US 2003/0156062 A1 · Position location and tracking method and system employing low frequency radio signal processing

Abstract

A position location system adapted for Military Operations in Urbanized Terrain (MOUT) training exercises that equips a player with a magnetic sensor for detecting a low frequency (LF) magnetic field from a plurality of stationary antennas. The distance between the player-borne sensor and a stationary antenna is proportional to the logarithm of the magnetic field intensity because the player remains within the “near field” of the stationary antenna. With scheduled transmissions from six stationary antennas, the position and angular orientation of a player bearing a three-axis magnetic field sensor may be resolved in three-dimensions to within one foot (30 cm). The LF magnetic field intensity is generally unaffected by structural obstructions or multipath distortion. The stationary antennas and transmitters may be permanently installed at little expense in any urban structure so that sensor-equipped emergency workers may be located and tracked within the structure during emergency fire and rescue operations.

Claims19

Dependent claims

A position locator system including one or more instrumented zones, the system comprising:

a plurality of antennas each having an orientation axis and a predetermined location on the periphery of at least one of the instrumented zones;
a transmitter coupled to each antenna for producing therein a signal current, whereby a magnetic signal is radiated therefrom;
and
one or more player units each having
a field sensor for producing a sensor signal representing the magnetic signals radiating from the antennas, and
a signal processor for generating player position data responsive to the sensor signal.

3 more elements

A method for reporting the position of a player unit in a position locator system including a controller and one or more instrumented zones each bounded by two antennas on two generally opposite sides, the method comprising the unordered steps of:

(a.1) radiating a first magnetic signal from the antenna on a first side of a first instrumented zone;
(a.2) receiving the first magnetic signal at the player unit;
(a.3) generating a first sensor signal representing the first magnetic signal received at the player unit;
(b.1) radiating a second magnetic signal from the antenna on a second side of the first instrumented zone generally opposite the first side thereof;
(b.2) receiving the second magnetic signal at the player unit;
(b.3) generating a second sensor signal representing the second magnetic signal received at the player unit;
(c.1) broadcasting a player position data signal corresponding to a combination of all of the sensor signals;
and
(c.2) receiving the player position data signal at the controller.

6 more elements

Dependencies are inferred from the claim text.

Position location and tracking method and system employing low frequency radio signal processing

Life of this patent

Position location and tracking method and system employing low frequency radio signal processing

Life of this patent

Abstract

Claims19