A microprocessor-based one dimensional optical data processor for spatial frequency analysis

A high degree of accuracy was obtained in measuring the spatial frequency spectrum of known samples using an optical data processor based on a microprocessor, which reliably collected intensity versus angle data. Stray light control, system alignment, and angle measurement problems were addressed and solved. The capabilities of the instrument were extended by the addition of appropriate optics to allow the use of different wavelengths of laser radiation and by increasing the travel limits of the rotating arm to + or - 160 degrees. The acquisition, storage, and plotting of data by the computer permits the researcher a free hand in data manipulation such as subtracting background scattering from a diffraction pattern. Tests conducted to verify the operation of the processor using a 25 mm diameter pinhole, a 39.37 line pairs per mm series of multiple slits, and a microscope slide coated with 1.091 mm diameter polystyrene latex spheres are described

A general purpose wideband optical spatial frequency spectrum analyzer

The light scattered at various angles by a transparent media is studied. An example of these applications is the optical Fourier spectrum measurement resulting from various spatial frequencies which were recorded on a photographic emulsion. A method for obtaining these measurements consists of illuminating the test object with parallel monochromatic light. A stationary lens, placed in the resulting wavefield at a distance of one focal length from the object, will focus parallel waves emanating from the test object at a point lying in the focal plane of the lens. A light detector with a small filtering aperture is then used to measure the intensity variation of the light in the focal or transform plane of the lens. Such measurements require the use of a lens which is highly corrected for all of the common aberrations except chromatic aberration

Contract NAS 9-5829 (EASEP) Schedule II final report

The information presented herein is compiled and summarized primarily from data presented in monthly progress reports issued during the EASEP program. The period covered by this final report runs from 1 October 1968 through 15 June 1969.S/ A 65S to NAS 9-582

Review of The Quapaws

How to shake the hand of the unsmiling stranger in town and at the same time lose your shirt and all you own-such is the amazing and also tragic history of the American Indian. Although W. David Baird does not deviate much from the familiar and almost expected Jacksonian shakedown, he does offer succinct and at times moving accounts of how one formerly important tribe on the Mississippi-Arkansas trace was successively reduced in importance by its encounters with the French, the Spanish, and the Americans

A Comparison of Photointerpretive and Digital Production Methods for Four Key Remote Sensing-Based Information Products

No abstract availabl