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Sentinel-4 and -5 Status and Level-2 Products. Ben Veihelmann , Jörg Langen , Dirk Schüttemeyer , Paul Ingmann ESA/ESTEC. OMI Science Team Meeting 18 March 2014, KNMI, De Bilt , T he Netherlands. O verview. Sentinel-4: mission implementation and Level-2 products
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Sentinel-4 and -5Status and Level-2 Products Ben Veihelmann, JörgLangen, Dirk Schüttemeyer, Paul Ingmann ESA/ESTEC OMI Science Team Meeting 18 March 2014, KNMI, De Bilt, The Netherlands
Overview • Sentinel-4: mission implementation and Level-2 products • Sentinel-5: mission implementation and Level-2 products • AROMAT campaign: preparation of future validation
The Sentinel Missionsfor Copernicus Atmosphere Services GEOstationary (GEO) • Hourly revisit time over Europe • Mainly air quality • Diurnal cycle of tropospheric composition • Sentinel-4 Low Earth Orbit (LEO) • Daily revisit time global coverage • Climate, air quality, ozone & UV • Tropospheric & stratospheric composition • Sentinel-5 • Sentinel-5 Precursor
Sentinel-4/-5/-5P Mission Implementation (1) on MTG sounder (GEO) (2) on MTG imager (GEO) (3) on MetOp-SG (LEO) (4) on dedicated platform (LEO) (5) on SNPP/JPSS (LEO) (*) synergy on higher data level UVN = Ultraviolet + Visible + Near infrared FCI = Flexible Combined Imager IRS = InfraRedSounder LI = Lightning Imager UVNS = UVN + Short wave infrared VII = Visible/Infrared Imager (MetImage) IAS = Infrared Atmospheric Sounder (IASI-NG) 3MI = Multi-viewing, -channel, -polarisation Imager TROPOMI = TROPOspheric Monitoring Instrument VIIRS = Visible Infrared Imaging Radiometer Suite CrIS = Cross-track Infrared Sounder OMPS = Ozone Mapping Profiler Suite MTG = Meteosat Third Generation MetOp-SG = MetOp-Second Generation SNPP = Suomi National Polar-orbiting Partnership JPSS = Joint Polar Satellite System
Sentinel-4/UVN Instrument Courtesy Astrium
Sentinel-4/UVN Instrument Characteristics Radiometric accuracy1.8% (315-500 nm), 2.3% elsewhere Polarisation sensitivity<0.7% Spectral features<0.05% Signal-to-Noise Ratiocompliant Spatial Sampling8 km at 45˚N Geographic Coverage Area (GCA) Europe + Sahara Repeat Cycle1 h over Reference Area (RA) 300 400 500 600 700 800 UV-vis NIR Wavelength (nm)
Sentinel-4 Level-2 Products Who takes care of IRS alone products such as CO, HNO3?
Sentinel-4 Level-2 Performance Estimate(IUP, RAL, Noveltis) Assumptions • polluted scenario at 50˚N, 15h local time • radiometric offset error small, spectral calibration successful • cloud fraction up to 20%
Sentinel-4 Level-2 Performance Estimate(IUP, RAL, Noveltis) • Valuable aerosol data from O2A band • in morning/afternoon expected Assumptions: European background aerosol profile User requirement Aerosol Optical Depth Noise Error Total Column R. Siddans, STFC Rutherford Appleton Laboratory 06h 09h 12h 15h 18h Boundary Layer
Sentinel-4 Level-2 Processor Development Challenges Tropospheric NO2 diurnal variation • good precision and accuracy • avoid diurnal biases! • need to account for • surface anisotropy • tropospheric profile • stratospheric sub-column • aerosol vertical distribution • aerosol phase function Aerosol layer height • from O2A band • little heritage • spectroscopy • pseudo-noise mitigation • spectral calibration • computational speed Aerosol & surface characteristics • joint retrieval from aggregated data • little heritage • processor architecture • computational speed
Sentinel-4 Level-2 Pre-development SURMACED (BIRA, GC, LOA, IM)GPGPU (LOA, Catalyst) Objective • Aerosol & surface reflectance from temporally aggregated radiance • Application to real satellite measurements • Validation based on real measurement Approach • SURMACED (finalised): GRASP algorithm, performance demonstrated for favourable illumination conditions (summer), driver NO2 retrieval • GPGPU (ongoing): Proxy data from GOCI, reference from AERONET and PARASOL GOCI on COMS Bi-directional Reflectance Factor, 440 nm, various surface types
Sentinel-4 Level-2 Pre-development AEROPRO (KNMI) Objectives • Aerosol layer height retrieval from O2A-band • Application to real satellite measurements • Validation based on collocated measurements Status • GOSAT (0.016 nm) + airborne lidar finalised • GOME-2 (0.5 nm) + ground based lidar almost finalised • poster Bram Sanders GOME-2 on MetOp CarbonExp Campaign 2011 TANSO on GOSAT Lidar on FAAM CarbonExp Campaign 2011 Collocated GOSAT target mode airborne lidar CarbonExp Campaign 2011
Sentinel-4 Level-2 Processor Development ITT early 2014 Build on heritage Challenges Consortium formation now!
Mission Elements: Sentinel–5LEO Atmospheric Mission Applications: • air quality, climate forcing and stratospheric ozone, tropospheric chemistry Instrumentation: • UV-VIS-NIR-SWIR spectrometer • Use of thermal IR sounder, cloud • imager and polarisation imager • UV-Visible (270-500nm) • NIR (685-775nm) • SWIR (1590–1675nm; 2305-2385nm) • Spectrometers with spectral resolutions between 0.25 nm and 1.0 nm • Spatial sampling with 50 (T)/15 (G) km < 300nm and 15 (T)/5(G) km > 300 nm • Global daily coverage • Sun-synchronous Low Earth Orbit platform at 824 km mean altitude • Embarked on EPS-SG, operated by EUMETSAT
Possible Level-2 Products from Sentinel-5 UVNS SO = stratospheric ozone AQ = air quality CL = climate (1) Only observed in strongly polluted areas (volcanic eruptions, major power plants) (2) Priority 1 not as geophysical product itself, but for use in correcting retrievals of other products (3) Priority 2 for instrument development; priority 1 for Level-2 product development
Possible Sentinel-5-relevant Level-2 Products from other instruments on Metop-SG IAS (IASI-NG) O3 and CO profiles SO2, NH3, CH3OH, HCOOH CH4, H2O, HNO3, PAN C2H2, HCN CFC-11, CFC-12, C2H4, N2O, HONO, CO2, volcanic ash 3MI aerosol/cirrus optical depth aerosol single scattering albedo, effective radius, refractive index surface reflectance VII (MetImage) aerosol/cirrus optical depth aerosol type, effective radius, single scattering albedo cloud characterisation
Sentinel–5 scientific study activities Consolidation of requirements • radiometric errors (offset, scaling, spectrally varying) • spatial co-registration (cloud, surface albedo impact), spatial resolution • spectral resolution vs. SNR • knowledge of slit function • added value of O2-B band Performance assessment • error budget • band trade-offs (eg. 2-band vs. 3-band CH4 retrieval) • vertically resolved aerosol product • spectroscopic errors • fluorescence
AROMAT (Airborne ROmanian Measurements of Aerosols and Trace gases) • Objectives • To combine airborne, satellite and coincident ground activities • To investigate consistency and complementarity of different measurement approaches • Targets • NO2, SO2, and aerosols in exhaust plumes of large power stations (Turceniand Rovinari)and around the Bucharest urban area. • Setup • 2 imaging DOAS, scanninglidar, NO2sondes • high pollution levels and strong gradients
Sentinel-4 and -5Status and L2 Products Ben Veihelmann, JörgLangen, Dirk Schüttemeyer, Paul Ingmann ESA/ESTEC Thanks for listening! OMI Science Team Meeting 18 March 2014, KNMI, De Bilt, The Netherlands
Preliminary spectral fit-windows per Level-2 product UV-Visible band Near Infrared band
Sentinel-4 Instrument on Meteosat Third Generation (MTG) MTG-Sounder InfraRed Sounder (IRS) Sentinel-4/UVN (S4/UVN) MTG-Imager Flexible Combined Imager (FCI) Lighting Imager (LI) UVN = UV + Visible + Near infrared