Andrew C Nicholas

US Patent:

20160377700, Dec 29, 2016

Filed:

Jun 23, 2016

Appl. No.:

15/190292

Inventors:

- Arlington VA, US
Andrew C. Nicholas - Glenelg MD, US

International Classification:

G01S 5/10

Abstract:

In a geolocation method and/or apparatus, a plurality of satellites is provided in a fixed Earth-Sun coordinate system or a fixed Earth-moon coordinate system. Two respective radio frequency band signals of the plurality of respective radio frequency band signals are received by at least one receiver from at least two satellites of the plurality of satellites, the at least one receiver comprising at least one respective geolocation. The at least one receiver generating at least two pluralities of equal Doppler shift contours corresponding to the at least two satellites of the plurality of satellites. The at least one receiver determines the at least one respective geolocation based at least in part on a universal time and intersections of the at least two pluralities of equal Doppler shift contours. The at least one receiver outputs the at least one respective geolocation.

US Patent:

20150100272, Apr 9, 2015

Filed:

Jul 25, 2014

Appl. No.:

14/341159

Inventors:

Andrew C. Nicholas - Glenelg MD, US
Nelson Creamer - Waldorf MD, US
Theodore T. Finne - Fairfax VA, US
Federico A. Herrero - Glenn Dale MD, US

Assignee:

The Government of the United States of America, as represented by the Secretary of the Navy - Washington DC

International Classification:

B64G 1/36
B64G 1/10

US Classification:

702154

Abstract:

A method and system is described for determining attitude for a satellite. A two-axis ram sensor head measures neutral winds and provides a density of the neutral winds. A three-axis magnetometer measures a geomagnetic field. A measurement interface module calculates attitude information, which includes three-axis attitude knowledge of a satellite relative to a local-vertical local-horizontal orbit frame, based on the combined ram measurements and magnetic field measurements, and provides the attitude information to a satellite that comprises the attitude sensor system.