Written by Leandro Gonzalez
Agency/Company Operating the Sensor
Belgian Verhaert Consortium, supported by the European Space Agency (ESA)
The Compact High Resolution Imaging Spectrometer (CHRIS) is a sensor located on board of the Project for On Board Autonomy (PROBA) satellite. This satellite was launched on October 22nd 2001 by ESA. The number of bands in the sensor can be modified. CHRIS can acquire data at 19 bands and a spatial resolution of 18 meters to a 63-band mode with a spatial resolution of 36 meters. In all cases, data are collected in the visible and near infrared areas of the electromagnetic spectrum, more specifically between 410nm and 1050nm. In early February 2012 CHRIS became inactive due to thermal issues. The sensor was reactivated and began to collect data again in early April 2012.
Fourier Transform Hyperspectral Imager (FTHSI), ARIES-1, Hyperion
Toxic sludge in Devecser, Hungary. Copyright ESA, CHRIS Imager, processed by DMCii. Source: Surrey Satellite Technology LTD.
Image of the city of Venice, acquired by the CHRIS (Compact High Resolution Imaging Spectrometer) instrument flown onboard the Proba satellite. Acquired 3 July 2004. Source: ESA.
CHRIS is a unique sensor due to the fact that its spectral resolution can be modified from 19 bands up to 63 bands or channels. As the number of bands increases, the spatial resolution of the imagery decreases (i.e. the greater the number of bands, the bigger the pixel size). The finest spatial resolution produced by CHRIS is 18 meters, while the coarsest spatial resolution reaches 36 meters. Data are only collected in the region of the electromagnetic spectrum comprised between 410nm and 1050 nm. Another important characteristic of this sensor is that CHRIS acquires a set of up to five images of each target during every acquisition sequence.
Image footprint or swath width
14 km (somewhat variable as the altitude varies around the orbit)
PROBA (the satellite containing CHRIS) is in a Sun synchronous orbit, RAAN 10:30. It revisits the same place on Earth approximately every 7 days.
Cost, Acquisition, Licensing
All information regarding CHRIS products is available on the ESA data access website. ESA. The EOLI catalog of ESA offers free data after a user registration form is completed EOLI Catalog. Furthermore, on demand ESA products are made available for free: users shall provide a project proposal for allowing ESA to define a product/programming quota for the project. For information regarding terms and conditions for the utilization of ESA data please visit ESA Registration, terms, and conditions.
CHRIS data can be downloaded on .HDF format.
Examples of Rangeland Uses
Duca R and Del Frate F (2008) explained the advantages of using CHRIS-PROBA for the creation of land cover maps.
Jin HR et al. (2012) performed land cover classification using bitemporal hyperspectral Compact High Resolution Imaging Spectrometer/Project for On Board Autonomy (CHRIS/PROBA) images.
Simic A and Cheng JM (2008) attempted to determine if hyperspectral measurements at multiple angles have much redundancy when extracting crop and soil information.
Verrelst J et al. (2012) looked at estimation of leaf chlorophyll content (Chl), leaf area index, and fractional vegetation cover from space.
Vuolo F et al. (2008) used CHRIS/PROBA data, in both directional and spectral domains, to estimate the Leaf Area Index (LAI)
Imagery analysis software packages such as ERDAS Imagine and ENVI can open .HDF files. Recent versions of ArcGIS (e.g., version 9.3) can read the HDF-EOS format. Alternatively, users can utilize ERDAS Imagine to export .HDF files into .IMG or GeoTIFF formats. Furthermore, tools for carrying out data transformations into other formats and projections can be found at:Data Format Transformations.
• CHRIS website on ESA https://earth.esa.int/web/guest/data-access/browse-data-products/-/asset_publisher/y8Qb/content/proba-chris-level-1a-1488?p_r_p_564233524_assetIdentifier=proba-chris-level-1a-1488&redirect=%2Fc%2Fportal%2Flayout%3Fp_l_id%3D65465
Duca R and Del Frate F. 2008. Hyperspectral and Multiangle CHRIS-PROBA Images for the Generation of Land Cover Maps. In IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING. 46(10): 2857-2866
Jin HR, Li PJ, Cheng T, and Song BQ. 2012. Land cover classification using CHRIS/PROBA images and multi-temporal texture. In International Journal of Remote Sensing. 33(3):101-119
Simic A and Chen JM. 2008. Refining a hyperspectral and multiangle measurement concept for vegetation structure assessment. In CANADIAN JOURNAL OF REMOTE SENSING. 34(3):174-191.
Verrelst J, Alonso L, Camps-Valls G, Delegido J, and Moreno J. 2012. Retrieval of Vegetation Biophysical Parameters Using Gaussian Process Techniques. In IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING. 50(5): 1832-1843
Vuolo F, Dini L, and D’urso G. 2008. Retrieval of Leaf Area Index from CHRIS/PROBA data: an analysis of the directional and spectral information content. In INTERNATIONAL JOURNAL OF REMOTE SENSING. 29 (17-18): 5063-5072.