The Study Of The Ranging Lidar Based On Acousto-optic Correlator On The Theory And Experiment

Ranging lidar system has a good effect on resolution, but the ranging coverage oflidar cannot compare with microwave radar. The ranging coverage of radar can reach toa hundred kilometers, however the ranging coverage of lidar cannot be over10kms. Theranging coverage of imaging lidar is even short, less than4km. It has already becomethe bottleneck of lidar. In the search of long distance, the pulse compressiontechnique was used in microwave radar, with the acousto-optic correlator, to improvethe peak power of the signal and enhance the ranging coverage. In this paper, theacousto-optic correlator is used in ranging lidar system, measuring the time of the returnsignal in the way of correlating. A new way of lidar ranging, based on the acousto-opticcorrelator, is designed. The theory analysis and experimental research is made to studythe function of this system.The research background on the ranging lidar system is introduced, listing thetechnical features of different kinds of lidar system. The pulse compression techniqueand the development of acousto-optic correlator are also induced in this paper.Two ways of lidar ranging are analyzed, summarizing the points on lidar ranging. Theprinciple of operation on acousto-optic correlator is studied. At last, we get a conclusionthat acousto-optic correlator can be used in the measuring of delay time, to get thedistance of target.The ranging lidar system based on the acousto-optic correlator is designed, and theprinciple of operation is studied. With the analysis in frequency domain, we proved thatthere is a peak carrying the information of distance. The inflection pattern is calculatedwith the model of the Fraunhofer. The relationship of the position of the peak and thedistance of the target is found. The function of this system is studied on the resolutionand the range. We analyze the influence of the size of the inflection pattern to resolution.With the result on the function, the practicability of the system is proved. With a similarresolution, A higher distance can be detected in this way.A platform of the system is made to check the result of analysis. The scanningperformance is tested, and the independence of acousto-optic raster is checked. Aexperiment of the parallel signal measuring is made, the result which can prove therationality of this design. Using a electric delay to simulate the distance, the relationshipof the position of the peak and the distance of the target. The result can square with thetheory.In this paper, A new system of the ranging lidar is designed. The measuring ofdistance is achieved with the instrument we can get. It is a way of intensity of light,which is showed by the position of the correlating peak. With a similar resolution oftraditional ways, A higher distance can be detected in this way. At last, the theory andthe result can be proved by an experiment.