Self-driving cars aren’t as far off as they seem, and with advancements in modern technology, it will only be a matter of time. The question that plagues most people’s mind is how do these cars see? They do so by using LIDAR surveying and photogrammetry.
What Is LIDAR and Photogrammetry?
LIDAR stands for Light Detection and Ranging and is the process of using a laser to measure variable distances to Earth. The laser “scans” the ground and structural components on it to provide accurate 3D information about the surfaces. Data collected is either topographical or bathymetric.Topographical lasers are almost infrared and are used to scan the different elevations and structures as stated above. Bathymetric lasers are green and are used to penetrate water for seabed mapping. Usually, LIDAR is equipped on aircraft and shot aerially to allow for a vertical shot angle from a high altitude. Planes and helicopters are commonly used for LIDAR mapping. LIDAR technology is commonly by a civil engineering company to assess structures, roads, watersheds, etc.
Photogrammetry is the science of using still frame 2D photos to generate maps or 3D models of surface structures, man-made or naturally occurring. There are two types of photogrammetry: Aerial, and Terrestrial and Close-Range. Drones fly over a path in aerial photogrammetry and take overlapping shots of the area; this is commonly used in topographical data collection. Terrestrial photogrammetry refers to when the camera is on the ground and provides three-dimensional data and drawings of things such as buildings, engineering structures, earth-works, and film-sets.
How They Can Be Used
For many purposes, LIDAR and photogrammetry are used by civil engineers to create structural designs and roadway designs using the precise data collected. Things like transportation infrastructure and watershed engineers also use LIDAR surveying and photogrammetry. However, scientists are using these processes to help design self-driving cars. Approximately over one-third of the major roads in America are considered to be in poor or second-rate, so the cars would need to be able to sense hazardous conditions. The cars will have information about roadways and structures provided by LIDAR data and are also equipped with real-time photogrammetry equipment to gather data such as large potholes, downed telephone lines, and heavy traffic. This also allows autonomous cars to be able to know road conditions ahead of time so the car isn’t relying solely on a 30-meter sensor range. The cars can compare the data from the map provided by the aerial scans against the data collected from the sensors to make “decisions” about road conditions as well.
There are many other applications LIDAR surveying and photogrammetry provides. Not every civil engineering company uses these techniques as well, so the ones who do are able to research and execute projects on a more reputable and efficient scale.