Laser rangefinder is an automatic remote sensing technology that measures the distance between the sensor and the policy object through the laser announced by the sensor (laser radar). According to different exploration policies, this technology can be divided into two types: air exploration and land exploration. Air-to-air laser ranging aims at ending the measurement of atmospheric physical and chemical properties by emitting laser beams into the air and receiving echoes reflected by suspended particles in the air. The primary policy of laser ranging to the ground is to obtain surface information such as geology, topography, geomorphology and land use. According to the classification of sensor carrying channels, laser ranging can be divided into four categories: on-board (satellite carrying), on-board (airplane carrying), on-board (automobile carrying) and positioning (fixed point measurement).

Laser ranging technology began in the sixties of the 20th century. By the seventies and eighties, laser technology has now become an important component of electronic ranging equipment. LIDAR(Light Detection And Ranging) generally refers to airborne ground-to-ground laser ranging technology, and the Chinese term commonly refers to LIDAR instead. In the United States, since the seventies of the last century, several organizations including NASA, NOAA and DMA have initially opened LIDAR sensors for ocean and terrain measurements. In Europe, the research on laser ranging started almost together with the United States. What is different from the United States is that they are committed to opening up the satellite channel laser ranging radar system, focusing more on the development and research of the airborne channel and its matching laser radar system, and have achieved considerable success.

In the nineties of the last century, with the opening of airborne GPS technology and portable accounting machine system, the stability and accuracy of LIDAR system have been greatly advanced, and gradually put into commercial application in Europe, and the related application research has also been opened in Europe first.

Related to other remote sensing technologies, the research on LIDAR is a very new field. Whether it is in the accuracy and quality of moving LIDAR data or in the application technology of rich LIDAR data, the research is quite vivid. Different from the remote sensing impression technology, LIDAR system can sensitively acquire the three-dimensional geographic coordinate information of the surface and corresponding ground objects (trees, buildings, surface, etc.) on the surface, and its three-dimensional characteristics meet the research needs of the mainstream of the digital earth today.

With the continuous development of LIDAR sensors, the gradual development of surface sampling point density and the increase of recoverable wave number of single laser beam, LIDAR data will provide more abundant surface and ground features information. Filtering, interpolating, classifying and segmenting the three-dimensional point sets collected by LIDAR can obtain various high-precision three-dimensional digital ground models, classify and identify surface features and finish the three-dimensional digital reconstruction of surface features such as trees and buildings, and even manufacture three-dimensional forest and three-dimensional city models to construct virtual reality. On the basis of virtual reality, more precise ground feature analysis can be carried out to estimate various parameters of forest land and its individual tree, and then the management of precision forestry and agriculture can be completed. The city planning, city environment and city climate can be modeled and analyzed to end the evaluation and control of sound, light and environmental pollution.