Fast Envelope Correlation for Passive Ranging
Abstract
Application of classic triangulation methods will allow the location of a radar to be determined by passive sensors. Through the use of modern digital signal processing techniques this estimate can be made in a simpler fashion using a conventional receiver. In this thesis a technique is developed for time difference of arrival (TDOA) estimation using a frequency domain based correlation detector driven by an envelope detector. Time lag boundaries are defined on the output of the correlator. A fixed detection threshold is calculated to permit constant false alarm rate (CFAR) detection. The performance of the correlation detector is plotted as a receiver operating characteristic (ROC) curve as a function of signal to noise ratio (SNR). An interactive MATLAB software program is provided to perform either spectral domain or time domain based correlation. Spectral domain based correlation uses the Fast Fourier Transform (FFT). Implicit with the use of FFT are finite arithmetic internal processing errors which are modeled as independent uncorrelated noise sources. A method is presented to account for SNR degradation at the output of the FFT.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1991
- Accession Number
- ADA246333
Entities
People
- Frank J. Mika
Organizations
- Naval Postgraduate School