Probability of Detection for a Go CFAR Radar Processor Using Envelope Detection Approximation
Abstract
The greatest-of logic for a constant false alarm rate processor (GO CFAR) is a commonly used method for the adaptive setting of a radar detection threshold in the presence of clutter edges. Instead of using a true envelope detector x = I2 + Q2, which is difficult to implement, envelope detection approximations of the form Xe = aMax (I),(Q) + bMin (I),(Q) and xe = a(I)+b(Q) (no Max and Min operators) where a and b are constants, are often used to detect a signal decomposed into its in-phase (I) and quadrature (Q) components. Closed form expressions are derived for the probability density function (pdf) of a radar range cell containing a detected target signal in the presence of noise using both approximations. These can then be used to calculate the probability of detection (PD). They can also be used to calculate the probability of false alarm (PFA) if the means of I and Q are set to zero. Closed form expressions are obtained analytically and by curve-fitting the numerically derived pdf of the target cell. Finally, using Monte Carlo techniques, this thesis also compares the GO CFAR detection performance using envelope detection approximations xe, xe and the true envelope detector x for zero mean white Gaussian noise input samples I and Q.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1994
- Accession Number
- ADA286211
Entities
People
- Joseph J. Hache
Organizations
- Naval Postgraduate School