Michael S Mcdonnell

US Patent:

49128531, Apr 3, 1990

Filed:

Nov 17, 1981

Appl. No.:

6/322308

Inventors:

Michael M. McDonnell - Woodbridge VA
Donald P. Dere - Lorton VA

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G01B 312

US Classification:

33228

Abstract:

A reticle plate provided with a reticle and three concentric circles of ving diameter and methods of use thereof, the invention allows a user to establish a north-oriented or south-oriented line by alignment of selected circumpolar stars with the circles. The circles are located on the reticle plate in positions determined by angles which exist between the celestial north (or south) pole and the particular low-magnitude circumpolar stars chosen as sighting points, the radii of the circles being directly proportional to the objective lens focal length of the theodolite or optical instrument within which the plate is used. A first method of the invention allows unambiguous location of the north or south pole by alignment of each of three selected stars with one each of the three circles. A second method provides data to a user sufficient to locate the pole by alignment of innermost and outermost circles respectively with one each of two of the selected stars.

US Patent:

45140596, Apr 30, 1985

Filed:

Sep 15, 1982

Appl. No.:

6/418318

Inventors:

Michael M. McDonnell - Woodbridge VA

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G06G 900
G02B 518

US Classification:

35016216

Abstract:

An apparatus for performing an incoherent optical Fourier transform inclu a source of incoherent light, means for generating and phase modulating a first zone plate, a second zone plate, means for detecting incoherent light processed by the apparatus, and means for filtering the output signal, thereby discriminating between the Fourier transform signal and background constant or bias signals. A method for performing incoherent optical Fourier transform is also disclosed.