Accession Number : ADA299171

Title :   Microwave Probe for Mass Measurements of a Water Plume.

Descriptive Note : Final rept.,

Corporate Author : NAVAL SURFACE WARFARE CENTER DAHLGREN DIV SILVER SPRING MD

Personal Author(s) : Choe, J. Y. ; Boulais, K. A. ; Chun, S. T. ; Irwin, K. A.

PDF Url : ADA299171

Report Date : 30 SEP 1995

Pagination or Media Count : 22

Abstract : The use of water plumes produced by shallow underwater explosions is being studied as an effective, low cost defense of ships against low flying missiles. The key element for the success of this concept is the total water mass contained within the plume. An experimental program has been conducted to measure the plume water mass in situ since no previous data exist relative to this ship self defense concept. Here we describe a microwave probe that was used to measure the amount of water in the plume. The method is based on the attenuation characteristics of a microwave beam that has been propagated through the plume. The attenuation coefficient can be obtained by measuring the amplitude of the wave after traversing the plume. This information can then be used to derive the water density since the attenuation characteristics depend only on the macroscopic volume ratio of water to air. In this paper, we first formalize the theory relating the water density to the microwave attenuation rate. After the experimental implementation of the theory has been laid out, specific experimental results from the actual field tests are presented.

Descriptors :   *MEASUREMENT, *WATER, *MICROWAVE EQUIPMENT, *PLUMES, DENSITY, PROBES, VOLUME, ANTIMISSILE DEFENSE SYSTEMS, LOW COSTS, MASS, FIELD TESTS, EXPLOSION EFFECTS, RADIATION ATTENUATION, SHIP DEFENSE SYSTEMS, UNDERWATER EXPLOSIONS, SHALLOW DEPTH, MICROWAVE BEAMS.

Subject Categories : Magnetic & Electric Fld Detection & Detectors
      Explosions

Distribution Statement : APPROVED FOR PUBLIC RELEASE