Patent ID: 9080874
Filing Date: 2015-07-14
Classification: G01C,G06F,G06K,G06T

Abstract:
1. An apparatus, comprising: at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to: acquire information indicating a measured magnetic field vector and information relating to an uncertainty measure of the measured magnetic field vector in at least one known location inside a building, wherein the indicated magnetic field vector represents magnitude and direction of the earth's magnetic field affected by the local structures of the building, and wherein the known location is defined in a frame of reference of a floor plan of the building, and the uncertainty measure represents at least one of uncertainty of the magnitude of the magnetic field vector and uncertainty of the direction of the magnetic field vector and indicates location-specific reliability of the measured magnetic field vector in the at least one known location; generate an indoor magnetic field map for at least part of the building on the basis of at least the acquired information and the floor plan, wherein the indoor magnetic field map comprises the magnetic field vector and the uncertainty measure of the magnetic field vector for the at least one location inside the building; and apply the uncertainty measure of the magnetic field vector comprised in the indoor magnetic field map for at least one of the following: location estimation of a person in the building (