Location of emergency service workers
US5552772A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1993 |
| Grant date | Sep 3, 1996 |
| Priority date | — |
| Expiry date | Dec 20, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B21/0294
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Method and apparatus for monitoring the present location of an emergency or general serviceperson, such as a firefighter or a hazardous materials spill clean-up specialist, assigned to perform emergency services at a designated site. The site diameter can be as small as a few meters or as large as several kilometers. The serviceperson's present location can be checked at selected time intervals with time periods ranging from a few hundred milliseconds to thousands of seconds, as desired. The serviceperson wears or carries 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 serviceperson, from three or more signal sources. These signal sources may be FM subcarrier signal transmitters, or may be an integrated combination of FM subcarrier signal transmitters and (1) transmitters for a Loran, Omega, Decca, Tacan, JTIDS Relnav or PLRS or other ground-based system, or (2) transmitters for a satellite-based positioning system, such as GPS or GLONASS, or other broadcast sources. The relative phases or transmission times for the signals from each source are determined…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.