| 摘要 |
<p>A system determines the position of a person or other body accompanied by a radio signal transmitter which constantly generates a radio signal of a predetermined frequency or is adapted to generate such a radio signal when the user manually operates the transmitter should an emergency arise. The system includes two different antenna networks, one comprising a plurality of non-directional antennas disposed substantially evenly over a specific area, always ready to receive the radio signal which will or may be transmitted from anywhere in the area, and the other comprising directional antennas mounted at several points in the area. In response to the radio signal being monitored by one or more of non-directional antennas, at least two of directional antennas come into operation and two different directions in which the respective directional antennas show the maximum field strength are detected with field strength meters attached thereto, which makes it possible to determine an exact position of the signal source by triangular surveying. A computer may be a help to operation of the system.</p> |
