Traditional direct cross-correlation for time delay estimation has a poor performance when SNR is low, and doesn t satisfy the demand of high resolution estimation.

Real-time & high accuracy TDOA estimation method for tracking fast moving target;

TDOA estimation of the spread spectrum communication signals based on cycle spectral correlation;

This paper studies the TDOA estimation method using the characteristics of cycle stationary communication signal.

Algorithm based on cumulant for joint estimation of TDOA/FDOA;

The key technology of it is passive ranging, while the key of ranging is the high precise time delay estimation, which is the main factor that restricts the precision of ranging.