Study On The Footprints Image Simulation Of Satellite Laser Altimeter

The technology of satellite laser measurement has developed rapidly in recent years.Although it has the high precision of centimeter-level measurement,it still has the problem of poor horizontal precision.And footprints camera carries on the satellite laser altimeter used to improve the horizontal precision of laser altimeter data.It improves pointing accuracy and the horizontal precision of the laser altimeter data,and it can also provide a reference for quality reliability of laser altimeter data.Therefore,it is important to carry out the simulations which research on the image from the footprints camera.In this paper simulation method of the footprints image is mainly based on CCD imaging simulation,after comparing the difference between CMOS and CCD imaging method,this paper puts forward the suitable simulation method for footprints camera application purpose,and obtained the good simulation results.Because the footprints camera doesn't obtain the laser speckle imaging from the ground,in this paper,the shape and energy distribution of laser facula has been simulated under the conditions of different terrain and atmosphere.When the terrain is slope,the eccentricity of the spot will increase with the increase of slope.However,because the slope is very small compared with the height of the satellite,the effect of slope on the center of mass is not obvious.Besides,the laser spot will be broken due to the emergent angle of laser and step topography,the greater the emergent angle of laser and height of step topography,the greater the degree of crushing,which will affect the center of mass of the spot.The atmospheric attenuation and atmospheric turbulence will result in the expansion and deviation of laser speckle,which will eventually lead to the decrease of the horizontal precision of laser elevation data.For a better application of footprints image,this paper puts forward the characteristic parameters which would be required for subsequent processing of footprints image and the method for calculating characteristic parameters,the reliability of proposed method which verified by using the similar data showed good results.