Hybrid monitoring of location of a site confinee
US5892454A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1996 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Oct 21, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B21/245
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Method and apparatus for monitoring present location of a person ("confinee") who is to be confined to a designated site, which site can have a diameter as small as a few meters or as large as several kilometers. The present location of the confinee is checked at selected time intervals with time periods ranging from one second to thousands of seconds, as desired. The confinee wears a location-determining ("LD") unit that receives electromagnetic signals that contain information allowing determination of the present location of the LD unit, and thus of the confinee, from three or more non-collinear outdoor LD signal sources and from three or more non-collinear indoor LD signal sources. The indoor LD signal sources may be radiowave transmitters. The outdoor LD signal sources may be transmitters for a Loran, Omega, Decca, Tacan, JTIDS Relnav or PLRS or similar ground-based system, or transmitters for a satellite positioning system, such as GPS or GLONASS. The relative phases or transmission times for the signals from each indoor LD signal source are determined and provided for the LD unit. The present location or change location of the LD unit is determined and compared with the perm…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.