Space-time calibration system and method
AssigneeDigimarc Corporation
InventorGeoffrey Rhoads
Life of this patent
Estimating the term…
Abstract
A space-time calibration system and method implement space-time solutions, in which, in one preferred embodiment, a single node determines its own space-time solutions based on other network nodes with which the single node communicates. In other preferred embodiments, space-time solutions for the node can be generated using other resources in the network. The disclosed system and method enable reliable, precise object positioning particularly for environments where the Global Positioning System (GPS) is blocked or subject to interference such as within the urban core.
Claims24
A space-time calibration method of determining position and timing information relating to one or more nodes of multiple nodes occupying locations in a spatial region and communicating with one another, comprising:
- associating in a spatial region multiple nodes including a transmitting node and receiving nodes, the transmitting node producing a plurality of ping transmit events to the receiving nodes and the receiving nodes producing ping receive events by receiving and associating receive count stamps to the plurality of ping transmit events, the receive count stamps based on independent clocks operating in the receiving nodes, the independent clocks characterized by clock rate differences between the independent clocks;
- developing pung signals, the pung signals each including a record of ping events comprising a plurality of the ping transmit events and the ping receive events during a data recording time interval, the pung signal for each receiving node including the receive count stamps corresponding to the plurality of ping receive events produced during the data recording time interval;
- and
- receiving plural pung signals from a plurality of the receiving nodes, the plural pung signals comprising receive count stamps based on independent clocks in the receiving nodes, and processing the plural pung signals to determine, for each one of a number of nodes of the multiple nodes, location information corresponding to a geographic location occupied by the node in the spatial region, the location information determined for one of the number of nodes being a function of the pung signals received from the at least one other of the number of receiving nodes.
A space-time calibration engine, comprising:
- an input configured to receive count-stamped information signals propagating through a medium and received by an antenna from multiple nodes occupying a spatial region, the multiple nodes including source and receiving nodes operating with independent clocks characterized by clock rate differences between the independent clocks, and the count-stamped information signals carrying information relating to transmit and receive events of the source and receiving nodes based on count stamps obtained from the independent clocks of plural receiving nodes;
- and
- a processor determining from information carried by the count-stamped information signals, for each one of a number of the multiple nodes, location information corresponding to a geographic location occupied by the node in the spatial region and the clock rate difference of the clock operating in the node, the geographic location determined for one of the number of the multiple nodes being a function of each of the receive events of at least one other of the number of the multiple nodes;
- wherein the processor determines the location information from a pung signal, the pung signal representing a record of ping events comprising a plurality of the transmit events and a plurality of the receive events during a data recording time interval, the pung signal for each receiving node including receive count stamps corresponding to the plurality of receive events produced during the data recording time interval.
Dependencies are inferred from the claim text.