Method and device for airborne laser scanning flying height change real-time compensation

Abstract

A method and a device for airborne laser scanning flying height change real-time compensation can eliminate adverse effect of flying height change to a laser scanning point cloud distribution area and cloud density of a laser scanning point. When the flying height of an airborne platform is changed, a flying height change value is acquired by a global position system(GPS) / inertial navigation system(INS)integrated measurement device, the value of a scan field angle which can keep the width of a scanning stripe unchanged and the value of a laser pulse frequency which can keep the laser scanning point cloud density unchanged are calculated in a flying height compensation controller. A rotating prism photoelectric shaft angle encoder measures and obtains a real time rotating angle of a rotating prism and offers the real time rotating angle of the rotating prism to the flying height compensation controller, a square signal which is identical with an expect laser pulse frequency value is outputted only within a scope of the required scan field angle and offered to a laser pulse transmitter, thus a laser transmitter can launch a laser pulse of the corresponding frequency. By using the compensation method, the flying height change of the airborne platform can not affect the laser scanning point cloud distribution area and cloud density of a laser scanning point permanently.

Description

technical field [0001] The invention relates to the compensation problem of the flying height change of the point-scanning three-dimensional imaging airborne laser radar. Background technique [0002] Airborne lidar is a terrain mapping technology based on the principle of laser ranging, which integrates aircraft platforms, laser scanners, differential global positioning system DGPS (Differential Global Positioning System), inertial navigation system INS (Initial Navigation System) and computer data acquisition and processing system, etc. [0003] The working process of the airborne lidar is as follows: the aircraft flies in a straight line at a constant speed on a preset flight route, and the flight altitude is planned in advance. In the local horizontal plane reference coordinate system, the ideal flight altitude is unchanged. The track and attitude angle of the laser scanner load platform are measured in real time by the DGPS / INS combined measurement system through Kalma...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the defect that the existing measurement technology of the above-mentioned airborne laser radar system cannot compensate the change of flight height, the present invention provides a method and device for real-time compensation of flight height change of airborne laser scanning. The purpose of its realization is that when the flight height When changing in real time, the scan bandwidth and laser point density of the airborne lidar's ground-scanning laser point cloud remain constant

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