Measurement of the sensor spatial response for remote sensing systems

An important aspect of long-term earth remote sensing missions, such as NASA's Earth Observing System, is characterization and monitoring of the sensor performance over the lifetime of the mission, which can be many years. Emphasis has traditionally been placed on the sensor radiometric response, but the spatial response is equally important for inter-sensor comparisons, accurate spatial pixel aggregation, and spectral signal unmixing. In this paper, I present a review of techniques for sensor spatial response measurement from operational imagery and contrast their relative advantages and disadvantages. Examples of spatial response and MTF measurement from airborne and satellite sensors are presented, and the sensitivity of different techniques to aliasing and noise and their requirements for target calibration are discussed.