Design And Application Of Electric Chaotic Radar Ranging System Based On Virtual Instrument

Broadband chaotic signal has the advantages of noise-like, aperiodicity, autocorrelation curve similar to δ function curve and high frequency, so when applied in the study of spatial distance, it has strong anti-interference ability and high spatial resolution. The following questions always arise in the actual measurement experiments with the broadband chaotic signal generated by the circuit board:firstly, debugging of the system takes a long time; secondly, chaotic signal is affected by the parasitic capacitance of the circuit and its frequency is not adjustable, so chaotic radar can only realize monotonous detection. With the development of virtual instrument technology and digital technology, digital system producing chaotic signal becomes a new development trend. Virtual instrument can produce a variety of chaotic signals which can be used as the detection signal source to achieve many. measurement such as ranging, exploration, etc, and it can be used to have a comprehensive data analysis.In this paper, Colpitts chaotic signal based on Lab VIEW is produced and the electric chaotic radar ranging system with virtual instrument is built. The main work arrangement is as follows:Firstly, in order to make sure that the detection signal of the virtual radar system is fine and stable, a steady and reliable Colpitts chaotic signal source is selected, then, its differential equation and the influence of different parameters on the differential equation are analyzed.Secondly, electric Colpitts chaotic signal is generated by virtual platform with MATLAB calculation module combined with data acquisition card and high speed DAC (digital to analog converter), then, it’s used to achieve output, measurement and acquisition. The fundamental frequency of the Colpitts chaotic signal generated is240MHz, and the peak-to-peak voltage is about100mV.Thirdly, this paper builds an electric chaotic radar system based on Lab VIEW, produces a Colpitts chaotic signal generated by LabVIEW, which is used to be the signal source of the radar ranging system, then, designs a complete electrical chaotic radar ranging system used for spatial ranging with the LabVIEW feature in data acquisition.Finally, data analysis based on LabVIEW platform. Electric chaotic radar ranging system is used to realize the distance measurement of the measured target with the relative time delay corresponding to the peak of the correlation curve between detection signal and the echo signal reflected by the measured target, therefore, the collation and analysis of the final data is a very important work. Virtual instrument, which can achieve multiple data processing in a same window, greatly reduces the time for data analysis.Experiment shows that this system has the advantages of simple operation, high measurement accuracy, timeliness and so on. This system also effectively solves the requirements of chaotic radar in real-time. The farthest distance measurement of the experiment is about7.3m and the spatial resolution is8cm. In the experiment, due to the limitation of the chaos generated by Lab VIEW, the detection signals will submerge in noise when the system measures the longer distance, at the same time, data processing algorithm of distance measurement needs further research to improve.