Copernicus Sentinel-2 Global Mosaic · 2018-10-18 · Copernicus Sentinel-2 Global Mosaic Objective and scope •Generating composites of Sentinel-2 L2A surface reflectance data consisting

www.s2gm.eu Copernicus Sentinel-2 Global Mosaic

Copernicus Sentinel-2 Global Mosaic

A short introduction

9th October 2018Carsten Brockmann, Brockmann Consult, Service Coordinator S2GM

http://www.s2gm.eu/


http://www.s2gm.eu/


Objective and scope• Generating composites of Sentinel-2 L2A

surface reflectance data consisting of original observations, the best representative pixel approach

• Global coverage

• Different compositing periods from 1-day to annual, three different spatial resolutions

• Analysis-ready data for direct and convenient usage

• Use cases include but are not limited to REDD+ activities, i.e. monitoring land use and deforestation

• State-of-the-art service provision

• Expert support

• Opening to public in October 2018

http://www.s2gm.eu/


Service Offer

10m 20m 60

Yearly

Quarterly

Monthly

10-days

Daily

Surface reflectances (from sen2cor L2A)Best representative spectrum

Quality information at pixel and product level

Products

Service• User defined area selection• Configurable output (bands, format)• Processing on-demand• Downloader tool

http://www.s2gm.eu/


Processing Chain – Main Concepts

Input tile QC

Mosaicking pixel-level

I/O QC

Output tile QC pass

reject

pass

reject

tile-level QC rules

tile-level QC rules

pixel-level QC rules

L2A tile stack

recordrecord

QC meta-data

L3 mosaic

tile product

L2A filtered

tile stack

L3 mosaictile with per-pixel

QC

http://www.s2gm.eu/


Two Mosaicking Algorithms • Short-term composite < 4 valid observations:

Decision tree approach evaluating scene classification, similar to Landsat WELD

• MEDOID >= 4 observations: Multidimensional median on the entire spectrum, statistical approach

• Rigid pre-processing to eliminate invalid observations

• Generating mosaics pixel by pixel from original observations

http://www.s2gm.eu/


Test Sites

http://www.s2gm.eu/


Valenciennes T31UER – spectral analysissufficient number of valid spectra for MEDOID

http://www.s2gm.eu/


Composite Algorithm - Wilhelmshaven V1-Delivery

28/09/2018

Wilhelmshaven Yearly composite: April 2017 – March 2018

60m spatial resolutionRGB + Mask – STC-Algorithm + Medoid-Algorithm

Monthly composites

04/2017 05/2017

03/2018

http://www.s2gm.eu/



10

0

0.1

0.2

0.3

0.4

0.5

0.6

400 600 800 1000 1200 1400 1600 1800 2000 2200

surf

ace

refl

ecta

nce

Spectra - Urban - 5x5

15.04.2017 15.05.2017 15.06.2017 15.07.2017 15.08.2017 15.09.2017 15.10.2017

15.11.2017 15.12.2017 15.01.2018 15.02.2018 15.03.2018 01.10.2017


60m spatial resolution

http://www.s2gm.eu/


0

0.1

0.2

0.3

0.4

0.5

0.6

400 600 800 1000 1200 1400 1600 1800 2000 2200

surf

ace

refl

ecta

nce

Spectra - Lake - 5x5

15.04.2017 15.05.2017 15.06.2017 15.07.2017 15.08.2017 15.09.2017 15.10.2017

15.11.2017 15.12.2017 15.01.2018 15.02.2018 15.03.2018 01.10.2017


28/09/2018 Copernicus Sentinel-2 Global Mosaic

11



http://www.s2gm.eu/


0

0.1

0.2

0.3

0.4

0.5

0.6

400 600 800 1000 1200 1400 1600 1800 2000 2200

surf

ace

refl

ecta

nce

Spectra - Forest - 5x5

15.04.2017 15.05.2017 15.06.2017 15.07.2017 15.08.2017 15.09.2017 15.10.2017

15.11.2017 15.12.2017 15.01.2018 15.02.2018 15.03.2018 01.10.2017



12



http://www.s2gm.eu/


0

0.1

0.2

0.3

0.4

0.5

0.6

400 600 800 1000 1200 1400 1600 1800 2000 2200

surf

ace

refl

ecta

nce

Spectra - Agriculture - 5x5

15.04.2017 15.05.2017 15.06.2017 15.07.2017 15.08.2017 15.09.2017 15.10.2017

15.11.2017 15.12.2017 15.01.2018 15.02.2018 15.03.2018 01.10.2017



13



http://www.s2gm.eu/


0

0.1

0.2

0.3

0.4

0.5

0.6

400 600 800 1000 1200 1400 1600 1800 2000 2200

surf

ace

refl

ecta

nce

Spectra - Bare area - 5x5

15.04.2017 15.05.2017 15.06.2017 15.07.2017 15.08.2017 15.09.2017 15.10.2017

15.11.2017 15.12.2017 15.01.2018 15.02.2018 15.03.2018 01.10.2017



14



http://www.s2gm.eu/


MOSAIC HUB

http://www.s2gm.eu/


Mosaic generation and distribution

• On-request generation of tailored mosaics

• Interactive user interface for productordering

• Mosaic image products

• Time-series feature for single pixel and 3x3 pixels

• Desktop applicationwith convenient download manager

http://www.s2gm.eu/


Tailoring mosaics

• Mosaics products can be tailored with respect to• Compositing period (day, 10-day,

month, quarter, year)

• Area of interest

• File format (GeoTIFF, JP2, NetCDF)

• Spatial resolution (10, 20, 60m)

• Coordinate system (WGS84, UTM)

• Bands to be included

• Auxiliary information (AOT, geometry, scene classification, etc.)

http://www.s2gm.eu/


Documentation and support• Algorithm Theoretical Basis Document

(ATBD)

• Online User Manual

• Expert support via CLMS service desk

http://www.s2gm.eu/


Consortium

• Three European SMEs with complementary expertise in Earth Observation since many years.

• Clearly defined roles in S2GM service

• Managing contract and consortium

• Mosaicking algorithms• Sentinel-2 (pre-)

processing expertise

• Maintaining S2 L2A archive

• Mosaic Hub technology• Distribution of products

• Internal quality control• Thematic expertise land

http://www.s2gm.eu/


SummaryCopernicus Sentinel-2 Global Mosaic service

• provides scientifically sound mosaics of Sentinel- 2 surface reflectance data on a global scale

• is fit for various applications

• is free to use by everyone

• accessible via Copernicus Land Monitoring Service (CLMS)

• will be publicly advertised in October

• is operated by a team of dedicated experts ready to support users

http://www.s2gm.eu/


Thank you

Contact [email protected] the Service desk of CLMS at

https://land.copernicus.eu/contact-form for more information!

http://www.s2gm.eu/

mailto:[email protected]

https://land.copernicus.eu/contact-form

Documents

Copernicus Sentinel-2 Global Mosaic · 2018-10-18 · Copernicus Sentinel-2 Global Mosaic Objective and scope •Generating composites of Sentinel-2 L2A surface reflectance data consisting