Somewhat more sophisticated is the approach that uses each sensor data set as input to classification. The trick to doing meaningful multisensor analysis lies in properly registering a variety of data sets. These data sets may come from sensors mounted on several platforms, which leads to multidimensional data, characterized by different pixel sizes, viewing geometries, orbital or flight line paths, times of year, angles of illumination, etc. Techniques for registering images have evolved over the years. One example superposes multitemporal Landsat data.
Plans are well along for putting hyperspectral remote sensing into space.
Another satellite under development, with launch in the next few years, is OrbView-4, operated by Orbital Imaging Corp .