Accession Number : AD0683568

Title :   TEMPORAL REFERENCE HOLOGRAPHY.

Descriptive Note : Research Communication no. 92,

Corporate Author : DOUGLAS AIRCRAFT CO INC HUNTINGTON BEACH CALIF ADVANCED RESEARCH LABS

Personal Author(s) : Metherell,A. F.

Report Date : FEB 1969

Pagination or Media Count : 20

Abstract : This paper describes a new form of acoustical and microwave holography which obviates the need for a real or electronically simulated reference wave. The use of linear (rather than square-law) detectors permits recording of the instantaneous non-time-averaged object wave potential within the acoustic or microwave cycle rather than the intensity of the sum of an object wave and a reference wave time-averaged over many cycles. The time at which the recording is made is the reference rather than a real or electronically simulated reference wave. To achieve the effect of a plane reference wave making an angle theta with the hologram plane, it is necessary to record the object wave potential instantaneously along a straight line on the hologram at the same time as the recording line is swept with velocity v across the plane in the direction perpendicular to the line. Then sin theta = a/v, where a is the speed of the acoustic or microwave radiation. The feasibility of this method is demonstrated by recording and reconstructing a 4.8 MHz temporal reference acoustical hologram made with a Sokolov ultrasonic camera system. (Author)

Descriptors :   (*SOUND, *PHOTOGRAPHY), (*STEREOPHOTOGRAPHY, MICROWAVE FREQUENCY), MICROWAVES, CAMERAS, CAMERA TUBES, CATHODE RAY TUBES, INTERFERENCE

Subject Categories : Holography
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE