VisioTerra carries out studies on various subjects ranging from the evaluation of products from data producers (mainly space agencies) to more thematic subjects such as studies of the evolution of land use, deforestation, extension of urban areas, analysis in structural geology and hydrogeology, environmental impact, estimation of pollution...

Product evaluation allows space agencies to assess the quality of a product with respect to external references, to compare products between them and to quantify the suitability for use for different applications. The study carried out for ESA consisted of evaluating the accuracy of the heights provided by the SRTM, ASTER GDEM, ALOS World 3D and Copernicus DEMs DTMs compared to the ICESat LiDAR data. The DTMs were compared to each other by calculating the difference between two DTMs on the fly. Their usability was measured by comparing the orthorectification results from the same scene but using two different DTMs. The study carried out for the CNES allowed to verify the access to several scenes among the 150,000 produced, their processing on the fly, the results of the pseudo "natural colors" color composition and to produce a gallery of hyperlooks of SPOT-123, SPOT-4 and SPOT-5 scenes.

Thematic studies are commissioned by United Nations agencies or NGOs. The aim is to establish a baseline at a given time or to analyze the evolution of the land cover over time by producing maps at regular intervals. In both cases, the user provides the nomenclature of the desired classes.


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