Alvarado, Leonardo

Bracher, Astrid

Dinh, Dieu

Silva, Brenner

Soppa, Mariana A.

English

Electronic Publication Information Center

Intercomparison of DESIS, Sentinel-2 (MSI) and Sentinel-3 (OLCI) data for water colourapplicationsM. A. Soppa*, D. A. Dinh, B. Silva, F. Steinmetz, L. Alvarado, A. Bracher*msoppa@awi.deWhat can we see with S2, S3 and DESIS?v Lake Constance true colour composites of Level 1 (R:665, G:560, B:490) in 14.08.2021 Sentinel-2B – 10 m Sentinel-3B – 300 mWhat can we see with S2, S3 and DESIS?DESIS – 30 mv Lake Constance true colour composites of Level 1 (R:665, G:560, B:490) in 14.08.2021 Sentinel-3B – 300 mAtmospheric correction over waterv The information of the radiance (L) in the VIS-SWIR part of the spectrum can be used to infer the water optical properties.v The total radiance (LTOA) measured by the sensor has different origins:• atmosphere (La)• surface (Lr)• water (Lw)v Lw is only a small part of LTOA (max. 10%)!!The Polymer Algorithmv Polymer: POLYnomial based algorithm applied to MERIS (Steinmetz et al. 2011)v Python package available at https://www.hygeos.com/polymerv Polymer is (almost) directly applicable to hyperspectral sensors.v Spectral matching algorithm; uses full available spectrum.v Improved spatial coverage compared to other algorithms due to its possibility to recover the Ocean Colour in presence of sun glint. v 3 step process: (1) Pre-correction of the top of atmosphere radiance, (2) spectral matching of the atmospheric and water models, and retrieval of the (3) normalized water-leaving reflectance.v Polymer applied to hyperspectral sensors is as good as for multispectral sensors (Soppa et al. 2021).HICO (10-03-2014) - Rrs 553 nmPolymer L2genHow Polymer performs applied to DESIS?DESIS L1BSentinel-2-MSIL1CSentinel-3-OLCIL1Polymer ACChl-a conc. and  normalized water leaving reflectancev DESIS, S2-MSI, S3-OLCI images at 8 study sites were processed with Polymer AC and intercompared.Ariake: Chl-a concentration (mg/m3)DESIS - 04.02.2019Nori aquaculture sites and tidal flatsAriake: Chl-a concentration (mg/m3)S2-MSI - 01.02.2019DESIS - 04.02.2019- Grey pixels are flagged regions due to several factors: cloud, thick aerosol plume, optimized parameters out of bunds, etc.- More pixels are flagged correctly by Polymer in DESIS than S2-MSI.Ariake: Chl-a concentration (mg/m3)DESIS - 04.02.2019 S3-OLCI- 04.02.2019AriakeDESIS L1B – Band 1 – V0210 DESIS L1C – Band 1 – V0213v Bands 1 to 6 of L1B DESIS affected by this region with radiance = 0, but the region affected decreases with increasing wavelength à sensor degradation.v L1C V0213 is less affected.v Differences due to data version or data level?Galata: Chl-a concentration (mg/m3)• Adjacency effect along the coastline.• Striping effect à use L1C data.DESIS - 13.02.2020Chl-a concentration (mg/m3)Coccolithophore bloomGalata: Chl-a concentration (mg/m3)• Adjacency effect along the coastline.• Striping effect à use L1C data.DESIS - 13.02.2020Lucinda: Total Suspended Matter (mg/L)DESIS - 06.12.2019 S2-MSI- 05.12.2019• TSM derived using a simple empirical algorithm (Nechad et al., 2010).• Similar distribution and magnitude.Lucinda: Chl-a concentration (mg/m3)• Better differentiation of TSM and Chl-a with DESIS than S2-MSI. DESISS2-MSILucinda: Chl-a concentration (mg/m3)• Larger differences at the blue bands (443 and 490 nm).• Better agreement at the “ocean” than in the at the “channel”.S2-MSIAERONETSummaryv Consistent retrievals of DESIS products using Polymer atmospheric correction algorithm.v Overall good agreement between Polymer-DESIS and Polymer-S2-MSI products.v DESIS-Polymer retrievals will be improved by:® replacing DESIS L1B data by L1C;® avoiding the < 430 nm due to manufacturing defects;® testing different band settings.v Hyperspectral radiometric data in coastal and inland waters from research cruises, field campaigns, validation sites as WATERHYPERNET (Vansteenwegen et al., 2019), WISPstationnetwork (Bresciani et al., 2020). Acknowledgmentsv This investigation was supported by the Federal Ministry of Economics and Technology (BMWi) and DLR grants 50EE1923 within the EnMAP scientific preparation program, and 50EE1915 within the project TypSynSat (Monitoring the Phytoplankton Functional Types by Synergistic Exploitation of Multi- and Hyperspectral Satellite Observations).v DLR and Teledyne are acknowledged for DESIS level 1 satellite data.v ESA is acknowledged for Sentinel-2 and Sentinel-3 level 1 data.

Intercomparison of DESIS, Sentinel-2 (MSI) and Sentinel-3 (OLCI) data for water colour applications

https://epic.awi.de/id/eprint/54762/1/DESIS_Workshop2021_Soppa.pdf

Intercomparison of DESIS, Sentinel-2 (MSI) and Sentinel-3 (OLCI) data for water colour applications

Abstract

Similar works

Full text

Available Versions

Electronic Publication Information Center