The Study Of Identification Method Of Laser Direction For SLR In Daytime Based On CCD

In day-time Satellite laser ranging,the direction of the laser identified not only can effectively improve the success rate of the daytime observations,increase the total amount of observation data,improve data accuracy and also can help realize observation stations unattended observe.Strong background noise is one of the main factors influencing the direction of laser identification during the day-time,which comes mainly from atmospheric scattering of sunlight,refraction,etc.Based on the high performance CCD camera-PCO.1600,combined with the time filtering technology,spectral filtering technology can effectively reduce the background noise of the camera.Though the processing of the images,the contrast between the laser beam and the background is improved,which makes it possible to identify the laser direction during the day-time.Aiming at high laser pulse frequency and pulse duration is short,this article using FPGA constructs a laser controller.The CCD,which has an external trigger function,synchronously working with laser device under the control of the controller,realized the purpose of temporal filtering.Spectral filtering is based on the laser line width is very narrow and good monochromaticity,using narrow band filter to separate the light from the background noise of a specific wavelength.The image processing results of the gray linear enhancement,histogram equalization and histogram are discussed in details.In this paper,the background noise suppression methods are studied,the ideas and methods to solve the problem were put forward,results of experiment and experiment of processing to original image showed good results,which lays a foundation for further experimental research.