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 GPS receiver and method using alternating “A” and “B” integration time segments. The polarities of certain GPS data bits are known beforehand and their expected reception times are known. The GPS signal in 10 millisecond “A” time segments and “B” time segments is depolarized according to the known polarities. The depolarized GPS signal during an “A” time period made up of all the “A” time segments is integrated for providing an “A” time period magnitude for each code phase. Likewise, the depolarized GPS signal during a “B” time period made up of all the “B” time segments is integrated for providing a “B” time period magnitude for each potential GPS code phase. The strongest of the time period magnitudes is compared to a correlation threshold for selecting a code phase for signal acquisition.

Abstract: A method and system for variable data rate transmission in a real-time kinematic (RTK) positioning system. An RTK positioning system having a reference station and a rover utilizes wireless communications for data transfer. The data transmission rate between the reference station and the rover is dynamically controlled by a programmable transmission controller. The transmission rate is determined on the basis of specific parameters. Parameters that may be used to determine the data transmission rate include rover demand, required rover accuracy, satellite positioning system (SATPS) events, the required data for ambiguities, and the type and content of the data transmitted.

Abstract: A method and system for sending messages that indicate position. In one embodiment, the message transmission device includes a message transmission unit that is coupled to a position determination system. A server is adapted to receive messages from the message transmission device. In operation, a first message is generated at the message transmission device. The position of the message transmission device is determined and is included in the message. The message is then sent to the server. The server then generates a second message that complies with any instruction indicated in the first message that relates to position. An instruction that relates to position can indicate routing, format, performance of a task, etc. By indicating return routing in the instruction, a user can obtain location in any of a number of desired formats without the need to store extensive databases in the message transmission device.

Abstract: Apparatus and methods for determining the timing of the data bit transitions. “N” assumptions of data bit transitions are used for determining N integrations of an incoming spread signal for data bit time periods where N is the data bit time period divided by the code time period. In a first variation, the N assumptions use N start times separated by code time periods. In a second variation, the N assumptions use N sign inversion times separated by code time periods. In either variation the unsigned values of the N integrations, respectively, may be combined for several data bit time periods. The assumed transition timing that results in the strongest of the N integrations is indicative of the timing of the data bit transitions.

Abstract: A method for monitoring of the substitution at least one high quality position measurement with a set of upgraded low quality position measurements comprising the steps of: (A) selecting a high quality source of position measurements of the object from a group of high quality sources; (B) obtaining at least one high quality position measurement of the object by using the high quality source; (C) saving at least one high quality position measurement of the object; (D) obtaining at least one low quality position measurement of the object by using a low quality source; (E) substantially continuously monitoring and checking if the currently available high quality position measurement of the object is of substantially high quality; (F) if at least one currently available high quality position measurement of the object is of substantially high quality, using at least one high quality position measurement of the object for navigation purposes of the object; (G) if the currently available high quality position measur

Abstract: A guidance control system is configured to control the positioning and spatial orientation of a digging implement mounted on a frame of an trenching machine for working a subsurface of earth to a desired trench profile. The position of a dynamic cutting edge of the digging implement is monitored and then controlled so that the sensed dynamic cutting edge position is equal substantially to the calculated dynamic cutting edge position. The guidance control system includes sensors, a processor, and accessible memory providing digital design information regarding the desired trench profile.

Abstract: This invention relates to improving the signal-to-noise ratio of semi-codeless tracking by presenting a method and apparatus which employs an optimal W-code timing pattern, and/or provides signal-to-noise gain by adding L1 and L2 W-code bit timing estimate signals before combining the L1 W-code estimate signal with the L2 W-code estimate signal.

Abstract: A position determination system for movable objects or personnel comprising at least one portable position sensor built into a wearable item of a member of personnel having an identification number, or embedded into a movable object having an identification number, and a high accuracy position determination device. The high accuracy position determination device is configured to provide a set of high accuracy initialization data including a set of high accuracy absolute positional data indicative of location of the initialization device, a set of high accuracy velocity/acceleration data indicative of velocity/acceleration of the initialization device, and a set of high accuracy orientation data indicative of orientation of the high accuracy position determination device.

Abstract: A three dimensional structure is precisely positioned at a desired location. A viral model of the structure of interest is created and stored in a computer memory. Some time later, remote sensors are placed in selected positions on the structure of interest. The sensors are configured so as to provide real time location, attitude and orientation information regarding the structure and may consist of GPS remote units, tilt meters, gyro compasses, and pressure sensor. The position of each the remote sensors on the actual structure is also recorded in the computer memory so that the virtual model accurately reflects the configuration of the structure. As the structure is being positioned, the real-time location, attitude and orientation information produced by the remote sensors is monitored at a base station and used to update the virtual model. In this way, the virtual model accurately reflects the current location, attitude and orientation of the structure.

Abstract: A method for standard positioning service (SPS) and precise positioning service (PPS) cooperative operation is disclosed. In one embodiment, a positioning signal is received. A PPS data portion of the positioning signal is acquired with a PPS receiver. An SPS data portion of the positioning signal is acquired with an SPS receiver. The PPS receiver and the SPS receiver are then communicatively coupled. The PPS data portion from the PPS receiver is then cross-validated with the SPS data portion from the SPS receiver, wherein the cross validation of the PPS data portion and the SPS data portion provides information about the validity of the positioning signal.

Abstract: The present invention provides a radio navigation emulating GPS device. In one embodiment, the radio navigation emulating GPS device receives an identifier associated with a conventional radio navaid. The present radio navigation emulating GPS device then retrieves latitude and longitude information corresponding to the received conventional radio navaid from a database. A satellite based position information system generates position information for the aircraft on which the present radio navigation emulating GPS device is disposed. The present radio navigation emulating GPS device then generates navigation information for the aircraft using the retrieved latitude and longitude information and the satellite based position information for the aircraft. The present radio navigation emulating GPS device then presents the navigation information in a manner which emulates the presentation of navigation information generated by a conventional radio navigation device.

Abstract: A method and system for dynamically targeting content (e.g., advertising) displayed by a moving vehicle according to the location and direction of travel of the vehicle. Multiple items of content are loaded onto the vehicle and updated at periodic intervals. Position information (such as Global Positioning System information) is used to determine the location and direction of travel of the vehicle. Using the vehicle's position and direction of travel, and perhaps the time of day, a particular item of content can be selected and displayed to an audience external to the vehicle. The amount of time each particular item of content is displayed can be measured and used as the basis for billing clients.

Abstract: A GPS receiver for integrating a GPS signal separately in a series of “A” type and “B” type time segments, the “A” segments alternating with the “B” time segments; combining the squares of the magnitudes of “A” time segment integrations corresponding to code phases for forming “A” type combined magnitudes; combining the squares of the magnitudes of the “B” time segment integrations corresponding to code phases for forming “B” type combined magnitudes; and determining an acquisition code phase of the signal from the strongest of the “A” or “B” combined magnitudes. The “A” time segments and the “B” time segments are one-half the period of the data bits of the signal, thereby ensuring that either the “A” time segments or the “B” time segments avoid the nullifying effect of data bit inversions.

Abstract: A vehicle fleet management information system for identification of location and direction of movement of each vehicle in the fleet in real-time and automatic communication directly with management offices to report its location and heading, and status of predetermined events in which the vehicle may be engaged. One example is a cement delivery truck which monitors location, speed and status information such as start pour, pouring, end pour, wash and leave job, and automatically transmits this information with a management office without requiring affirmative action by the vehicle operator.

Abstract: A device for spatial positioning systems includes a programmable measurement filter that is dynamically tuned by the device signal processing unit. The signal processing unit analyzes available data including the measurement signal to determine the likelihood that a detected measurement comprises true device movement and adjusts the measurement filter bandwidth accordingly.

Abstract: A satellite positioning system (SATPS) receiver has a mix of standard and enhanced digital channel processors. The standard digital channel processors perform continuous tracking. During a low SNR and/or fast acquisition mode, the enhanced digital channel processor accumulates samples of a SATPS signal that are identically positioned within corresponding PRN code repetition periods, and plays back the stored accumulated values of the samples in an integration period to a correlation section for correlation with a locally generated PRN code.

Abstract: An indoor GPS clock using GPS signals lower that ?143 dBm for issuing disciplined frequency and time standard signals. The indoor GPS clock includes a correlation machine using long integration periods for enabling the indoor GPS clock to operate with low signal levels; a carrier-less tracking loop for tracking the low level signals without carrier offset feedback, a clock bias loop for providing clock bias feedback; and a reference oscillator using the clock bias feedback for providing disciplined frequency and time signals having greater accuracy than is available in conventional GPS positioning receivers. The indoor GPS clock also includes a holdover driver providing compensation for predicted drift in clock bias error for disciplining the reference oscillator for several hours when the GPS signal is no longer being received.

Abstract: A method and system for communication in a real-time kinematic (RTK) positioning system by paging. An RTK positioning system having a reference station and a rover utilizes a paging system for data transfer. A single satellite positioning system (SATPS) reference station may be coupled to the paging system to provide RTK correction data, or multiple networked reference stations may be coupled to the paging system to provide data. Paging systems using allocated paging bands having fixed width channels (e.g. 20 kHz) such as those between 35 MHz and 36 MHz or 43 MHz and 44 MHz may be used.