A method of determining a location of a mobile device in the presence of a spoofing signal includes obtaining current position information associated with the mobile device, determining a Global Navigation Satellite System (GNSS) signal search window for acquiring GNSS signals associated with a satellite based on the current position information, searching a GNSS signal associated with the satellite based on the GNSS signal search window, and determining updated position information of the mobile device based on at least information of the GNSS signal associated with the satellite.

A disciplined clock provides a disciplined time and a disciplined frequency synchronous with a reference clock. The disciplined clock includes: a time receiver to: receive a common view signal from the common view clock; and produce a receiver timing signal; a local clock to: receive a frequency correction; and produce a local timing signal; a time interval counter to: receive the receiver timing signal from the time receiver; receive the local timing signal from the lock clock; and determine a time difference between the receiver timing signal and the local timing signal; and a controller to: receive the time difference from the time interval counter; and communicate the frequency correction, based on the time difference, to the local clock.

A system and method for detecting spoofing of a Global Navigation Satellite System (GNSS) system using a plurality of antennas. Signals received by at least two of the plurality of antennas are authentication by use of one or more of a carrier phase authentication procedure, a signal power authentication procedure, and/or a channel distortion authentication procedure.

A pay television satellite broadcast includes validation data that can be used to validate authenticity of live global positioning system (GPS) data. The validation data may be included within entitlement messages and encrypted for security and selective reception by authorized receivers. A navigation system may compute checksums of received live GPS data and compare with the validation data for a match. A decision about whether or not to use the live GPS data may be taken based on whether or not the computed checksums match the validation data received via the pay television satellite broadcast signals.

The present invention sequentially and repeatedly accepts a plurality of types of information that can change with time, including position information obtained using a satellite signal, and correlates and records the accepted plurality of types of information with time information.

The present invention sequentially and repeatedly accepts a plurality of types of information that can change with time, including position information obtained using a satellite signal, and correlates and records the accepted plurality of types of information with time information.

Systems and methods for calculating single delta range differences using synthetic clock steering are provided. In certain embodiments, a system includes a first GNSS receiver that provides first delta range measurements and first measurement times associated with a plurality of GNSS satellites. The system further includes a second GNSS receiver that provides second delta range measurements and second measurement times associated with the plurality of GNSS satellites. Additionally, the system includes a processing unit that executes instructions that cause the processing unit to synchronize the second delta range measurements with the first delta range measurements to create synchronized delta range measurements. The executable instructions also cause the processing unit to calculate a single difference of the first delta range measurements and the synchronized delta range measurements for at least one satellite in the plurality of GNSS satellites.

The invention pertains to a method for operating a GNSS receiver in the presence of spoofed signals, the GNSS receiver having a plurality of satellite signal receive chains with a low associated antenna envelope correlation coefficient, the method comprising: receiving signals from said plurality of satellite signal receive chains; obtaining (1010) relative amplitude and phase values of respective signals as provided by a pair of satellite signal receive chains from among said plurality of satellite signal receive chains; clustering (1020) said received signals on the basis of said monitored relative amplitude and phase values; and asserting (1040) a spoofing detection state when said clustering reveals a cluster of signals exhibiting similar relative amplitude and phase values over a predetermined time frame (1030). The invention also pertains to a GNSS receiver.

A method for detecting a presence of interference during global navigation satellite system (GNSS)-based and inertial sensor signals (INS)-based localization of a vehicle includes determining localization results using a first filter configured to read in GNSS data and INS data, and storing a plurality of the determined localization results. The plurality of the determined localization results are after one another in terms of time and are each determined using the first filter. The method further includes analyzing the stored plurality of localization results using a second filter which differs from the first filter.

A method for detecting a presence of interference during global navigation satellite system (GNSS)-based and inertial sensor signals (INS)-based localization of a vehicle includes determining localization results using a first filter configured to read in GNSS data and INS data, and storing a plurality of the determined localization results. The plurality of the determined localization results are after one another in terms of time and are each determined using the first filter. The method further includes analyzing the stored plurality of localization results using a second filter which differs from the first filter.