Safety alert and locating system
US4813025A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1987 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Jun 12, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/74
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for monitoring the safety and location of individuals includes a portable transceiver worn by each individual and a base control unit for sending interrogation signals to the individual units. The interrogation signals are transmitted through both air and water, and the individual units transmit a response through the medium through which the interrogation signal was received. The base unit measures both the elapsed time from transmission to reception and the incoming phase angles of the response signal, and converts these measurements to indications of distance and angle between the base unit and the individual transceivers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.