Remote Measurement of Water Currents Using Correlation Sonar.
Abstract
Acoustic backscatter measurement has certain advantages over other means of obtaining current velocity profiles in water. A complete profile can be obtained essentially instantaneously and platform motion is less restricted than with techniques requiring the use of mechanical probes. Doppler sonar is one approach, in use today, but it has some important limitations. These relate to the requirement for three receiving beams to measure the three components of velocity and the limitation on measurement accuracy when short duration signals are used to provide high resolution in depth. Correlation sonar is an alternate approach which has the capability of measuring the magnitude and direction of the mean velocity vector in a bounded resolution volume using a single transmitting/receiving array. Furthermore, measurement accuracy in a correlation system is enhanced rather than degraded by the use of wideband signals. This paper reviews the basic theory of correlation velocity measurement, and discusses system design constraints and operating parameters and their relationship to such performance measures as volume and depth resolution, profiling range, and measurement accuracy. In addition, results from a limited number of in-water measurements are presented. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1979
- Accession Number
- ADA080994
Entities
People
- J. A. Edward
Organizations
- General Electric