Ground Test Equipment Design For Spaceborne Image Compression System

With the rapid development of image compression technology,image compression coding technology is increasingly applied to the field of satellite detection.In view of the characteristics of satellite detection task including long working cycle,high risk and high cost,the testing to the spaceborne image compression system completed on the ground is of great importance.As the real space camera is inconvenient to utilize because of its high cost and long development cycle,in order to ensure the development and testing of image compression system effectively carried out and solve the problem of system validation in the development and testing of spaceborne image compression system,it is increasingly important to design a set of related test equipment to solve the problem of system verification in the development and commissioning phase of the spaceborne image compression system.First,this paper expounds the key role of testing in each stage of the development and exploitation of the project,summarizes the core principles and basic process of the testing,also introduces the design approach and the actual testing method of the test cases in the project test,which lay a theoretical foundation for the integration validation testing of the spaceborne image compression system.Further,the spaceborne image compression system is illustrated;the requirements of the Earth equipment are analyzed according to the characteristics of the matched spaceborne image compression system;the functions and performance indicators of the terrestrial test equipment are summarized;and the overall structure of the terrestrial test equipment is divided into hardware and software.On the basis of the above theories,this paper,with reference to the previous project experience and the specific development requirements of the selected device,focuses on the design and improvement of the hardware design part of the terrestrial test equipment.The hardware circuit of the terrestrial test equipment uses the Zynq-7000 series development board introduced by Xilinx Company as the core control unit,calls the external high-speed dynamic data memory based on DDR3,and realizes the precise transmission control of the image data from two cameras and the collection & recovery of the compressed code stream.At the same time,the terrestrial test equipment also simulates the abnormal phenomena of the space camera such as the image frame lost and the signal event effect that may appear in the space single particle radiation environment,which remedy the lack of effective anomaly test for space camera.In addition,because of the configurability of the hardware circuit,the selected device has a strong versatility,and can be used to test different compression systems after simple modification to the device interface.Finally,according to the testing plan of the spaceborne image compression system,this paper introduces the integration validation testing of the system.The main process is to control the terrestrial test equipment by the host computer to simulate the camera to output image data which is transmitted in the form of LVDS differential signal to the spaceborne image compression system for processing.Then the processed compressed code stream is collected to the host computer of the terrestrial test equipment for storage verification.This paper performs the testing item by item based on the test case,finally completes the effective validation of the spaceborne image compression system in terms of function,performance,interface and reliability.The whole equipment is simple in structure,complete in function,strong in integrity and high in automation,and it is of great significance in assisting the completion of the development of the spaceborne image compression system.