Because of the continually varying spatial resolution and scale of descent images, a wide range of possible processes can potentially be studied under optimal viewing conditions. Descent imaging will also provide good stereo because of the changing geometry from frame to frame, and therefore can be used to determine quantitative morphometry of surface features. The highest-resolution descent images, taken shortly before landing, will provide a detailed map of the terrain around each Lander. It is mounted on the Lander footpad, and has a clear view of the terrain below the Lander during the entire period from parachute deployment to touch-down. Exposure time is kept very short to prevent significant image smear.
Image resolution improves by about a factor of two from one image to the next.
The total number of images depends on the duration of the Lander atmospheric descent for each site.