摘要:
A method of generating a synthetic pressure altitude is disclosed. The method includes providing a static air temperature to a data processing device. The method also includes providing a geometric altitude to the data processing device. Further, the method includes performing a numerical integration based on the static air temperature and the geometric altitude.
摘要:
A follower aircraft is guided to a lead aircraft using a datalink that determines range between the two. The lead aircraft has an antenna array and processing system for determining azimuth/elevation of the follower aircraft. The lead aircraft transmits a ranging message to the follower aircraft and stores a lead aircraft time of transmit (TOT) time. The ranging message is received at the follower aircraft and a follower aircraft time of reception (TOR) time is stored. A second ranging message is transmitted from the follower aircraft to the lead aircraft and a follower aircraft TOT time is stored. The second ranging message is received at the lead aircraft and a lead aircraft TOR is stored. A message is sent from the follower aircraft when follower aircraft TOT and TOR. The range and time offset is determined by the lead aircraft using follower aircraft TOT/TOR and stored lead aircraft TOT/TOR.
摘要:
A method of generating a synthetic pressure altitude is disclosed. The method includes providing a static air temperature to a data processing device. The method also includes providing a wind velocity, a ground velocity, and a geometric altitude to the data processing device. Further, the method includes performing a numerical integration based on the static air temperature, the wind velocity, the ground velocity, and the geometric altitude. The wind velocity and the ground velocity are used to estimate pressure gradients not included in a static air column model.
摘要:
A method and apparatus for improving differential navigation accuracy uses time transfer over a two-way communications link. The communications link transmits an overall time offset between a differential reference station and a remote user. A differential navigation position solution is modified at the remote user with the overall time offset to improve the differential navigation accuracy. A first time offset between a first communications device and a first navigation receiver at the remote user is determined. A second time offset between the first communications device at the remote user and a second communications device at the differential reference station is determined. A third time offset between the second communications device and a second navigation receiver at the differential reference station is determined. An overall time offset from the first time offset, the second time offset, and the third time offset is computed and used to improve the differential navigation accuracy.
摘要:
A method of generating differentially-corrected smoothed pseudorange data in a differential global positioning system (DGPS) includes generating, at a base station, non-mode specific pseudorange and carrier phase correction data. The non-mode specific pseudorange and carrier phase correction data is then provided to a remote receiver. At the remote receiver, one of a plurality of specific smoothing modes of operation is selected for use in generating differentially-corrected smoothed pseudorange and carrier phase data. The differentially-corrected smoothed pseudorange and carrier phase data is then generated by the remote receiver using the selected one of the plurality of specific smoothing modes of operation, and as a function of the non-mode specific pseudorange and carrier phase correction data received from the base station.
摘要:
A method of generating a differentially corrected pseudorange residual in a differential global positioning system includes tracking at a base station first and second GPS signals, having first and second frequencies, from a first satellite. At the base station, a first pseudorange measurement is determined from the tracked first GPS signal. At the base station, a first smoothed pseudorange measurement is calculated from the determined first pseudorange measurement as a function of both the first and second GPS signals. The first smoothed pseudorange measurement is provided to a remote GPS receiver. The remote GPS receiver calculates the differentially corrected pseudorange residual as a function of the first smoothed pseudorange measurement provided by the base station.
摘要:
An apparatus and method for mitigating multipath interference in a spread spectrum ranging/positioning system receiver is disclosed. Improved peak tracking in the presence of multipath interference is accomplished with an improved discrimiriant. The discriminant may be developed from a curvilinear function based on a minimal number of correlators. Also disclosed is an open loop measurement compensation innovation that compensates for a multipath-induced shift of the correlation function peak. The positioning system receiver may have either one or both of the mitigation features.
摘要:
Attitude of a spinning vehicle is determined by observing at least one of the apparent amplitude modulation and the apparent phase modulation of a navigation signal received from a navigation source. Vectors describing the direction from the vehicle to the navigation source are computed and used to determine attitude relative to the navigation source. Inertial sensors are demodulated to remove rotation artifacts and used to anticipate rapid maneuvers.
摘要:
A method for providing collaborative PNT for a plurality of nodes in a distributed sensing system is disclosed. The method may include receiving carrier phase and pseudorange measurements from a first node and a second node of the plurality of nodes; providing a process model for each node, where the process model for each node is configured for modeling error characteristics associated with that node; determining an error covariance between the first node and the second node; and estimating a PNT solution for the first node and a PNT solution for the second node based on: the carrier phase and pseudorange measurements received from the first node, the carrier phase and pseudorange measurements received from the second node, the process model for the first node, the process model for the second node, and the error covariance between the first node and the second node.
摘要:
The present invention is a geolocation system for providing coordinated sensing and precision geolocation of a target emitter. The system may include a Quint Networking Technology (QNT) subsystem which may be configured receiving, detecting and identifying a target emitter signal. The QNT subsystem may be further configured for extracting a carrier phase of the signal. The system may further include a Real Time Kinematic Global Positioning System (RTK GPS) subsystem for determining a position of the geolocation system relative to a position of a second geolocation system. Further, the system may be configured for communicating with the second geolocation system via a QNT communication data link for: determining a QNT time difference via signal carrier phase differencing for calculating a time difference between the geolocation systems and geolocating the target emitter based on both the relative position information of the geolocation systems and the calculated time difference between the geolocation systems.