Systems and methods for calibration based indoor geolocation

A method of determining a location of a user within an indoor environment, the method comprising:

• receiving at a first time instant, a first set of radio frequency (RF) data from a plurality of RF sources;
• computing, based at least in part on the first set of RF data, a first location estimate and a second location estimate;
• receiving at a second time instant:
• (i) a second set of RF data from the plurality of RF sources, and (ii) tracking data from an inertial navigation system;
• computing, based at least in part on the second set of RF data, a third location estimate and a fourth location estimate;
• computing at the second time instant:
• (i) a fifth location estimate based in part on the first location estimate, and (ii) a sixth location estimate based in part on the second location estimate, both the fifth and sixth location estimates also being based in part on the tracking data;
• computing an error metric by comparing:
• (i) the fifth location estimate with at least one of the third and fourth location estimates, and (ii) the sixth location estimate with at least one of the third and fourth location estimates;
• and
• designating based at least in part on the error metric:
• (i) one of the first and second location estimates as a location of the user at the first time instant, and (ii) one of the third and fourth location estimates as a location of the user at the second time instant.

A method of calibrating a map-point grid for indoor location determination, the grid comprising a plurality of map points, each having a radio frequency (RF) data fingerprint being associated therewith, the method comprising:

• receiving:
• (i) RF signal data from a plurality of RF sources and (ii) tracking data from a sensor, the tracking data indicating at least one of a user's orientation relative to a map point and a user's movement relative to a base map point;
• and
• updating the map-point grid by at least one of adding a new map point to the grid and updating an existing map point of the grid, based on, at least in part, at least one of:
• (i) adjusted RF data obtained by adjusting the received RF data using the tracking data, and (ii) a combination comprising the received RF data and a location based on a user specified location indication and the tracking data.

A method of calibrating a map-point grid for indoor location determination, the grid comprising a plurality of map points, each having a radio frequency (RF) data fingerprint being associated therewith, the method comprising:

• receiving RF signal data from a plurality of RF sources;
• selecting a map;
• selecting a set of other map points from the map-point grid, each of which is within a threshold distance from the selected map point;
• computing a fingerprint as a function of the received RF signal data and the RF signal data associated with each of the other map points in the set;
• associating the computed fingerprint with the selected map point;
• updating the map-point grid using the selected map point and the fingerprint associated therewith.

A system for determining a location of a user within an indoor environment, the system comprising:

• a receiver adapted to receive (i) radio frequency (RF) signal data from each RF source of a plurality of RF sources, and (ii) tracking data from a sensor;
• and
• a processor adapted to:
• (i) compute a yield of the RF source based on the received data, by computing a frequency of the received RF data over at least one of a period of time or a number of observations, (ii) select a subset of fingerprints from a database of fingerprints, based on, at least in part, the yield associated with each of the plurality of RF sources, and (iii) determine a location of a user based on, at least in part:
• (a) the RF signal data received from each of the RF sources in the subset, and (b) the received tracking data.

A system for determining a location of a user within an indoor environment, the system comprising:

• a receiver adapted to:
• (i) receive at a first time instant, a first set of radio frequency (RF) data from a plurality of RF sources, (ii) receive at a second time instant:
• (a) a second set of RF data from the plurality of RF sources, and (b) tracking data from an inertial navigation system;
• and
• a processor adapted to compute:
• compute based at least in part on the first set of RF data, a first location estimate and a second location estimate;
• compute based at least in part on the second set of RF data, a third location estimate and a fourth location estimate;
• compute a fifth location estimate based in part on the first location estimate, and a sixth location estimate based in part on the second location estimate, both the fifth and sixth location estimates also being based in part on the tracking data;
• compute an error metric by comparing:
• (i) the fifth location estimate with at least one of the third and fourth location estimates, and (ii) the sixth location estimate with at least one of the third and fourth location estimates;
• and
• designate based at least in part on the error metric:
• (i) one of the first and second location estimates as a location of the user at the first time instant, and (ii) one of the third and fourth location estimates as a location of the user at the second time instant.

A system for calibrating a map-point grid for indoor location determination, the grid comprising a plurality of map points, each having a radio frequency (RF) data fingerprint being associated therewith, the system comprising:

• a receiver adapted to receive:
• (i) RF signal data from a plurality of RF sources and (ii) tracking data from a sensor, the tracking data indicating at least one of a user's orientation relative to a map point and a user's movement relative to a base map point;
• and
• a processor adapted to update the map-point grid by at least one of adding a new map point to the grid and updating an existing map point of the grid, based on, at least in part, at least one of:
• (i) adjusted RF data obtained by adjusting the received RF data by the processor using the tracking data, and (ii) a combination comprising the received RF data and a location based on a user specified location indication and the tracking data.

An article of manufacture, comprising a non-transitory machine-readable medium storing instructions that, when executed by a machine configure the machine, for calibrating a map-point grid for indoor location determination, the grid comprising a plurality of map points, each having a radio frequency (RF) data fingerprint being associated therewith, to:

• receive:
• (i) RF signal data from a plurality of RF sources and (ii) tracking data from a sensor, the tracking data indicating at least one of a user's orientation relative to a map point and a user's movement relative to a base map point;
• and
• update the map-point grid by at least one of adding a new map point to the grid and updating an existing map point of the grid, based on, at least in part, at least one of:
• (i) adjusted RF data obtained by adjusting the received RF data using the tracking data, and (ii) a combination comprising the received RF data and a location based on a user specified location indication and the tracking data.

A system for calibrating a map-point grid for indoor location determination, the grid comprising a plurality of map points, each having a radio frequency (RF) data fingerprint being associated therewith, the system comprising:

• a receiver adapted to receive RF signal data from a plurality of RF sources;
• and
• a processor adapted to:
• select a map point;
• select a set of other map points from the map-point grid, each of which is within a threshold distance from the selected map point;
• compute a fingerprint as a function of the received RF signal data and the RF signal data associated with each of the other map points in the set;
• associate the computed fingerprint with the selected map point;
• and
• update the map-point grid using the selected map point and the fingerprint associated therewith.

A method of calibrating a map-point grid for indoor location determination, the grid comprising a plurality of map points, each having a radio frequency (RF) data fingerprint being associated therewith, the method comprising:

• receiving RF signal data from a plurality of RF sources and a user specified location indication;
• associating the received RF data and a location corresponding to the received location indication with a map point;
• and
• updating the map-point grid using the map point.