Scale Model Ultrasonic Study of Arctic Ice. Part 2.

• Main Authors: Himberger ,Douglas E, Mayer,Walter G
• Other Authors: GEORGETOWN UNIV WASHINGTON D C DEPT OF PHYSICS
• Format: Text
• Language: English
• Published: 1979
• Subjects: Snow; Ice and Permafrost; Acoustics; *UNDERWATER ACOUSTICS; *SEA ICE; COMPUTER PROGRAMS; THICKNESS; MECHANICAL PROPERTIES; SCALE MODELS; AIR; INTERFACES; LAYERS; THESES; ICE; ULTRASONICS; REFLECTIVITY; ACOUSTIC VELOCITY; SEA WATER; ACOUSTIC REFLECTION; SIMPLEX METHOD; ARCTIC OCEAN; ACOUSTIC BEAMS; UNDERICE; Angle of incidence; WUNR307352; Arctic; Arctic Ocean; Ice; permafrost; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA079401; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA079401

The work describes the mathematical background and the physical principles which were used to perform calculations of sonic reflectivity from the water side of a water-ice-air layered system where the angle of incidence is varied to produce changes of the magnitude and the phase of the incident sonic beam as it is reflected from the ice. It is shown that evaluation of these changes in reflectivity can be used to determine the thickness of the ice without having to be in direct mechanical contact with the ice. The computation of modulus and phase of the reflected beam is accomplished via a modified Simplex Computation Method. The basic concepts of the method are described, as are the modifications incorporated to make the program useful for calculations of ice thicknesses which one would ordinarily expect to encounter in the Artic Ocean. The report contains the description of a computer program to calculate the mode structure of an ice plate floating on water. Reflectivity of sonic signals which set up the modes is used to determine the thickness of the reflecting ice plate. See also Rept. no. GUUS-04799 dated 24 Apr 79, AD-A068 195. Master's thesis.