Embodiments including a method and apparatus for correction of a global navigation satellite system (GNSS) are described. In one example, the apparatus includes a communication interface and a processor. The communication interface is configured to a plurality of GNSS signals. The GNSS signals may include at least one almanac value and at least one ephemeris value. The processor is configured to generate a spatio-temporal graph model based on the at least one almanac value, the at least one ephemeris value, and a predetermined offset value for a base location. The spatio-temporal graph model analyzes subsequent GNSS signals to determined a predicted offset or a corrected GNSS position.

Embodiments including a method and apparatus for correction of a global navigation satellite system (GNSS) are described. In one example, the apparatus includes a communication interface and a processor. The communication interface is configured to a plurality of GNSS signals. The GNSS signals may include at least one almanac value and at least one ephemeris value. The processor is configured to generate a spatio-temporal graph model based on the at least one almanac value, the at least one ephemeris value, and a predetermined offset value for a base location. The spatio-temporal graph model analyzes subsequent GNSS signals to determined a predicted offset or a corrected GNSS position.

A tracking loop and associated method for tracking a satellite signal in a GNSS receiver and for determining a line-of-sight (LOS) signal from a plurality of satellite signals received by the GNSS receiver from a satellite. One or more first correlators perform a correlation between a code signal derived from one of the received satellite signals and a plurality of corresponding replica code signals to determine a plurality of code correlation sums comprising a prompt code correlation sum, one or more early code correlation sums and one or more late code correlation sums. One or more second correlators correlate the plurality of code correlation sums with a plurality of replica carrier signals, each having a different Doppler frequency offset, to determine, for each of the plurality of code correlation sums, a set of correlation magnitudes at frequencies of the plurality of replica carrier signals. An LOS identification module identifies the LOS signal based on a signal propagation delay corresponding to one or more local maxima within the sets of correlation magnitudes.

A position-determining apparatus, such as a GPS receiver, determines the position of the mobile device based on the time of flight of a transmitted probe signal using a method in which sections of the received signal is classified into two or more categories and accumulated according to categories before being used to compute the correlations familiar in the context of a matched filter. Using the method of the present invention to compute the correlations, and optionally applying additional time-saving techniques described herein, a position determination is achieved using arithmetic operations that are significantly reduced from that required in prior art methods to compute the correlations. The reduced number of arithmetic operations can reduce significantly the power consumption required of a device carrying out a method of the present invention, and thereby realizing a significant advantage.

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.

Systems and methods for determining an accurate location of a signal's source of transmission. The methods involve: demodulating a detected carrier signal modulated with a Pseudo Noise (“PN”) code sequence to obtain an original information-bearing signal therefrom; computing time delay offsets using correlations of PN code windows for each symbol of the original information-bearing signal; determining a high accuracy Time Of Arrival (“TOA”) of the detected carrier signal using the time delay offsets; and using the high accuracy TOA to determine an accurate location of the original information-bearing signal's source of transmission.

An assisted satellite positioning system based on detecting signals from a number of satellites includes: (a) a mobile receiver; and (b) a base station communicating with the receiver over a low-power wireless communication network, the base station providing ephemeris data of a selected number of the satellites, but not all, using a compressed data format. The ephemeris data may include data concerning doppler frequency variations or elevation variations of the selected satellites over a predetermined time interval. The doppler frequency variations and the elevation variations may be represented in the compressed format by coefficients of a polynomial function of time. The polynomial function may be weighted to have lesser relative errors in larger doppler frequencies than lesser doppler frequencies, or to have lesser relative errors in lesser elevations than larger elevations. In one implementation, the low-power wireless communication network—such as a LoRa network—that has a range of at least 10 miles.

A demodulator comprises a first-stage carrier demodulator and a second-stage carrier demodulator. The first-stage carrier demodulator is configured to remove or compensate for the tracking error in the baseband signal, where the tracking error comprises aggregate, channel tracking error of carrier phase for the same received band, sub-band, (baseband) GNSS satellite channel, or set GNSS channels. The second stage carrier demodulator is configured to remove or strip a carrier signal component without any unwanted image or carrier-related frequency artifacts and to prepare for correlation-based decoding or demodulation of the encoded baseband signal by the correlators. First correlators are configured to determine correlations for code phase tracking loop, where the code phase tracking loop is configured to estimate a corresponding code error component of the tracking error for the code local oscillator for a respective channel. Secondary correlators are configured to determine correlations for a carrier phase tracking loop, where the carrier phase tracking loop configured to estimate a corresponding aggregate feedback error for multiple channels or a set of channels.

The present invention provides an airborne BeiDou system and method for application thereof, the airborne BeiDou system comprising: an airborne communication navigation monitoring system which integrates a BeiDou application software module of a BeiDou navigation communication sub-system and a BeiDou protocol stack software module; a BeiDou transceiver connected to said airborne communication navigation monitoring system; a BeiDou server connected to said BeiDou transceiver. The present invention can integrate a BeiDou application software module of a BeiDou navigation communication sub-system and a BeiDou protocol stack software module into an airborne communication navigation monitoring system such that the airborne communication navigation monitoring system can, by means of the BeiDou application software module and the BeiDou protocol stack software module, perform data interaction with the BeiDou transceiver and the BeiDou server, thus achieving autonomous airborne communication navigation monitoring in the field of aviation.

The present invention provides an airborne BeiDou system and method for application thereof, the airborne BeiDou system comprising: an airborne communication navigation monitoring system which integrates a BeiDou application software module of a BeiDou navigation communication sub-system and a BeiDou protocol stack software module; a BeiDou transceiver connected to said airborne communication navigation monitoring system; a BeiDou server connected to said BeiDou transceiver. The present invention can integrate a BeiDou application software module of a BeiDou navigation communication sub-system and a BeiDou protocol stack software module into an airborne communication navigation monitoring system such that the airborne communication navigation monitoring system can, by means of the BeiDou application software module and the BeiDou protocol stack software module, perform data interaction with the BeiDou transceiver and the BeiDou server, thus achieving autonomous airborne communication navigation monitoring in the field of aviation.