US: A new breed of LiDAR technology is being developed and tested by the US Air Force at a base in Massachusetts. This system is capable of precisely mapping over 300 sq km from the belly of an airplane in about half an hour. While it is considerably more advanced than consumer models, the new Air Force LIDAR works on the same basic principle — laser light is projected toward the target, and a sensor detects the photons upon their return. The time it takes is used to calculate the distance, to varying degrees of accuracy. In advanced systems like those used by the military, LiDAR can create a topographic map of the area it is pointed at.
The Air Force system makes the process a snap by packing an unprecedented number of single-photon pixels detectors into the microchip at the core of the unit. The key to the LiDAR’s incredible speed and resolution is semiconductor technology based on indium gallium arsenide (InGaAs). These III-V semiconductors (so-called because they are made from metals in periodic groups III and V) are seen as a potential replacement for silicon in numerous applications. In this case, InGaAs semiconductors operate in the infrared spectrum, which allows for the use of longer wavelengths of light that can travel farther and scan wider areas.