Positioning system
First Claim
1. A method for a group of mobile objects to determine the absolute position of each member of the group, the method comprising:
- using an inertial navigation system to generate data indicative of the absolute positions of the objects;
receiving signals transmitted between the mobile objects and processing the signals to generate data indicative of the relative positions of the objections;
processing the relative position data to generate corrective data; and
correcting the absolute position data in accordance with the corrective data.
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Accused Products
Abstract
The invention provides a positional system intended to supplement positional information derived by means of a Global Positioning System (GPS), so as to provide positional data coverage in situations where the GPS data may be unreliable, for example due to local attenuation of satellite signals, in order to permit members of a group traversing difficult terrain to retain reasonably accurate information as to the whereabouts of the other group members should the GPS system fail. The positional system of the invention provides each group member with a readily transportable and relatively inexpensive inertial navigation system to generate approximate positional data and utilises radio location techniques to improve the accuracy of the approximate positional data.
48 Citations
19 Claims
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1. A method for a group of mobile objects to determine the absolute position of each member of the group, the method comprising:
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using an inertial navigation system to generate data indicative of the absolute positions of the objects;
receiving signals transmitted between the mobile objects and processing the signals to generate data indicative of the relative positions of the objections;
processing the relative position data to generate corrective data; and
correcting the absolute position data in accordance with the corrective data. - View Dependent Claims (2, 3, 4, 5)
determining the distances of the relative positions of the objects from the geometric mean; and
correcting the absolute position data in dependence upon the determined distances.
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4. A method according to claim 1, wherein time of flight measurements of the signals transmitted between the mobile objects are used to generate the relative position data.
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5. A method according to claim 4 wherein the signals are transmitted by radio equipment.
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6. An apparatus for use by a group of mobile objects to determine the position of each member of the group, the apparatus comprising:
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an inertial navigation system for generating data indicative of the absolute positions of the objects;
equipment for receiving signals transmitted between the mobile objects and processing the signals to generate data indicative of the relative positions of the objects; and
processing means for processing the relative position data to generate corrective data and correcting the absolute position data in accordance with the corrective data. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A system for a group of mobile objects to determine the absolute position of one or more members of the group, the system comprising:
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means for generating data that coarsely indicates the absolute positions of the objects of the group;
measuring means for measuring the relative positions of the objects of the group; and
processing means for refining the absolute position data in dependence upon the measured relative positions of the objects of the group to generate refined absolute position data indicating more accurately the absolute positions of one or more members of the group.
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Specification