glossary

some terminology

geotiff - tiff of geo data
remote sensing - satellite images
ortho-rectification - process of lining up images to a base map, and correcting distortion
nadir angle - how far off the satellite is from normal to the earth's surface
UTM - universal transverse mercator
UDM - usable data map. A mask that shows where clouds are etc
DEM - digital elevation map - the height of any place on Earth

Sources