What is the modulation transfer function for astronaut-acquired images?
By including a modulation transfer function (MTF) for a remote sensing system you get a more realistic approximation of how well that system can distinguish objects of various widths than you get from a simple calculation of instantaneous field of view (IFOV). For example, it is sometimes said that when the MTF is included Landsat TM resolution changes from 30 m to 60 m. However, the resulting larger “resolution” number you get is still an underestimate of ground resolved distance for many purposes. One could calculate MTF for a photographic remote sensing system from the direction of lens distortion at given distances and other parameters such as ground smear, etc. For handheld photographs by astronauts, however, there are many uncontrolled variables that have a greater influence on resolution (like look angle and window distortion) so no one has ever developed a set of MTFs.
