General Method Of Multiple Mode Spaceborne SAR Raw Data Simulation

Spaceborne Synthetic Aperture Radar(SAR)is a earth observation system that is mounted on a satellite platform and uses synthetic aperture theory to achieve high-resolution microwave imaging.Due to its all-day,all-weather,and certain ability to penetrate the surface,it has a wide range of applications in military and civilian fields.With the development of science and technology and the increase in demand,spaceborne SAR is developing toward multi-mode,multi-polarity,and high-efficiency.In order to support the normal operation of spaceborne SAR ground processing systems,it is bound to put higher demands on the spaceborne SAR raw data simulation system.While ensuring that the spaceborne SAR raw data simulation system satisfies the actual system operating characteristics,it also requires that it be capable of reality and high efficiency.Therefore,it has brought the design of spaceborne SAR echo simulation system great challenges.This paper proposes a general simulation method for multi-mode spaceborne SAR echo system.By introducing the basic technologies of spaceborne SAR,the operational characteristics of the spaceborne SAR echo system are demonstrated.Then it elaborates the working characteristics of spaceborne SAR under different working modes,and uses its commonality to unify multiple modes into one system.By improving the relevant algorithms,the performance of the system is improved by the parallel architecture.By introducing a variety of real system errors,the reality of the simulation is improved.Firstly,the basic techniques of low orbit spaceborne SAR are studied.The four aspects of satellite platform modeling,target modeling,payload modeling,and astronomical geometry modeling are introduced,which present the basic characteristics of multi-mode spaceborne SAR.Secondly,by consulting a large number of documents,the key technologies related to the echo simulation of geosynchronous orbiting spaceborne SAR are studied.By comparing the different characteristics of low-orbit and geosynchronous orbit space-borne SAR,the geosynchronous orbital spaceborne SAR raw data simulation technology is studied.The two aspects of orbit modeling,slant range modeling and ambiguity modeling are introduced in detail.Last but not least,a multi-mode spaceborne SAR raw data generation model is established by means of the range frequency domain pulse coherence method.In order to reflect the reality,the ambiguity modeling is introduced to the simulation.The general simulation method proposed in this paper has been transplanted into two simulation systems for verification.One is a multi-mode spaceborne SAR raw data simulation system designed based on a ground computing platform.Experiments show that the system can effectively simulate raw data of multiple working modes.The other is based on mobile GPU computing platform designed for real-time imaging of spaceborne SAR echo simulation verification system.The experiments validate its effectiveness and prove its real-time characteristics,laying the foundation for future research on the development of spaceborne SAR technology.