Noise SAR Signal Generation And Data Acquisition

Synthetic aperture radar is a kind of high-resolution microwave imaging radar.It can operate regardless of various weather conditions and timely obtains images of wide region.SAR has been widely used in military and civil fields.The random noise signal radar was noted for its attractive low probability of intercept(LPI),good electronic counter counter-measure(ECCM),good electromagnetic compatibility(EMC)and unambiguous estimation of range.Therefore,random noise synthetic aperture radar can better exert the advantages.In this paper,we study the signal generation and data acquisition of the random noise synthetic aperture radar.In this paper,software and hardware implementation of the system are designed according to the performance requirements and the technical parameters of the wideband noise synthetic aperture radar.Also,the structure block diagram and work flow are given.The bandwidth,resolution and ambiguity function of linear FM signal and noise FM signal are analyzed and simulated.Combined with the hardware platform,this paper deduces the method of parallel DDS(Direct Digital Synthesizer)to produce LFM signal.Also gives the method of linear feedback shift register,the central limit theorem of addition and DDS to generate NFM signal.Based on FPGA platform and combined with high speed digital to analog converter AD9739,wideband LFM signal and LFM signal are generated and eradiated by microwave.At the same time,high-speed ADC 12D 1800 is used to collect the echo data of radar to FPGA.Next,data are stored to the host computer through the high speed transmission interface(PCIE).Finally,the hardware debugging and verification of the whole radar system are carried out.Through processing and analyzing the collected data,the imaging results are obtained and the performance of the radar system is good.And it shows the feasibility of radar signal generation and data acquisition.