Abstract: Systems and methods compute an estimated altitude of a receiver using atmospheric data, including a pressure measured at a location of the receiver, a temperature measured by at a reference location, and a reference pressure corresponding to the reference location. The reference pressure is based on a pressure measured at the reference location, the temperature measured at the reference location, and an altitude corresponding to the reference location. The receiver receives the reference pressure from a transmitter. The estimated altitude may be used for determining the three-dimensional position of the receiver.

Abstract: Devices, systems, and methods for sending positional information from transmitters/beacons are disclosed. In one implementation a transmitter generates a range block including a ranging signal and a hybrid block including positioning data, and sends the range block and hybrid block in predefined slots in a transmit frame. A receiver in a user device receives signals from a plurality of transmitters and generates position/location information using trilateration and measured altitude information in comparison with transmitter altitude information.

Abstract: This disclosure relates to systems, methods, computer program products, and means that control access to position information at a receiver, or at another device external to the receiver, based on various considerations, including a requested service type, a user type, a device type, a software application type, a payment, and/or other characteristics associated with a particular software application or distributor of that software application. The disclosure further relates to systems, methods, computer program products and means for carrying out secure data transmissions intended for a particular application among other applications.

Abstract: Devices, systems, and methods for improving performance in positioning systems are disclosed. Signal processing methods are described for selecting certain spreading codes having desired auto and/or cross-correlation properties and generating, transmitting, and receiving signals generated using the selected codes.

Abstract: Embodiments describe determining position by selecting a set of digital pseudorandom sequences. The magnitudes of the cross-correlation between any two sequences of the chosen set are below a specified threshold. A subset of digital pseudorandom sequences are selected from the set such that the magnitudes of the autocorrelation function of each member of the subset, within a specified region adjacent to the peak of the autocorrelation function, are equal to or less than a prescribed value. Each transmitter transmits a positioning signal, and at least a portion of the positioning signal is modulated with at least one member of the subset. At least two transmitters of the plurality of transmitters modulate respective positioning signals with different members of the subset of digital pseudorandom sequences.

Abstract: Systems and methods are described for determining position of a receiver. The positioning system comprises a transmitter network including transmitters that broadcast positioning signals. The positioning system comprises a remote receiver that acquires and tracks the positioning signals and/or satellite signals. The satellite signals are signals of a satellite-based positioning system. A first mode of the remote receiver uses terminal-based positioning in which the remote receiver computes a position using the positioning signals and/or the satellite signals. The positioning system comprises a server coupled to the remote receiver. A second operating mode of the remote receiver comprises network-based positioning in which the server computes a position of the remote receiver from the positioning signals and/or satellite signals, where the remote receiver receives and transfers to the server the positioning signals and/or satellite signals.

Abstract: Systems and methods for estimating a height of a mobile device are described. A reference pressure estimate is generated using atmospheric data from one or more reference locations. Various approaches for determining the reference pressure estimate are described. The reference pressure estimate is used, along with a pressure measurement at a position of a mobile device, to estimate the height of the mobile device.

Abstract: Systems and methods are described for determining position of a receiver. The positioning system comprises a transmitter network including transmitters that broadcast positioning signals. The positioning system comprises a remote receiver that acquires and tracks the positioning signals and/or satellite signals. The satellite signals are signals of a satellite-based positioning system. A first mode of the remote receiver uses terminal-based positioning in which the remote receiver computes a position using the positioning signals and/or the satellite signals. The positioning system comprises a server coupled to the remote receiver. A second operating mode of the remote receiver comprises network-based positioning in which the server computes a position of the remote receiver from the positioning signals and/or satellite signals, where the remote receiver receives and transfers to the server the positioning signals and/or satellite signals.

Abstract: Devices, systems, and methods for improving performance in positioning systems are disclosed. Signal processing methods to determine a first time of arrival signal, along with associated hardware and software apparatus for implementing such methods are described.

Abstract: Described are systems and methods for time synching.

Abstract: Described are systems and methods for estimating a position of receiver using ranging signals from different regions in a network of transmitters. In some embodiments, each ranging signal that exceeds a quality criterion is assigned to one of several defined regions based on a characteristic of that ranging signal. A maximum number of ranging signals per region may be selected and used during trilateration.

Abstract: Described are systems and methods for estimating a position of receiver using co-located transmitters.

Abstract: Devices, systems, and methods for improving performance in positioning systems are disclosed. Signal processing methods to determine a first time of arrival signal, along with associated hardware and software apparatus for implementing such methods are described.

Abstract: Described are systems and methods for estimating a position of a receiver within a venue using localized networks of beacons. Certain aspects relate to different configurations of the networks. Other aspects relate to estimating the position of the receiver when the receiver approaches an edge of a localized network of beacon.

Abstract: Described are systems and methods for correcting range bias based on geometric system properties, and for correcting bias by using velocity estimates.

Abstract: Described are systems and methods for acquiring three-dimensional location information. Also described are systems and methods for using the acquired three-dimension location information to locate users and enhance their experience in relation to location-based services.

Abstract: Described are systems and methods for time synching to a network in an environment that contains obstructions disposed between a receiver component and a transmitting device of the network. In particular, an adaptive masking approach and an outage approach may be used to maintain time synchronization to the network. The adaptive masking approach may be used to track satellites above predefined elevation angles that correspond to the obstructions. The outage approach may be used to maintain time synchronization when the transmitting device of the network is not in view of the receiver component.

Abstract: Described are systems and methods for estimating error associated with one or more range measurements that are used to estimate the position of a receiver. Estimations of range error may be based on surveyed range errors for nearby position estimates. Estimations of range error may alternatively be based on comparisons of actual movement of a receiver to estimated movement between two position estimates.

Abstract: Described are systems and methods relating to localized networks of beacons.

Abstract: Described are systems and methods for identifying transmitters that adversely affect a trilateration result.