Accession Number:

ADA214243

Title:

High Resolution Imaging by Phase Retrieval and Discrimination Using Speckle. Volume 1

Descriptive Note:

Final rept. Aug 1987-Jan 1989

Corporate Author:

ENVIRONMENTAL RESEARCH INST OF MICHIGAN ANN ARBOR

Report Date:

1989-03-01

Pagination or Media Count:

129.0

Abstract:

Concepts for unconventional sensors capable of high-resolution imaging and parameter estimation for the SDI midcourse discrimination application were developed. The basic sensor consists of a large filled array of small-aperture receivers that measure a laser-illuminated objects Fourier intensity in the aperture of the receiver. Reconstruction of a high-resolution image using a phase retrieval algorithm was investigated via theoretical analysis, computer simulations, and laboratory experiments. In particular, modification of the basic sensor to include a small-aperture, diffraction-limited imager within the array was studied. A method was developed to use the additional low resolution image data in the process of reconstructing a high resolution image. This method first retrieves the Fourier phase over the small aperture of the low resolution imager using the Gerchberg-Saxton algorithm and then proceeds with phase retrieval over the entire array aperture using the iterative Fourier transform algorithm. This method was successfully demonstrated via computer simulations. Reconstruction of the image of a simple two-part object from Fourier intensity data gathered in a laboratory experiment was also achieved. Non-imaging, speckle correlation methods were developed which use the data provided by the large array of receivers to measure rotation rates and separation rates for multiple objects. rrh

Subject Categories:

  • Lasers and Masers
  • Antimissile Defense Systems
  • Infrared Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE