On the basis of the existing research, the passive detection method based
on Doppler shift is further converted to the passive detection method based on the
non-fuzzy phase difference measurement. Based on the phase-frequency conversion,
the passive detection methods of two different models, that is a method of detecting
a fixed target by a moving station, are presented in this chapter for improving the
ranging accuracy. The first one studies the single station passive ranging method
which takes the motion trajectory as the baseline of the detection array. The second
one studies the ranging method which transforms the single base array into the virtual
double base array by the relation between frequency shift and path difference. The
research in this chapter provides some reference information on how to improve the
performance of single or dual station passive positioning. This chapter proves that the
accuracy of the phase difference ranging is better than that of the Doppler frequency
difference. The significance of phase-frequency conversion lies in the first use of
Doppler positioning method to give the location method which is difficult to obtain
by using the phase difference equation, and then through phase-frequency conversion,
further obtain better measurement accuracy than Doppler frequency difference
measurement.
Keywords: Motion trajectory, Phase-frequency conversion, Single station passive ranging, Doppler rate, Short baseline array, Virtual double-basis linear array, Airborne passive positioning, DF, Frequency difference, Path difference, Doppler shift.