Generating and using a location fingerprinting map

1. A computerized method for building a multisensory location map, the method comprising:

receiving, by an interface, multiple multisensory data vectors acquired by multiple mobile devices at multiple locations and accelerometer readings obtained upon movement of at least one device carried by at least one user between the multiple locations; at least a portion of said movement being walking; at least a majority of the multiple locations are located within an area in which an accuracy of global positioning system (GPS) based navigation is below an allowable threshold;

extracting, out of accelerometer readings, for at least one step of said walking, accelerometer information related to multiple walking phases of said at least one step; for at least two of said multiple walking phases of said at least one step, by means of said accelerometer information, real-time correcting a currently measured Z vector, and a pitch angle and a roll angle thereof, thereby compensating for horizontal accelerations;

processing the accelerometer information related to said at least two of said multiple walking phases to determine a direction of propagation of the at least one user;

estimating, from said direction of propagation, at least one location of said at least one user; and

calculating, in response to the multiple multisensory data vectors and said at least one estimated location, a location fingerprinting map that comprises multiple grid points; each of the multiple grid points comprising a multisensory grid point fingerprint and grid point location information derivable from said at least one estimated location

further wherein said direction of propagation of said user is derivable directly from said accelerometer information without need for double integration of said accelerometer signal.

2. The computerized method according to claim 1 , further comprising: processing location information indicative of paths of multiple users within the indoor area to provide path information indicative of paths of the multiple users; and processing the path information to generate an estimated three dimensional map of the indoor area.

3. The computerized method according to claim 1 , wherein at least one of the multiple multisensory data vectors comprises at least one of: ambient noise, temperature, and earth magnetic field information.

4. The computerized method according to claim 1 , wherein at least one of the multiple multisensory data vectors comprises pedometer information.

5. The computerized method according to claim 1 , additionally comprising steps of: obtaining, from said corrected currently measured Z vector, a Z vector pointing toward Earth's center; calculating, from said Z vector pointing toward earth's center, a surface parallel to Earth's face (perpendicular to said Z vector pointing toward earth's center); estimating, from said surface parallel to Earth's face and from a magnetic north measured by at least one built-in magnetometer in said at least one device, an offset selected from a group consisting of: an azimuth offset from magnetic north and a heading offset from geometric north; and correcting said direction of propagation based on said offset.