Lidar systems send laser pulses in different directions and detect the reflected light, similar to a radar. Smaller lidar modules are used for range sensing. Complex lidar systems can be used to create extremely detailed 3D topology maps from the air. As opposed to photogrammetry with cameras they can also capture narrow objects such as power lines three dimensionally. Moreover, they are able to see through different layers of vegetation. These characteristics make lidar scanners useful for a range of applications in inspections, civil engineering, archaeology and science.