A method for localizing a mobile device having a processor, a memory, and sensor devices comprising a magnetometer sensor device, an accelerometer, and a sensor device for detecting and measuring a received signal strength, and capable of determining signal connectivity parameters, related to ambient wireless signals, the method comprising: monitoring, using the processor and the memory, mobile device magnetic data along a route being traversed by the mobile device in an indoor facility, the mobile device magnetic data being gathered by the magnetometer sensor device of the mobile device, wherein the mobile device magnetic data comprises magnetic field measurements including magnetic field strength and direction along the route; deriving, using the processor, from the mobile device magnetic data, a mobile device spatial derivative magnetic signature pattern representing a sequence of positions along the route, wherein the deriving comprises: calculating, for at least a pair of adjacent position states in the sequence of positions, an average magnetic field value, based on magnetic field measurements for the position states; computing, for the pair of adjacent position states in the sequence of positions, a difference between vertical components of magnetic field between the pair of adjacent position states; and determining the mobile device spatial derivative magnetic signature pattern, based on the difference between vertical components of magnetic field for the pair of adjacent position states and a distance between the pair of adjacent position states; accessing, using the processor, a repository of spatial derivative magnetic fingerprint data having associated respective positions along the route; matching, using the processor, the mobile device spatial derivative magnetic signature pattern with the spatial derivative magnetic fingerprint data of the repository to identify a correlating pattern in the repository; and using the processor, localizing the mobile device, based at least in part on matching, by identifying a position of the mobile device corresponding to the correlating pattern of the spatial derivative magnetic fingerprint data of the repository. monitoring, using the processor and the memory, mobile device magnetic data along a route being traversed by the mobile device in an indoor facility, the mobile device magnetic data being gathered by the magnetometer sensor device of the mobile device, wherein the mobile device magnetic data comprises magnetic field measurements including magnetic field strength and direction along the route; deriving, using the processor, from the mobile device magnetic data, a mobile device spatial derivative magnetic signature pattern representing a sequence of positions along the route, wherein the deriving comprises: calculating, for at least a pair of adjacent position states in the sequence of positions, an average magnetic field value, based on magnetic field measurements for the position states; computing, for the pair of adjacent position states in the sequence of positions, a difference between vertical components of magnetic field between the pair of adjacent position states; and determining the mobile device spatial derivative magnetic signature pattern, based on the difference between vertical components of magnetic field for the pair of adjacent position states and a distance between the pair of adjacent position states; calculating, for at least a pair of adjacent position states in the sequence of positions, an average magnetic field value, based on magnetic field measurements for the position states; computing, for the pair of adjacent position states in the sequence of positions, a difference between vertical components of magnetic field between the pair of adjacent position states; and determining the mobile device spatial derivative magnetic signature pattern, based on the difference between vertical components of magnetic field for the pair of adjacent position states and a distance between the pair of adjacent position states; accessing, using the processor, a repository of spatial derivative magnetic fingerprint data having associated respective positions along the route; matching, using the processor, the mobile device spatial derivative magnetic signature pattern with the spatial derivative magnetic fingerprint data of the repository to identify a correlating pattern in the repository; and using the processor, localizing the mobile device, based at least in part on matching, by identifying a position of the mobile device corresponding to the correlating pattern of the spatial derivative magnetic fingerprint data of the repository.