Estimates are generated from images and other sensor outputs.

The descent image motion estimation system (DIMES) is a system of hardware and software, designed for original use in estimating the horizontal velocity of a spacecraft descending toward a landing on Mars. The estimated horizontal velocity is used in generating rocket-firing commands to reduce the horizontal velocity as part of an overall control scheme to minimize the landing impact. DIMES can also be used for estimating the horizontal velocity of a remotely controlled or autonomous aircraft for purposes of navigation and control.

The DIMES Algorithm fuses images of terrain below with IMU data and radar-altimeter readings toestimate horizontal velocity.

The DIMES sensors include a descent imager (an electronic camera that acquires images of the approaching terrain), a radar altimeter, and an inertial measurement unit (IMU). The DIMES flight software implements an algorithm for combining measurement data from the aforementioned sensors to estimate horizontal velocity.