Apparatus and method for tracing a path travelled by an entity or object, and tag for use therewith
First Claim
1. A tracing system for providing a trace of a geographical path of travel previously taken by an entity or object, the system comprising:
- a tag device and a data retrieval unit;
the tag device being associated, in use, with the entity or object and comprising a radio receiver programmed to scan a predetermined radio band at different times as the entity or object traverses said path of travel, and to capture at a current location of the entity or object at each said time a frequency signature associated with said current location, said frequency signature representing the extant frequency spectrum expressed as signal strength versus frequency within said predetermined frequency band;
storage unit configured to store the frequency signature associated with each said current location for later retrieval; and
an output for outputting a resulting plurality of frequency signatures stored in said storage unit,the retrieval unit comprising a computer programmed to communicate with said output of the tag device, to retrieve a plurality of frequency signatures stored in said storage unit, to compare said frequency signatures with known antenna transmission data and geographical location data to determine the location of the tag device at the time when each stored frequency signature was captured, to derive the path of travel from the successive geographical locations, and to provide a trace of said path of travel.
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Accused Products
Abstract
Apparatus and method for tracing a geographical journey taken by an entity, for example an article (shipment), asset or person, on a worldwide map uses a miniature, passive, low power, radio receiver tag that is attached to the entity and collects multiple FM spectra during the travels of the entity. When the tag is retrieved at the end of the journey, the FM spectra are downloaded and compared against a collection of constructed spectra constructed from antenna transmission and location data derived. Correlating each of the spectra collected by the receiver tag with the corresponding spectra in the database allows the regions traversed by the receiver tag, and hence the entity, during its travels to be plotted.
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Citations
27 Claims
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1. A tracing system for providing a trace of a geographical path of travel previously taken by an entity or object, the system comprising:
- a tag device and a data retrieval unit;
the tag device being associated, in use, with the entity or object and comprising a radio receiver programmed to scan a predetermined radio band at different times as the entity or object traverses said path of travel, and to capture at a current location of the entity or object at each said time a frequency signature associated with said current location, said frequency signature representing the extant frequency spectrum expressed as signal strength versus frequency within said predetermined frequency band;
storage unit configured to store the frequency signature associated with each said current location for later retrieval; and
an output for outputting a resulting plurality of frequency signatures stored in said storage unit,the retrieval unit comprising a computer programmed to communicate with said output of the tag device, to retrieve a plurality of frequency signatures stored in said storage unit, to compare said frequency signatures with known antenna transmission data and geographical location data to determine the location of the tag device at the time when each stored frequency signature was captured, to derive the path of travel from the successive geographical locations, and to provide a trace of said path of travel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- a tag device and a data retrieval unit;
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15. A method of providing a trace of a geographical path previously taken by an entity or object comprising the steps of:
- associating with the entity or object having associated therewith a tag device having a radio receiver for capturing frequency spectra, a storage unit for storing captured spectra and output means for outputting a resulting plurality of captured frequency spectra, the method comprising the steps of;
scanning a predetermined radio frequency band with said radio receiver at each of a plurality of times as the entity or object traverses the path, and capturing at a current location of the entity or object at each of said times a frequency signature associated with said current location, said frequency signature representing the frequency spectrum extant expressed as signal strength versus frequency within said predetermined frequency band at each time, and storing a plurality of said captured frequency signatures in said storage unit for later retrieval; and when the tag device and entity/object have traversed the path, retrieving said plurality of captured frequency signatures from the tag device and correlating said captured frequency signatures with known antenna data and geographical location data to determine the location of the tag when each captured frequency signature was captured, deriving the path from the successive locations, and providing a trace of said travel path. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
- associating with the entity or object having associated therewith a tag device having a radio receiver for capturing frequency spectra, a storage unit for storing captured spectra and output means for outputting a resulting plurality of captured frequency spectra, the method comprising the steps of;
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27. A radio receiver tag device suitable for use in providing a trace of a path taken by an entity or object while accompanied by the radio receiver tag device, comprising:
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a radio receiver operable to scan a predetermined radio frequency band and capture data representing a frequency signature thereof, said frequency signature representing the extant frequency spectrum expressed as signal strength versus frequency within said predetermined frequency band; a storage unit configured to store a plurality of data records each corresponding to a respective one of a plurality of the frequency signatures; a controller for controlling the radio receiver to scan the radio frequency band at selected times, while the entity or object is traversing said path, and store the resulting plurality of frequency signatures in said storage unit for later retrieval; and an output device for outputting said plurality of frequency signatures.
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Specification