LIDAR (Light Detection and Ranging) is a device that can measure distance or particle density of air by shining a light (LASER) through it.
Light from the LIDAR is reflected away from an object, or objects, by a phenomenon called backscattering, which can indicate abundance of particles, types of compounds available, temperature and height of the particles.
However, LIDAR backscattering is incapable of discriminating between types of particles in a single image, so a LIDAR image may be indicating frost, with ice suspended ice particles (stardust) or an approaching dust storm (dust or sand particles).
IDAR image of approaching fog front on Mars. The cooler colours: blue, aqua and green represent low particle density, the warmer colours: yellow, orange and red represent high particle density.