Abstract: A method for estimating two or three location coordinates and/or receiver time offset for a receiver that receives and analyzes timed signals transmitted from one, two or three non-geosynchronous satellites (GPS, GLONASS, modified LEO, etc.). Combinations of pseudorange, Doppler shift and/or first time derivative and/or second time derivative of Doppler shift are determined and used to estimate the location coordinates and/or receiver time offset.

Abstract: A integrated position determination network including a position determination system and a radio relay system is disclosed which locates the precise location of the position determination system. The position determination system incorporates the radio, the power source and the GPS receiver and all necessary electronics into a single housing. Similarly, all of the components of the radio relay are integrated into a single housing. Many of the components of the position determination system and the radio relay system are interchangeable. Thus, a position determination system and radio relay system which use common components is obtained. The use of common components lowers the cost of manufacture and the cost of maintenance. In addition, interchange ability of components allows for great flexibility in designing a GPS network and in performing real time kinematics operations.

Abstract: An extensible Global Positioning System (GPS) receiver system is described. The receiver system isolates user application processing from time critical GPS acquisition and tracking processing in order to insure that GPS acquisition and tracking processing is timely performed. Thus user application processing can be developed without concern of conflict with GPS acquisition and tracking processing.

Abstract: A handheld survey device includes a Global Positioning System (GPS) receiver for receiving position information, a pointer to point to the location to be measured, a measuring device to measure the distance between the handheld device and the location to be measured and a level and heading device to determine the level and heading of the handheld device. The GPS receiver may be a real time kinematic (RTK) GPS receiver and may be augmented by the use of a dead reckoning (DR) positioning unit. A processor located within the handheld device computes the position of the location using the position information provided by the GPS receiver and/or the DR system, the distance measured between the handheld device and the location, and the level and heading information. The position computed meets the stringent accuracy requirements dictated by survey applications without the use of a range pole.

Abstract: A system for monitoring operation and location of a moving first vehicle relative to a second vehicle. A minimum separation distance between the first and second vehicles is estimated, based on the first vehicle velocity, and optionally on the second vehicle velocity, using location determination (LD) signals received from satellite-based transmitters from GPS, GLONASS and LEO satellites, or from ground-based signal sources such as LORAN signal towers, and using ranging signals from SONAR, RADAR or a similar system. The minimum separation distance is compared with the actual separation distance at selected times, and a vehicle driver is advised if the actual separation distance is too small, if the separation distance is decreasing too quickly, or if the second vehicle velocity is decreasing too quickly. The second vehicle may travel in the same traffic lane, in an adjacent lane, or on a road that intersects the road used by the first vehicle.

Abstract: The present invention comprises a global positioning system (GPS) based augmented reality (AR) aircraft collision avoidance system. The system of the present invention includes a GPS receiver for receiving GPS signals and determining a present position using the GPS signals. The system of the present invention also includes an automatic dependent surveillance (ADS-B) receiver for receiving an ADS-B signal from an aircraft. The system of the present invention further includes an AR visor coupled to both the GPS receiver and the ADS-B receiver. The AR visor receives the present position from the GPS receiver and receives the ADS-B signal from the ADS-B receiver. Using the present position and the ADS-B signal, the AR visor determines a three dimensional bearing to the aircraft. The AR visor is adapted to be worn by a user.

Abstract: Methods for estimation of the relative locations (baseline vectors) of two or more GPS signal antennas relative to each other and for estimation of line biases associated with each signal processing channel associated with each GPS signal antenna. Double difference carrier phase signal measurements are formed, using floating integer and fixed integer solutions for the phase integer ambiguities, and baseline vectors between the GPS signal antennas are estimated. Single difference phase integer ambiguities are obtained and approximations for line biases are computed. Single difference carrier phase measurements are used to estimate baseline vectors and line biases, using fixed phase integer ambiguities with the estimated baseline vectors and line biases as initial conditions, and are processed by Kalman filtering or other suitable signal processing. Angular orientation or attitude of a vehicle body on which the GPS signal antennas are placed is determined from the baseline vectors.

Abstract: A system and method for determining which of a plurality of correction signals is to be used in a position determination system for determining position. An antenna receives broadcasts of correction data on designated frequencies. The received correction data is analyzed to determine the best correction data signal to use to accurately determine position. The correction data from the selected best source of correction data is coupled to a position determination system for accurate determination of position. Thus, the present invention provides a seamless correction system that determines the best source of correction data from available sources and uses the selected correction data to determine location. The seamless correction system updates the source of correction data automatically.

Abstract: Methods for GPS-assisted determination of location coordinates of a mobile user or selected position on or adjacent to the Earth's surface with improved accuracy. Elevation readings from an altimeter or barometer are integrated with readings of the GPS-determined elevation coordinate for that location, using Kalman filter techniques, minimum least square techniques, or comparison of certain statistically defined parameters associated with the altimeter and GPS variables, such as the standard deviation of the expected errors in these variables. The resulting elevation coordinate may be a statistical blend or filtered blend of the altimeter value and a GPS-determined value for the elevation coordinate; or this resulting elevation coordinate can be chosen to be one or the other of these values, based upon comparison of time varying statistical parameters corresponding to the altimeter and the GPS.

Abstract: A number of laser beam stations emit vertically separated parallel planes and/or ray-planes of laser light that can be discriminated by their respective plane elevations, modulation of the laser light, time synchronizing, etc. Identifying the laser plane would also imply an identification of the source laser beam station, and thus a precise indication of the elevation at the point of optical intercept. Alternatively, a single laser beam station is used that can emit several different monochromatic color planes and/or ray-planes of laser light. Monochromatic laser diodes, for example, are used for point-light sources and rotating or on-end conical mirrors are used to convert the diode laser light to the required monochromatic color planes and/or ray-planes of laser light.

Abstract: A position identification system, that employs satellite navigational or similar positioning technology is provided. The position identification system eliminates the need for estimating the location of a desired position and iteratively adjusting the placement of a range pole. In one embodiment, the position identification system includes an antenna/receiver for receiving position signals from a positioning system; an orientation device that is configured to rotate about a first axis and a second axis; a pointing element that operates in conjunction with the orientation device to identify a desired position; and a processor that is coupled to the antenna/receiver to receive the position signals. The processor computes a current position of the position identification system based upon the position signals and directs the orientation device based upon the current position and the desired position.

Abstract: A method for determining an improved position fix by performing postprocessing on a realtime differentially corrected GPS position. A remote rover unit containing a GPS receiver is used to determine a differentially corrected position according to measured pseudoranges and realtime pseudorange correction vectors is broadcast by a base station. The rover unit applies realtime corrections to measurements to determine a more accurate realtime differential position. It then stores the realtime differential position and the realtime pseudorange correction vector. Subsequently, postprocessing is performed to determine a postprocessed pseudorange correction vector. A difference vector representing the difference between the realtime pseudorange correction vector and the postprocessed pseudorange correction vector is then determined. This difference vector is applied to the realtime differential position to calculate a more accurate, improved position fix.

Abstract: An apparatus and a method of purchasing or leasing the time dependent option of operation of an instrument are disclosed. An apparatus generates and uses a time dependent password configured to be matched with at least one time dependent parameter in order to activate the instrument. The apparatus includes a time-antispoof device in order to prevent spoofing the purchased time of operation of the instrument. The time-antispoof device includes a satellite navigation receiver in order to enforce the antispoof option.

Abstract: Apparatus and method for a location determination and reporting (LDR) system for clandestinely or surreptitiously determining and reporting a missing vehicle present location. The vehicle may be stationary or moving and may be anywhere within reach of a cellular central station to which the location is reported. The vehicle is equipped with a location determination (LD) unit (preferably hidden on the vehicle) that receives LD signals and determines the LD unit present location, a specially configured cellular telephone, and a call interceptor. When the vehicle is reported missing, a central station or the vehicle operator interrogates the vehicle LDR system by transmitting a location interrogation signal, commanding the LD unit to transmit its present location. The vehicle phone does not signal receipt of an incoming call for an initial time period of selected length .DELTA.t.sub.d, awaiting possible receipt of a location interrogation signal.

Abstract: A method and apparatus for providing orientation using a solar sighting device. In one embodiment, sighting of the sun and the moon and stars is used to determine orientation. The input from the solar sighting system is input into a processing system along with global positioning system data. Ephemerides stored in the processing system are used in conjunction with time signals from global positioning system data and position determined from global positioning system data so as to determine orientation. This orientation is then used to determine the direction of movement in a vehicle navigation system and is used to orient an optical sighting system.

Abstract: Method and apparatus for tracking the location of, and for providing cellular telephone handoff for, a mobile cellphone user as the user moves from one cell to another. A boundary curve B12 between a first cell and an adjacent second cell is defined in an electronic map. First and second quasi-boundary curves QB1 and QB2, lying within the first and second cell, respectively, are defined, where each point on the curve QBi (i=1,2) lies at a selected distance from the boundary curve B12. A common region CR12 of points lying between the quasi-boundary curves QB1 and QB2 and including the boundary curve B12 is defined. The present cellphone location of the cellphone user is determined using a location determination system, such as GPS or GLONASS or a ground-based system. Cellular telephone service for the cellphone user is provided by a first cell site or by a second cell site, when the cellphone user is located within the first cell or the second cell, not including the overlap region CR12.

Abstract: A new and useful method and apparatus are provided for collecting, recording and displaying data pertaining to artifacts in a time based fashion. The apparatus includes a data measurement device such as a GPS receiver or other measurement device for collecting data such as position information pertaining to artifacts, a memory for recording collected data and a user interface having an input for receiving recorded information such as qualitative information pertaining to artifacts from the user and a display for displaying the collected data as it is collected by a user. The user interface includes a time scale to associate the data collected pertaining to the artifacts with the time at which the data was collected providing a useful project management tool for the user as well as for management personnel supervising the user and for providing an accurate time based archival record of data pertaining to artifacts such as their location and physical condition.

Abstract: An aircraft turn guidance system comprises a satellite navigation receiver connected to a turn path computer. Position, velocity and waypoint headings and distances are communicated from the satellite navigation receiver to the turn path computer. Roll angle, airframe and airspace constraints are fed to the turn path computer which computes a constant roll turn for the constraints when transitioning a waypoint from the inbound to outbound legs. The effects of wind on the airmass are computed in to account for real world conditions.