Multi-lateration system with automatic calibration and error removal
US6380894B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2000 |
| Grant date | Apr 30, 2002 |
| Priority date | — |
| Expiry date | Aug 29, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/825
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration transmissions from object-attached tags, to geolocate objects within a monitored environment. An object location processor is coupled to distributed tag transmission readers over signal transport paths having different transport delays, and carries out time-of-arrival differentiation of first-to-arrive transmissions from a tag to determine where its object is located. Geolocation errors associated with variations in parameters of the signal transport paths are effectively removed by installing one or more ‘reference’ tags, whose geolocations are precisely known. Using a background calibration routine that is exercised at a relatively low cycle rate, emissions from the reference tags are processed and coupled to the geolocation processor. The calculated geolocations of the reference tags are compared with their actual locations. Any offset between the two geolocation values is used to adjust time delay offsets associated with signal transport paths between the readers and the geolocation processor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.