The orbits and associated temporal/spatial coverages of polar-orbiting meteorological satellites have important implications for the operational application of NOAA and DMSP microwave imagery and products. Since products are currently available to the operational community from both NOAA and DMSP, the module covers the similarities as well as key differences between the two satellite systems. The composite image of total precipitable water (TPW) shows the differences in coverage between the AMSU and SSM/I, illustrated by the difference in the gaps between passes.