Method and system for monitoring vehicles
First Claim
1. A system for determining positions of a vehicle equipped with a transponder which emits a first reply signal containing data identifying the vehicle in response to a first interrogation signal and which emits a second reply signal containing data specifying the altitude of the vehicle in response to a second interrogation signal, the system comprising:
- a squitter transmitter located on the vehicle for interrogating the transponder with the first and the second interrogation signals which are separated in time by a predetermined time spacing interval, in response to which first and second interrogation signals, the transponder transmits the first and second reply signals;
a plurality of spaced apart ground receive stations, each of which ground receive stations comprises means for;
(a) receiving and decoding data from the first and second reply signals,(b) determining a time of arrival of the first and second reply signals and the predetermined time spacing interval, and(c) determining an identity of the vehicle by combining data from the first reply signal with information derived from the predetermined time spacing interval;
a communications link connecting the ground receive stations with one of the ground receive stations; and
means, at the one of the ground receive stations, for receiving information from the other ground receive stations over the communication link, the information comprising the identity and time of arrival data determined from the time of arrival of the first and second reply signals, and for calculating from the time of arrival data the position of the vehicle.
2 Assignments
0 Petitions
Accused Products
Abstract
System for tracking a vehicle equipped with a transponder which emits a first reply signal containing data identifying the vehicle in response to a first interrogation signal and emits a second reply signal containing data specifying the altitude of the vehicle in response to a second interrogation signal, the system including: (a) a squitter transmitter located on the vehicle for interrogating the transponder with the first and the second interrogation signals which are separated in time by a predetermined time spacing interval, in response to which first and second interrogation signals, the transponder transmits the first and second reply signals; (b) a plurality of spaced apart ground receive stations, each of which includes a receiver and decoder for: (i) receiving and decoding data from the first and second reply signals, (ii) determining a time of arrival of the first and second reply signals and the predetermined time spacing interval, and (iii) determining an identity of the vehicle by combining data from the first reply signal with information derived from the predetermined time spacing interval; (c) a communications link for connecting the ground receive stations with one of the ground receive stations; and (d) a computer at the one of the ground receive stations for receiving information from the other ground receive stations over the communication link, the information including the identity and time of arrival data determined from the time of arrival of the first and second reply signals, and for calculating the position of the vehicle from the time of arrival data.
48 Citations
18 Claims
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1. A system for determining positions of a vehicle equipped with a transponder which emits a first reply signal containing data identifying the vehicle in response to a first interrogation signal and which emits a second reply signal containing data specifying the altitude of the vehicle in response to a second interrogation signal, the system comprising:
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a squitter transmitter located on the vehicle for interrogating the transponder with the first and the second interrogation signals which are separated in time by a predetermined time spacing interval, in response to which first and second interrogation signals, the transponder transmits the first and second reply signals; a plurality of spaced apart ground receive stations, each of which ground receive stations comprises means for; (a) receiving and decoding data from the first and second reply signals, (b) determining a time of arrival of the first and second reply signals and the predetermined time spacing interval, and (c) determining an identity of the vehicle by combining data from the first reply signal with information derived from the predetermined time spacing interval; a communications link connecting the ground receive stations with one of the ground receive stations; and means, at the one of the ground receive stations, for receiving information from the other ground receive stations over the communication link, the information comprising the identity and time of arrival data determined from the time of arrival of the first and second reply signals, and for calculating from the time of arrival data the position of the vehicle. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 16, 17, 18)
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11. A system for determining positions of a vehicle equipped with an IFF transponder and TACAN interrogation equipment comprising:
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a squitter transmitter located on the vehicle; enabling means, responsive to a TACAN interrogation pulse emitted by the TACAN interrogation equipment, for enabling the squitter transmitter at a predetermined time spacing interval after the enabling means responds to the TACAN interrogation pulse; the squitter transmitter providing, when enabled, an interrogation signal, in response to which interrogating signal, the IFF transponder transmits a reply signal containing data specifying the altitude of the vehicle; a plurality of spaced apart ground receive stations;
each of which ground receive stations comprises means for;(a) receiving the TACAN interrogation pulse and the IFF transponder reply signal and decoding first identification information from the TACAN interrogation pulse, (b) determining a time of arrival of the TACAN interrogation pulse and the IFF transponder reply signal and the predetermined time spacing interval; and
,(c) determining an identity of the vehicle by combining the first identification information with information derived from the predetermined time spacing interval; a communications link connecting the ground receive stations with one of the ground receive stations; and means, at the one of the ground receive stations, for receiving information from the other ground receive stations over the communication link, the information comprising the identity and time of arrival data determined from the time of arrival of the TACAN interrogation pulse and the IFF transponder reply signal, and for calculating from the time of arrival data the position of the vehicle. - View Dependent Claims (12, 13, 14, 15)
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Specification