Repair, Evaluation, Maintenance, and Rehabilitation Research Program: Analysis of a Short Pulse Radar Survey of Revetments Along the Mississippi River.

摘要

A short pulse radar survey was conducted in Mckellar Lake directly across from the US Army Corps of Engineers dock facility at Ensley Engineer Yard. The intent was to examine radar responses to revetments placed on the bottom of the lake to retard erosion and to determine if such responses could be interpreted as indicative of erosion within the revetments themselves. A radar transmitting a pulse with a center frequency of about 60 MHz was towed on the water surface both alongshore and on/off shore. The results show excellent bottom profiling to about the 25-ft depth that apparently conforms to general performance expectations of this system. Severe direct coupling between transmit and receive antennas masked responses from depths of 11 ft or less. Several diffraction hyperbolae distinctly originating from the bottom may have been caused by discontinues in the revetments. Unfortunately, no ground truth investigations were carried out by the survey party to ascertain the exact cause, and no maps showing the exact location of the survey are available. Several recommendations are made to improve the quality of data from future surveys. (AW)