LIght Detection And Ranging (LIDAR) is an active remote sensing technology, similar to radar, that transmits laser pulses to a target and records the time it takes for the pulse to return to the sensor receiver. This technology is currently being used for high-resolution topographic mapping by mounting a LIDAR sensor, integrated with Global Positioning System (GPS) and Inertial Measurement Unit (IMU) technology, to the bottom of aircraft and measuring the pulse return rate to determine surface elevations.

The primary difference between LIDAR and radar is that with LIDAR, much shorter wavelengths of the electromagnetic spectrum are used, typically in the ultraviolet, visible, or near infrared. In general it is possible to image a feature or object only about the same size as the wavelength, or larger. Thus LIDAR is highly sensitive to aerosols and cloud particles and has many applications in atmospheric research and meteorology. For specific details regarding LIDAR data at NSIDC, please refer to the instrument descriptions below.

GLAS: The main objective of the GLAS instrument is to measure ice sheet elevations and changes in elevation through time. Secondary objectives include measurement of cloud and aerosol height profiles, land elevation and vegetation cover, and sea ice thickness. These data will enable scientists to study the Earth's climate, and ultimately predict how ice sheets and sea level will respond to future climate change.