Research High-precision Measurement Of Doppler In Passive Location By Single Satellite

This topic mainly research high-precision measurement of Doppler in passive locationby single satellite. In the case of space borne platforms, satellite receiver receives thesignal energy is weak, and With low probability of intercept (LPI) signals wide application,further increasing the signal receiver signal analysis, the ability to extract the signalparameters。In the single satellite locating system signal from the Doppler informationprecision made to ensure high positioning accuracy, at low SNR, how to accurate estimateof the Doppler signals become today an urgent need to solve the problem.In the single satellite locating system, as observation parameter vector of the targetsignal, its types and forms are varied and often unknown; The target signal mostly veryshort duration pulses by a single pulse signal is difficult to get accurate parameterestimation; Most of the target signal is short duration pulses, by a single pulse signal isdifficult to obtain accurate estimation of parameters; Doppler frequency rate-of-changeparameter caused by radial acceleration is more subtle, typically100Hz/s magnitude, In thepulse signals having a phase modulation, the doppler will combine with the unknownmodulation parameters together, increasing the difficulty of the measurement; Thereceived signal is relative weakand the SNR is very low. These features of target signalmake the traditional parameter estimation method’s accuracy decline greatly. it makes senseto propose correct and effective method of measuring doppler information according to thecharacteristics of different signals.according to the above characteristics of the target signal, This paper improved thetraditional signal model and measurement methods, extracted doppler information from thetime domain,frequency domain and time-frequency combined domain as well, This articlemain research content:Chapter2researches the single location system based on the kinematics convertesacceleration parameters of positioning to doppler time information and doppler frequencyinformation, and respectively analyzed the time of Doppler and frequency of Doppler effecton location. Chapter3researches the measurement of doppler information in frequency domain,establishes signal model and the corresponding coherent integration algorithm to estimatethe doppler frequency rate of change for sinusoidal signals, chirp signal and three phasesignals, and simulates in different conditions.Chapter4researches the measurement of doppler information in time domain,hasimproved autocorrelation accumulation algorithm and completed a rough estimate of TOA,then uses fractional delay estimation algorithm solves problem caused by mismatchbetween pulse repetition interval and sampling period.Chapter4also joints frequency-domain and time-domain,uses matched filteringtechnology to further improve the estimation accuracy of doppler information.