Research And Realization Of TACAN Bearing And Distance Measurement Technology

In everyday life,navigation is widely used in many fields and it is playing a significant role in the national economy as well as modern science and technology.TACAN is a tactical air navigation system,which is also a short-range navigation system.The functions of TACAN are ranging,position finding and beacon identify.This paper mainly researched on the ranging and position finding techniques.Firstly,it was an overview of TACAN,which included evolution and research actuality of itself.The goals and the significance of this paper were elaborated as well.Secondly,this paper introduced the principle of ranging and position finding.After that,programming platforms such as VS2013 and matlab were used to realize the simulation.The land beacon and airborne equipment send signals according to a strict set of rules.They used band-pass filtering and envelope demodulation to receive signals.Besides,Gaussian pulse in baseband was identified as rectangular pulse by delaying and comparing methods.Based on the original decode technology,the improved decode technology increased the productivity of decoding.The identity of the main reference-pulse flag and the aid reference-pulse flag algorithm,which was introduced clearly as well as the algorithm of extraction of the 15Hz-135 Hz mixed envelope.The postprocessing of location data algorithm solved the problems of singular value and pointing instability around 0 degrees in noisy background.Thirdly,by simulating the position finding function of TACAN,constantly switching the three states of searching,tracking and memory,the function of distance measurement could be completed.Finally,the TACAN system transmitting and receiving signal processing could be realized in the ISE hardware integration environment.Modelsim simulation platform was used to verify the correctness of the signal,test the input location data and give the simulation results.