EXTENDED TARGET DETECTION WITH EMPHASIS ON ACOUSTIC SURVEILLANCE. VOLUME VI. ACCURACY OF ESTIMATION IN QUADRATIC PROCESSORS,
Abstract
General equations in integral form are derived for the mean square error of the delay estimate and for the doppler shift estimate in quadratic processing. These integral expressions are used to obtain algebraic results for the contributions to the mean square error of the two estimates arising from ambient noise alone and from reverberation alone for either monochromatic pulses or linearly swept FM pulses returned from a fluctuating extended target. Gaussian shapes were assumed for the signal envelope, for the reverberation power density spectrum, and for the description of the target extent and fluctuation. The doppler estimate has a bias caused by reverberation alone, whereas the delay estimate is unbiased. Similar results are obtained for the delay estimate of the modified Sussman combiner processing monochromatic pulses or linearly swept FM pulses returned from a slowly fluctuating extended target. The interaction of signal with ambient noise and reverberation causes a bias arising from the asymmetry of the impulse response of the output RC integrator of the combiner. The contributions to the mean square error of the delay estimate from ambient noise alone and from reverberation alone are also found for this processor.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 16, 1967
- Accession Number
- AD0822900
Entities
People
- Burton S. Abrams
- Harry Urkowitz