Systems and methods for use in navigating aircraft are provided. The systems can use Geometry Redundant Almost Fixed Solutions (GRAFS) or Geometry Extra Redundant Almost Fixed Solutions (GERAFS) to compute high confidence error bounds for a heading angle estimate or pitch angle derived using signals received on at least two antennas.

Systems and methods for use in navigating aircraft are provided. The systems can use Geometry Redundant Almost Fixed Solutions (GRAFS) or Geometry Extra Redundant Almost Fixed Solutions (GERAFS) to compute high confidence error bounds for a heading angle estimate or pitch angle derived using signals received on at least two antennas.

A GNSS spoofing signal detection/elimination includes tracking acquired candidate GNSS signals for each target GNSS signal, identifying the acquired candidate GNSS signals as authentic, unauthenticated, or counterfeit, removing the counterfeit GNSS signal(s) from tracking, generating a first list of the authentic GNSS signals and a second list of unauthenticated candidate GNSS signals, creating a plurality of sets of GNSS signals by selecting at least four GNSS signals from among the first list and the second list, such that each set includes all of the authentic GNSS signals, if any, and at least one unauthenticated candidate GNSS signal such that each set includes only one candidate signal per target GNSS signal, calculating PVT solutions and post-fit residuals for each set, thereby obtaining a plurality of estimated solutions, estimating authenticity of unauthenticated GNSS signals by analyzing the plurality of estimated solutions.

Systems and methods for multi-sensor mapping are provided for a multi-sensor device having a range sensor, a location sensor and an orientation sensor that provide range data, location data and orientation data, respectively. The device may be operated in a stationary mode, a mobile ground mode or an airborne mode. The range data, the location data and the orientation data are combined to generate three-dimensional geo-referenced point cloud data.

A method and system are provided. The method includes receiving, by a GNSS receiver, a GNSS signal, rotating, by a carrier rotator, samples of the GNSS signal with carrier phase inputs, inverting, by a chip matched filter (CMF), the rotated samples, and generating, by the CMF, an output based on the inverted samples.

A target tracking device to estimate a position of a target with high accuracy will be provided. The target tracking device is provided with a communication device and a processor. The communication device performs communication with a plurality of observation satellites that observe the target. The processor executes a selection of satellites, a setting of a schedule and an estimation. The selection of satellites includes selecting two or more selected satellites that observes the target among the plurality of observation satellites. The setting of the schedule includes determining an observation schedule for each of the two or more selected satellite to observe the target and transmitting an observation request signal that represents the determined observation schedule to a corresponding selected satellite. The estimation includes estimating the position of the target based on two or more pieces of high-precision observation information respectively observed by the two or more selected satellites.

A target tracking device to estimate a position of a target with high accuracy will be provided. The target tracking device is provided with a communication device and a processor. The communication device performs communication with a plurality of observation satellites that observe the target. The processor executes a selection of satellites, a setting of a schedule and an estimation. The selection of satellites includes selecting two or more selected satellites that observes the target among the plurality of observation satellites. The setting of the schedule includes determining an observation schedule for each of the two or more selected satellite to observe the target and transmitting an observation request signal that represents the determined observation schedule to a corresponding selected satellite. The estimation includes estimating the position of the target based on two or more pieces of high-precision observation information respectively observed by the two or more selected satellites.

A node of a satellite constellation system includes a global positioning receiver configured to receive first signaling from a first plurality of non-LEO navigation satellites of a constellation of non-LEO navigation satellites in non-LEO around the earth. A transceiver is configured to send and receive inter-node communications with other nodes of the satellite constellation system. At least one processor is configured to execute operational instructions that cause the at least one processor to perform operations that include: determining a state of the node of the satellite constellation system based on applying precise point positioning (PPP) correction data to the first signaling, wherein the PPP correction data is received separately from the first signaling; and generating a navigation message based on the state of the node. A navigation signal transmitter is configured to broadcast the navigation message to at least one client device, wherein the client device is space-based, the navigation message facilitating the at least one client device to determine an enhanced position of the at least one client device based on the navigation message.

It is provided a joint receiver and receiving method for navigation signals located at adjacent frequencies. The joint receiving method includes: receiving a first navigation signal and a second navigation signal which are located at adjacent frequencies (S1); and calculating a frequency estimation of a virtual wideband navigation signal constructed based on the first navigation signal and the second navigation signal (S2), wherein the virtual wideband navigation signal is an asymmetric BOC-like navigation signal having a virtual carrier and a virtual sub-carrier. With the joint receiver and joint receiving method, not only power gain but also bandwidth gain can be obtained, and the ranging precision can be significantly improved.

A central location system provides an end-to-end high-accuracy positioning solution that provides navigation, geo-tagging, and general positioning data to receivers. The central location system does this by providing a cloud correction service and a robust positioning engine. For example, the central location system may provide single-frequency receivers with corrections for atmospheric delays and multipath throughout different geographic regions. The central location system computes corrections by leveraging location data from dual-frequency receivers. The central location system may also increase ionospheric delay coverage of portions of a geographic region. With increased ionospheric delay coverage, receivers can compute better location estimates. The central location system may also compute refined location estimates of single-frequency receivers and/or dual-frequency receivers for receivers with limited access to signals transmitted from satellites. The central location system may do this by estimating a receiver's location with respect to the location estimates of other receivers.