Methods and systems for determining vertical location in enclosed spaces

A hand-held computing device comprising:

• a processor;
• a memory coupled to the processor;
• a display device electrically coupled to the processor;
• a barometric pressure sensor electrically coupled to the processor;
• a wireless communication system electrically coupled to the processor, the wireless communication system configured to receive items of beacon data wirelessly from beacons external to the hand-held computing device;
• and
• wherein the memory stores a program that, when executed by the processor, causes the processor to:
• generate an estimate of expected vertical location based on the items of beacon data, wherein when the processor generates the estimate of expected vertical location, the program further causes the processor to:
• generate based on a set of probabilities calculated at least in part from map data and beacon data comprising beacon distances, beacon distance accuracies, and items of beacon data time information,
• generate an error covariance of the estimate of expected vertical location based on the items of beacon data,
• calculate a level normalized change based on measurements of barometric pressure by the barometric pressure sensor,
• calculate a vertical location of the hand-held computing device based on the level normalized change, the error covariance of the estimate of expected vertical location, and the estimate of expected vertical location, and
• display the vertical location on the display device.

A computer program product in a non-transitory computer-readable medium for location of a handheld computing device, the computer program product in a non-transitory computer-readable medium comprising instructions, which, when executed, cause a processor of a handheld computing device to perform:

• generating an estimate of expected vertical location based on items of beacon data received from beacons by a radio receiver of the hand-held computing device, wherein the generating the estimate of expected vertical location further comprises:
• generating based on a set of probabilities calculated at least in part from map data and beacon data comprising beacon distances, beacon distance accuracies, and items of beacon data time information;
• generating an error covariance of the estimate of expected vertical location based on the items of beacon data;
• calculating a level normalized change based on measurements of barometric pressure by a pressure sensor of the hand-held computing device;
• calculating a vertical location of the hand-held computing device based on the level normalized change, the error covariance of the estimate of expected vertical location, and the estimate of expected vertical location;
• and
• displaying the vertical location on a display device of the hand-held computing device.