The key of time difference location is to extract time difference with high precision.Due to the complexity of ionosphere,the traditional time difference estimation algorithm based on cross correlation can-not extract the time delay information of short wave signal,in this paper,the ionospheric electron density information is obtained by using the international reference ionospheric model,the Vogler channel model is constructed by using the numerical ray tracing method,and the time delay estimation of shortwave signal is obtained.The Cramer-Rao lower bound(CRLB)of shortwave time difference measurement is derived un-der the background that the signal correlation is not affected by Doppler extension.The simulation results show that CRLB is related to sampling time,radio frequency and input signal-to-noise ratio,and the CRLB of time difference measurement in winter is lower than that in summer.
关键词
Vogler信道/短波时差测量/多普勒扩展/克拉美罗界
Key words
Vogler channel/shortwave time difference measurement/Doppler extension/Cramer-Rao lower bound
维普
万方数据