Radio ranging, navigation, and location system with correction for systematic errors
First Claim
1. A radio ranging and navigation system comprising a plurality of stations at known geographical locations, an unlimited number of mobile receiver stations at independent locations, means in each of said known stations for enabing it to operate in a reference mode or a wing repeating mode, means for systematically shifting the modes of operation throughout said known stations, means responsive to a detection of signals sent after each of said shifting of said modes for detecting apparent distances between stations, means responsive to variations in said apparent distances for calculating systematic errors, and means responsive to said systematic errors for correcting said apparent distances to become true differential time measurements.
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Accused Products
Abstract
A radio ranging system has at least one receiver which receives pulses over a direct path and over a longer delayed path from each of two or more fixed repeater stations. From the reception times of pulses which have traveled over these paths at different travel times from the fixed stations, a computer calculates the hyperbolic distances separating the passive receiver and the several fixed reference stations. By interchanging the roles of the various fixed stations, the computer compares the results of timing calculations of the same distances based on the different sets of data. From this comparison, the systematic timing errors of the system can be isolated and added or subtracted from the time measuring results, leaving differential time measurements without systematic error.
55 Citations
18 Claims
- 1. A radio ranging and navigation system comprising a plurality of stations at known geographical locations, an unlimited number of mobile receiver stations at independent locations, means in each of said known stations for enabing it to operate in a reference mode or a wing repeating mode, means for systematically shifting the modes of operation throughout said known stations, means responsive to a detection of signals sent after each of said shifting of said modes for detecting apparent distances between stations, means responsive to variations in said apparent distances for calculating systematic errors, and means responsive to said systematic errors for correcting said apparent distances to become true differential time measurements.
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6. A process of using radio ranging and navigation systems comprising the steps of:
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(a) locating at least three known stations in a geographical pattern; (b) transmitting signals from a first of said known stations (called a reference station) to the other of said two known stations; (c) repeating the transmitted pulses at said other two known stations (called wing repeating stations); (d) detecting a time period at a fourth station (called the mobile receiver) beginning with the receipt of the pulse transmitted in step (b) and ending with the receipt of a pulse repeated in step (c); (e) shifting the roles of said known stations so that the second of said known stations is operating in the reference mode and the remaining ones of said known stations are operating in the wing repeating mode and repeat step (d); (f) shifting the roles of said known stations so that each of said known stations has a turn in the reference mode while the remaining ones of said known stations are operating in the wing repeating mode and repeat step (d); and (g) adding the time periods of reciprocal pairs of said known stations when operating in the reference mode and in the wing repeater mode detected during steps (e) and (f) and comparing to the known distance between the pairs of known stations in order to find systematic errors in operations. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13)
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- 14. A radio ranging and navigation system comprising a plurality of fixed stations at known geographical locations, at least one station at an unknown location, each of said fixed stations being able to operate in a reference mode, and a wing mode, means for systematically shifting the modes of operation throughout said system so that the fixed stations take turns operating in the reference mode, means responsive to a detection of signals sent during said shifting modes for detecting apparent measurements between stations, means responsive to variations in said apparent measurements for calculating systematic errors, and means responsive to said systematic errors for correcting said apparent measurements to become true measurements.
Specification