Joint estimation of time delay and Doppler ratio from broadband data using discrete estimation techniques

An innovative technique to detect and track a target that radiates predominantly broadband energy is presented. The signal is modeled as a broadband Gaussian process that is observed on two spatially distributed sensors. The noise at each sensor is assumed to be an independent, additive Gaussian process. The time series data observed at the sensors depends on both target Doppler and time delay. This study modeled both Doppler and time delay, using a discrete two-dimensional probability density function (PDF) to describe the statistical behavior of Doppler and time delay. Joint estimation of both parameters improves the signal-to-noise ratio at the output of the receiver, and therefore provides a more reliable estimate of differential time delay than if Doppler were ignored