The normalised Sentinel-1 Global Backscatter Model, mapping Earth’s land surface with C-band microwaves

Scientific Data, vol. 8, pp. 277

Abstract

We present a new perspective on Earth's land surface, providing a normalised microwave backscatter map from spaceborne Synthetic Aperture Radar (SAR) observations. The Sentinel-1 Global Backscatter Model (S1GBM) describes Earth for the period 2016-17 by the mean C-band radar cross section in VV- and VH-polarisation at a 10 m sampling. We processed 0.5 million Sentinel-1 scenes totalling 1.1 PB and performed semi-automatic quality curation and backscatter harmonisation related to orbit geometry effects. The overall mosaic quality excels (the few) existing datasets, with minimised imprinting from orbit discontinuities and successful angle normalisation in large parts of the world. Regions covered by only one or two Sentinel-1 orbits remain challenging, owing to insufficient angular variation and not yet perfect sub-swath thermal noise correction. Supporting the design and verification of upcoming radar sensors, the obtained S1GBM data potentially also serve land cover classification and determination of vegetation and soil states. Here, we demonstrate, as an example of its potential use, the mapping of permanent water bodies and evaluate against the Global Surface Water benchmark.

Authors 12

1. Bernhard Bauer-Marschallinger corresponding

   TU Wien

   Affiliation as printed

   Technische Universität Wien, Department of Geodesy and Geoinformation, 1040, Vienna, Austria. bbm@geo.tuwien.ac.at

   Technische Universität Wien, Department of Geodesy and Geoinformation, 1040, Vienna, Austria

2. Senmao Cao

   TU Wien

   Affiliation as printed

   Earth Observation Data Centre for Water Resources Monitoring (EODC), 1030, Vienna, Austria

   Technische Universität Wien, Department of Geodesy and Geoinformation, 1040, Vienna, Austria

3. Claudio Navacchi

   TU Wien

   Affiliation as printed

   Technische Universität Wien, Department of Geodesy and Geoinformation, 1040, Vienna, Austria

4. Vahid Freeman

   TU Wien · University of Luxembourg

   Affiliation as printed

   Spire Global, Space Program, 2763, Sainte-Zithe, Luxembourg

   Technische Universität Wien, Department of Geodesy and Geoinformation, 1040, Vienna, Austria

5. Felix Reuß

   TU Wien

   Affiliation as printed

   Technische Universität Wien, Department of Geodesy and Geoinformation, 1040, Vienna, Austria

6. Dirk Geudtner

   European Space Agency · European Space Research and Technology Centre

   Affiliation as printed

   European Space Agency, European Space Research and Technology Centre, 2201 AZ, Noordwijk, The Netherlands

7. Björn Rommen

   European Space Agency · European Space Research and Technology Centre

   Affiliation as printed

   European Space Agency, European Space Research and Technology Centre, 2201 AZ, Noordwijk, The Netherlands

8. Francisco Ceba Vega

   European Space Agency · European Space Research and Technology Centre

   Affiliation as printed

   European Space Agency, European Space Research and Technology Centre, 2201 AZ, Noordwijk, The Netherlands

9. P. Snoeij Aachen Airbus Defense and Space

   Airbus (Netherlands)

   Affiliation as printed

   Airbus Defense and Space, 2333 CS, Leiden, The Netherlands

10. Evert Attema

    European Space Agency · European Space Research and Technology Centre

    Affiliation as printed

    European Space Agency, 2200 AG, Noordwijk, The Netherlands

11. Christoph Reimer
    Affiliation as printed

    Earth Observation Data Centre for Water Resources Monitoring (EODC), 1030, Vienna, Austria

12. Wolfgang Wagner

    TU Wien

    Affiliation as printed

    Earth Observation Data Centre for Water Resources Monitoring (EODC), 1030, Vienna, Austria

    Technische Universität Wien, Department of Geodesy and Geoinformation, 1040, Vienna, Austria