Location fingerprinting

摘要

Methods, program products, and systems for using a location fingerprint database to determine a location of a mobile device are described. A mobile device can use a location fingerprint database to determine the location where GPS signals are unavailable. A server can generate location fingerprint data for the database. The server can generate the location fingerprint data using crowd sourcing, using known locations of signal sources, or both. The server can receive, from a sampling device, measurements of environment variables, e.g., signals from a signal source at one or more sampling points. The server can extrapolate, from the received measurements, estimated measurements at one or more locations in a venue. The server can store the extrapolated measurements as location fingerprint data. The server can send the location fingerprint data to a mobile device for determining a location of the mobile device when the mobile device is at the venue.

主权项

1. A method performed by one or more computers, the method comprising:
identifying one or more environment variables to be associated with a venue, each environment variable measuring a signal, the venue comprising a space accessible by a pedestrian and one or more constraints of movement of the pedestrian; determining a plurality of locations where the signal is detectable by a sensor of a mobile device when the mobile device is located at the venue, the locations being locations at the venue that are accessible by the mobile device and being different from a location of a signal source that produces the signal; determining location fingerprint data for the venue, the location fingerprint data comprising a fingerprint for each of the locations, the fingerprint including a set of one or more measurements that the mobile device is expected to receive when the mobile device measures the signal at the corresponding location, each measurement in the fingerprint corresponding to a different signal source, the location fingerprint data having a multi-dimensional data structure including an environment variable dimension and a location dimension, wherein: the environment variable dimension of the location fingerprint data corresponds to the one or more environment variables; the location dimension of the location fingerprint data corresponds to coordinates of the one or more locations; and one or more values in the location fingerprint data at a given location and given environment variable corresponds to a probability distribution that includes an expected value and a variance of the environment variable at the given location; and providing the location fingerprint data and an identifier of the venue to the mobile device for determining a location of the mobile device at the venue.