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Instantaneous polarization match: Identifies amplitude changes due to anomalous polarization in GPR data
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Fifth International Conferention on Ground Penetrating Radar, Jun 1994, cp-300-00008
Abstract
Instantaneous polarization match identifies amplitude anomalies due to the altering of wavelet polarization by an interface or the intervening medium. The match factor (p) varies from 0.0 to 1.0 for cross and parallel polarization, respectively, thereby scaling the antenna's effective aperture and thus the received power via the radar equation. Polarization match is defined mathematically from the dot. product of antenna and wavelet polarizations. Calculation of p requires two component data, i.e. transmit and receive antennas parallel (E=) and perpendicular (E.i)' Assumptions regarding the antennas were minimized by using a general equation containing antenna polarization terms which we estimated from a lake bottom reflection. The uncertainty in p values arises primarily from random noise and timing errors. Due to inherent variations in noise level, the standard deviation varies from about 0.06 for low matches (< ~ 0.35), rising at middle match values to about 0.065, then decreasing to about 0.015 at matches greater than 0.95.``