Data from the two MODIS instruments have been accurately geolocated (Earth located) to enable retrieval of global
geophysical parameters. The authors describe the approach used to geolocate with sub-pixel accuracy over nine
years of data from MODIS on NASA's EOS Terra spacecraft and seven years of data from MODIS on the Aqua
spacecraft. The approach uses a geometric model of the MODIS instruments, accurate navigation (orbit and
attitude) data and an accurate Earth terrain model to compute the location of each MODIS pixel. The error analysis
approach automatically matches MODIS imagery with a global set of over 1,000 ground control points from the
finer-resolution Landsat satellite to measure static biases and trends in the MODIS geometric model parameters.
Both within orbit and yearly thermally induced cyclic variations in the pointing have been found as well as a general