Data access

theia.cnes.fr

Presentation

The Venµs science mission is a joint research mission undertaken by CNES and ISA, the Israel Space Agency. It aims to demonstrate the effectiveness of high-resolution multi-temporal observation optimised through Copernicus, the global environmental and security monitoring programme. 

Venµs was launched from the Centre Spatial Guyanais by a VEGA rocket, during the night from 2017, August 1st to 2nd.

Thanks to its multispectral camera (12 spectral bands in the visible and near-infrared ranges, with spectral characteristics provided here), it acquires every 2 days 123 areas at a spatial resolution of 5 m. The end of this mission is foreseen in 2020, August.

The selected areas  cover the main terrestrial and coastal ecosystems in the world.

Geographical coverage

Some notions have to be explained in order to understand the number and the nature of the distributed data.

  • The area : Venµs acquires 123 different areas during its 2-day orbital cycle
  • The site : A site covers all or part of an area. In some cases (long areas, named as “composit”), a decomposition in elementary “sites”is made on the whole geographical footprint of the area. In the end, 159 different sites cover all the Venµs acquisitions.

The data distributed are the image products related to the sites. Among the 159 sites, 27 cover Israël. These latter are not distributed through Theia portal. In the end, 132 sites are downloadable through Theia distribution portal.

The geographical distribution of these 132 sites is given here.

Venus Sites map
A localisation of the Venus sites is available on OpenstreetMap
see in full screen

Contact

Olivier Hagolle
Cesbio
@O.Hagolle
Contributions

Satellite

Name : Venµs

Imaging mode : optical

Spectral bands : 12 bands from visible to near infrared

Resolutions : 5 m

Observation capability : 

  • Swath : 27 km
  • Revisit : 2 days

Coverage : 

  • Areas : 123 areas in the world, representing 159 elementary scientific sites
  • Period : since 2017, December

For more information see venus.cnes.fr

Level

Level 1 : Single date product, Top Of Amosphere (TOA) reflectances, calibrated and geocoded.

Level 2 : Single date product, surface reflectances after cloud masking and atmospheric correction. 

Level 3 : Multidate product, synthesis of cloud free pixels from the level 2 products acquired during a small period of time, it will be produced every 15 days.

Product format

Level 1

A simplistic description of the Venµs data is given here.

More information on geometric quality is available in pdf format or on the following website.

Further information on solar irradiance and the Earth-Sun distance of L1 metadata is available here.

The spectral characteristics of the Venµs camera are detailed here.

Level 2

Level 2A products provide atmospheric corrected surface reflectances and are supplied with a cloud mask and shadows.

Data processing is performed with the MAJA chain (formerly called MACCS) on behalf of the Theia data center.

MAJA Algorithm Theoretical Basis Document (ATBD)