THE MEASUREMENT AND INTERPRETATION OF PHASE FLUCTUATIONS IN THE OCEAN.
Abstract
The application of the phase lock loop as a phase shift demodulator to acoustic signals transmitted through the ocean is described. The output of the phase comparator in the loop is proportional to the phase difference between the input signal from the medium and the reference signal from the voltage controlled oscillator. This particular phase comparator has a sawtooth characteristic which is linear over a range of 360 degrees. The phase error can be expressed by a second-order, linear differential equation over the range - pi < Oe < pi and solutions obtained for different input conditions. Of particular interest is the phase error frequency response to input phase fluctuations. The laboratory task encompassed the design, construction, test and calibration of the loop plus development of a synchronizing system that switched between the crystal oscillator and the receiver when the input audio signal exceeds a threshold voltage. Experimental results from the application of the phase lock loop on a field program in the area of Key West, Florida are examined and explained by basic wave theory. This served as a check on the use of the phase lock loop as a phase shift detector. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 11, 1967
- Accession Number
- AD0652621
Entities
People
- R. A. Pezanowski
Organizations
- Pennsylvania State University