Abstract: A method, system, and apparatus are disclosed for multipath isolation through the combined use of antenna diversity and frequency diversity. In particular, the present disclosure utilizes antenna diversity and frequency diversity to combat the deleterious effects of reflected signals on the positioning accuracy of satellite navigation systems. In at least one embodiment, the present disclosure uses two antennas and two frequencies for operation with a satellite navigation system. The present disclosure segregates the antennas and frequencies into two classes: references and monitors. The reference measurements are used for estimating the state of the vehicle, and the monitor measurements are used to detect faults that might degrade the reference estimation. Thus, the present disclosure enables an improvement in the positioning error experienced by roving users in downtown and indoor environments.

Abstract: Satellite-based navigation techniques can help determine a user's position on a map and can also determine directions to a destination. Functionality can be implemented to determine the user's orientation and direction of motion based on a captured image taken in the direction of motion. The captured image may be preprocessed to compensate for a camera angle and to vary image properties before being transmitted to a server. The user's orientation may be determined based, at least in part, on knowledge of a user's position on a map and comparing the captured image to a set of other images. Walking directions can accordingly be tailored based on the user's orientation.

Abstract: A system and methods for location authentication are presented. A subset of demodulated server received navigation signals are selected synchronized to client bit frames to provide synchronized server bit frames. A function of the synchronized server bit frames is computed to provide a server signature set. A client signature set and the server signature set are compared to provide a comparison result, and a location of a client device is authenticated based on the comparison result.

Abstract: Secure communication of information is effected from a first party to a second party when the first party knows its own global location and the global location of the second party, and employs what essentially is an undiscoverable code signal that is broadcast to, and received by, both the first and the second parties. The first party securely communicates information to the second party by modifying the code signal with the information that is to be communicated and sends the modified code signal to the second party. Illustratively, the code signal is related to the Y component of a GPS signal.

Abstract: Secure communication of information is effected from a first party to a second party when the first party knows its own global location and the global location of the second party, and employs what essentially is an undiscoverable code signal that is broadcast to, and received by, both the first and the second parties. The first party securely communicates information to the second party by modifying the code signal with the information that is to be communicated and sends the modified code signal to the second party. Illustratively, the code signal is related to the Y component of a GPS signal.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining that signalA contains the same unknown signal that is contained in signalB.

Abstract: A module for receiving a plurality of signals that are modulated with a common carrier, where each of the signals includes information that enables a determination of a distance from said receiver to a source that transmits the signal, and outputs to outside the module a digital representation of a downshifted replica of the received signals or, alternatively, outputs a stored and delayed version of the downshifted replica of the received signals together with information about the delay.

Abstract: An arrangement including a receiver that receives a plurality of signals from different source that are modulated with a common carrier, where each signal of the signals experiences a transit delay and Doppler frequency shift before reaching the receiver. The receiver includes means, such as a directional antenna, to ensure that the received signals are bona fide, or at least not subject to the same bogus signal or signals to which a second receiver may be subjected. The arrangement further includes means for processing a signal derived from the signals received by the receiver with signals provided by a supplicant module to reach a conclusion about the bona fide of the signals provided by the supplicant module.

Abstract: A module for receiving a plurality of signals that are modulated with a common carrier, where each of the signals includes information that enables a determination of a distance from said receiver to a source that transmits the signal, and outputs to outside the module a digital representation of a downshifted replica of the received signals or, alternatively, outputs a stored and delayed version of the downshifted replica of the received signals together with information about the delay.

Abstract: A receiver that receives a plurality of signals that are modulated with a common carrier, where each signal of said signals originates at a different source and experiences a transit delay and Doppler frequency shift before reaching the receiver, and where the transit delay and Doppler frequency shift are related to position and movement of each of the respective sources. The receiver includes means, such as a directional antenna, to ensure that the received signals are bona fide, or at least not subject to the same bogus signal or signals to which a second receiver may be subjected.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining that signalA contains the same unknown signal that is contained in signalB.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining, that signalA contains the same unknown signal that is contained in signalB.

Abstract: A receiver that receives a plurality of signals that are modulated with a common carrier, where each signal of said signals originates at a different source and experiences a transit delay and Doppler frequency shift before reaching the receiver, and where the transit delay and Doppler frequency shift are related to position and movement of each of the respective sources. The receiver includes means, such as a directional antenna, to ensure that the received signals are bona fide, or at least not subject to the same bogus signal or signals to which a second receiver may be subjected.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining that signalA contains the same unknown signal that is contained in signalB.

Abstract: A module for receiving a plurality of signals that are modulated with a common carrier, where each of the signals includes information that enables a determination of a distance from said receiver to a source that transmits the signal, and outputs to outside the module a digital representation of a downshifted replica of the received signals or, alternatively, outputs a stored and delayed version of the downshifted replica of the received signals together with information about the delay.

Abstract: Exemplary embodiments provide methods and systems of authenticating an integrated circuit (IC). The manufacturing location of an IC is authenticated by storing in the IC a local signature derived from a GPS signal that was received at the manufacturing location at the time of manufacture. A remote signature is derived from a GPS signal that was received at a remote site nearly simultaneously as the reception of the GPS signal at the manufacturing location. The local signature is compared to the remote signature at an authentication site to determine the authenticity of the IC.

Abstract: A positioning information distribution system for distributing positioning information through a data network is described. In one embodiment, the system distributes satellite information from a global positioning system (GPS). The system includes an information processing station connected to a data network accessible by wireless communication, a receiving station including a GPS receiver, and a mobile unit including a GPS receiver and a wireless receiver. The information processing station collects GPS satellite information from the receiving station and transmits the satellite information to the mobile unit using wireless communication. Alternately, a network of receiving stations are provided.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining, that signalA contains the same unknown signal that is contained in signalB.

Abstract: Authentication of a signal, signalA, that is provided as having been received from a source at a first global location by comparing it to a signal that is received from the source at a second global location, signalB, where signalB contains an unknown signal that is unique to the source, and determining that signalA contains the same unknown signal that is contained in signalB.

Abstract: A method and an apparatus using a low Earth orbiting (LEO) satellite signal to augment the Global Positioning System (GPS) for finding a location vector between a GPS user receiver and a GPS reference receiver. The GPS user receiver computes a LEO user-reference carrier phase difference and a GPS user-reference carrier phase difference for the LEO satellite signal and a GPS satellite signal, respectively, received simultaneously at the GPS user receiver and the GPS reference receiver. Carrier phase double differences are computed from a difference between the GPS user-reference carrier phases from two GPS satellites and either the LEO user-reference carrier phases from two LEO satellites or the GPS user-reference carrier phase from one GPS satellite and the LEO user-reference carrier phase from one LEO satellite. The location vector is computed from a difference between the double differences for two satellite geometries.