Hybrid monitoring of location of a site confinee
First Claim
1. A method for monitoring the location of a site confinee with reference to a permitted site that has at least one structure on the site, the method comprising the steps of:
- designating a site, having a curve of arbitrary shape as a site boundary and having at least one structure thereon, as a permitted site;
positioning a location determination (LD) unit on the body of a site confinee to determine the location of the LD unit from receipt of electromagnetic signals at the LD unit;
receiving outdoor LD signals at the LD unit from each of a first set of at least three outdoor LD signal sources, whose locations are known with high accuracy and are spaced apart from each other outside the structure, where each outdoor LD signal has an indicium that identifies the source of the signal;
receiving indoor LD signals at the LD unit from each of a first set of at least three outdoor LD signal sources, whose locations are known with high accuracy and are spaced apart from each other inside the structure, where each indoor LD signal has an indicium that identifies the source of the signal;
selecting a preferred set of LD signals from the first set of LD signals and the second set of LD signals, by applying at least one of a selected signal strength criterion and a selected signal quality criterion to the first set and to the second set of LD signals, and using the preferred set of LD signals to determine the location of the LD unit;
for each of a selected sequence of interrogation times, determining the present location of the LD unit, and determining whether the LD unit is within the permitted site at each such interrogation time; and
communicating at least one of (i) a selected alarm signal and (ii) information on a recent location of the LD unit, when at least one of a selected group of conditions is present, where the selected group of conditions includes at least one of (A) the condition that the present location of the LD unit is not within the permitted site for at least one of the interrogation times, and the confinee has not made arrangements beforehand to leave the permitted site and to travel in a region not within the permitted site and (B) the condition that the LD unit receives a selected location interrogation signal.
3 Assignments
0 Petitions
Accused Products
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 permitted site location coordinates at a sequence of selected times to determine if the confinee is present at the site at such times. The LD unit issues an alarm signal if the confinee is not on the site and has not arranged beforehand to leave the permitted site for a selected time interval. The permitted site can be redefined, for a selected time interval, to include the first permitted site, a second permitted site and a corridor extending between the first and second permitted sites for a selected time interval, after which the permitted site can be changed again to include only the first or the second permitted site or a portion thereof. This allows the confinee to temporarily leave the original permitted site to seek medical attention or to attend to other needs, or to be moved permanently to the second site.! The permitted site can be redefined at any time and for any subsequent time interval. One or more exclusion sites can be designated where the confinee is not permitted to go at any time.!
413 Citations
18 Claims
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1. A method for monitoring the location of a site confinee with reference to a permitted site that has at least one structure on the site, the method comprising the steps of:
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designating a site, having a curve of arbitrary shape as a site boundary and having at least one structure thereon, as a permitted site; positioning a location determination (LD) unit on the body of a site confinee to determine the location of the LD unit from receipt of electromagnetic signals at the LD unit; receiving outdoor LD signals at the LD unit from each of a first set of at least three outdoor LD signal sources, whose locations are known with high accuracy and are spaced apart from each other outside the structure, where each outdoor LD signal has an indicium that identifies the source of the signal; receiving indoor LD signals at the LD unit from each of a first set of at least three outdoor LD signal sources, whose locations are known with high accuracy and are spaced apart from each other inside the structure, where each indoor LD signal has an indicium that identifies the source of the signal; selecting a preferred set of LD signals from the first set of LD signals and the second set of LD signals, by applying at least one of a selected signal strength criterion and a selected signal quality criterion to the first set and to the second set of LD signals, and using the preferred set of LD signals to determine the location of the LD unit; for each of a selected sequence of interrogation times, determining the present location of the LD unit, and determining whether the LD unit is within the permitted site at each such interrogation time; and communicating at least one of (i) a selected alarm signal and (ii) information on a recent location of the LD unit, when at least one of a selected group of conditions is present, where the selected group of conditions includes at least one of (A) the condition that the present location of the LD unit is not within the permitted site for at least one of the interrogation times, and the confinee has not made arrangements beforehand to leave the permitted site and to travel in a region not within the permitted site and (B) the condition that the LD unit receives a selected location interrogation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification