Geometric and radiometric evaluation of remote sensing information in virtual platforms

Abstract

Currently, metadata lack information regarding processing in virtual platforms leading to data quality concerns. Assuming that a search for the same information in different platforms does not present the same result, our objective was to investigate the geometric and radiometric difference between Google Earth Engine (GEE), Sample Extraction Analysis Application (AppEEARS), and Temporal Vegetation Analysis System (SATVeg). Three scenes (H11V09, H12V10 and H13V11) were evaluated for the EVI image of the product MOD13Q1, in which samples were extracted for the SATVeg, GEE and AppEEARS platforms, and the reference image was obtained in original HDF files. The comparison was conducted if the images obtained on the platforms contained the same spatial resolution and radiometric value in relation to the reference image. To determine if the divergences persisted, even if another image projection was adopted, the same methods were used for the geographical projection (EPSG: 4326) and the sinusoidal projection (EPSG: 100,000). Duplicate radiometric value pixels and geometric and radiometric divergence were identified in all platforms when using the geographical projection in the data. The sinusoidal projection was not used to find such divergences. The differences found may have an impact on point evaluations if evaluated in different platforms a divergence in point searches where there may be a change in interpretation depending on the consulted platform. The effective application of these tools is necessary to determine the reliability of this information and to guide the users.