Location system and method
AssigneeRf Visibility LLC
InventorsEdwin T. Horton, James N. Rothbarth
Life of this patent
Estimating the term…
Abstract
An autonomous system of at least four transceivers located at fixed positions on a campus are networked to each other. Persons on the campus carries a fob or other transmitter. Each transceiver has a clock synchronized in time by a GPS satellite time signal. A location processor knows the fixed locations of the transceivers. When activated, each fob (of unknown location) transmits a unique alert signal. Each transceiver receives the alert signal. Based on time of receipt and known information, the location processor calculates a distance relative to each transceiver at which the fob is located to determine the location of the fob.
Claims33
A location system for use with a satellite transmitting a time information signal comprising:
- A plurality of transmitters, each transmitter when activated transmitting an alert signal, each said transmitter initially within an area at an unknown location;
- At least four transceivers connected by a network and positioned within or adjacent the area, each said transceiver in communication with the transmitters, each said transceiver having a fixed, known position in space, each said transceiver having a local clock, each said transceiver configured for receiving the alert signal and configured for receiving the time information signal used to synchronize its local clock, each said transceiver determining a time of receipt of the alert signal based on the local clock of the transceiver synchronized to the time information signal;
- and
- A processor on the network for determining the location of each of the transmitters within the area, said processor configured for receiving via the network the time of receipt of the alert signal by each transceiver, said processor configured to calculate the location of the transmitters within the area based on the received time of receipt of the alert signal by each transceiver and based on the fixed, known position of each transceiver.
In a location system for use with:
- A plurality of transmitters, each transmitter when activated transmitting an alert signal, each said transmitter initially within an area at an unknown location;
- At least four transceivers connected by a network and positioned within or adjacent the area, each said transceiver in communication with the transmitters, each said transceiver having a fixed, known position in space, each said transceiver determining a position of a activated transmitter relative to each said transceiver, the improvement comprising:
- each transmitter comprising a flat card-like housing having buttons on both sides of the card which when simultaneously activated cause the transmitter to transmit an alert signal.
Dependencies are inferred from the claim text.