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1. WO1997011882 - TECHNIQUES FOR OPTIMIZING AN AUTONOMOUS STAR TRACKER

Publication Number WO/1997/011882
Publication Date 03.04.1997
International Application No. PCT/US1996/015425
International Filing Date 26.09.1996
Chapter 2 Demand Filed 19.04.1997
IPC
B64G 1/36 2006.01
BPERFORMING OPERATIONS; TRANSPORTING
64AIRCRAFT; AVIATION; COSMONAUTICS
GCOSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
1Cosmonautic vehicles
22Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
24Guiding or controlling apparatus, e.g. for attitude control
36using sensors, e.g. sun-sensors, horizon sensors
G01C 21/02 2006.01
GPHYSICS
01MEASURING; TESTING
CMEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
21Navigation; Navigational instruments not provided for in groups G01C1/-G01C19/104
02by astronomical means
G05D 1/08 2006.01
GPHYSICS
05CONTROLLING; REGULATING
DSYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
1Control of position, course, altitude, or attitude of land, water, air, or space vehicles, e.g. automatic pilot
08Control of attitude, i.e. control of roll, pitch, or yaw
G06K 9/00 2006.01
GPHYSICS
06COMPUTING; CALCULATING OR COUNTING
KRECOGNITION OF DATA; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
9Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
G06K 9/64 2006.01
GPHYSICS
06COMPUTING; CALCULATING OR COUNTING
KRECOGNITION OF DATA; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
9Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
62Methods or arrangements for recognition using electronic means
64using simultaneous comparisons or correlations of the image signals with a plurality of references, e.g. resistor matrix
CPC
B64G 1/244
BPERFORMING OPERATIONS; TRANSPORTING
64AIRCRAFT; AVIATION; COSMONAUTICS
GCOSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
1Cosmonautic vehicles
22Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
24Guiding or controlling apparatus, e.g. for attitude control
244Attitude control
B64G 1/36
BPERFORMING OPERATIONS; TRANSPORTING
64AIRCRAFT; AVIATION; COSMONAUTICS
GCOSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
1Cosmonautic vehicles
22Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
24Guiding or controlling apparatus, e.g. for attitude control
36using sensors, e.g. sun-sensors, horizon sensors
B64G 1/361
BPERFORMING OPERATIONS; TRANSPORTING
64AIRCRAFT; AVIATION; COSMONAUTICS
GCOSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
1Cosmonautic vehicles
22Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
24Guiding or controlling apparatus, e.g. for attitude control
36using sensors, e.g. sun-sensors, horizon sensors
361using star sensors
G01C 21/025
GPHYSICS
01MEASURING; TESTING
CMEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
21Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
02by astronomical means
025with the use of startrackers
G06K 9/00
GPHYSICS
06COMPUTING; CALCULATING; COUNTING
KRECOGNITION OF DATA; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
9Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
G06K 9/6211
GPHYSICS
06COMPUTING; CALCULATING; COUNTING
KRECOGNITION OF DATA; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
9Methods or arrangements for reading or recognising printed or written characters or for recognising patterns, e.g. fingerprints
62Methods or arrangements for recognition using electronic means
6201Matching; Proximity measures
6202Comparing pixel values or logical combinations thereof, or feature values having positional relevance, e.g. template matching
6203Shifting or otherwise transforming the patterns to accommodate for positional errors
6211Matching configurations of points or features, e.g. constellation matching
Applicants
  • LOCKHEED MARTIN CORPORATION [US]/[US]
Inventors
  • VAN BEZOOIJEN, Roelof, W., H.
Agents
  • RADLO, Edward, J.
Priority Data
08/534,37828.09.1995US
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) TECHNIQUES FOR OPTIMIZING AN AUTONOMOUS STAR TRACKER
(FR) TECHNIQUES D'OPTIMISATION D'UN SUIVEUR STELLAIRE AUTONOME
Abstract
(EN)
A method for determining the attitude of a spacecraft (1) by observing stars (2) within a starfield (3). A detector (13), camera electronics (14), and computer (15) located on board the spacecraft (1) are used to generate a set of star match groups by matching pairs of stars observed by the detector (13) with pairs of guide stars from a stored database (18) of guide stars. Match groups having small numbers of stars are eliminated. Non-eliminated match groups are validated. Redundant match groups are eliminated. A match group having the largest number of stars is selected. Finally, the attitude of the spacecraft (1) is derived from positions of guide stars within the selected match group. The guide star database (18) can be broken into an acquisition guide star database (8) and a supplementary guide star database (9). The field of view (20) of detector (13) can be broken into a grid of pixels overlaid by a grid of superpixels (21). The guide star pairs are preferably presorted in order of increasing angular separation. An identification matrix (IDGRP) can be used to speed the star identification process.
(FR)
La présente invention concerne un procédé de détermination de l'orientation d'un engin spatial (1) par l'observation des étoiles (2) d'un champ d'étoiles (3). Un détecteur (13), une caméra électronique (14) et un calculateur (15) embarqués dans l'engin spatial (1) servent à générer un ensemble de groupes de concordances d'étoiles en faisant correspondre à des paires d'étoiles connues d'une base de données (18) d'étoiles repères des paires d'étoiles observées par le détecteur (13). Les groupes de concordances constitués d'étoiles en petit nombre sont éliminés. Les groupes de concordances non éliminés sont sélectionnés. Les groupes de concordances redondants sont éliminés. Finalement, l'orientation de l'engin spatial (1) est déduite des positions des étoiles repères du groupe de concordances sélectionné. La base de données (18) d'étoiles repères peut être décomposée en une base de données (8) d'acquisition d'étoiles repères, et en une base de données (9) de complément d'étoiles repères. Le champ (20) du détecteur (13) peut se décomposer en une matrice de pixels que vient recouvrir une matrice de superpixels (21). Les paires d'étoiles repères sont de préférence préalablement triées selon l'ordre croissant de leur séparation angulaire. Pour accélérer le processus d'identification des étoiles, il est possible d'employer une matrice d'identification (IDGRP).
Also published as
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