Abstract: Apparatus for measuring surveying parameters, such as distances and angular displacements between an instrument survey station and a mobile survey station, with improved accuracy. The invention combines a differential satellite positioning system (DSATPS), available with positioning systems such as GPS and GLONASS, with electromagnetic measurements of distances and optically encoded angles by a conventional electro-optical survey instrument to provide survey measurements that can be accurate to within a few millimeters in favorable situations. The DSATPS relies upon pseudorange measurements or upon carrier phase measurements, after removal of certain phase integer ambiguities associated with carrier phase SATPS signals. The SATPS may be retrofitted within the housing of the conventional electro-optical instrument. In a first approach, a remote station provides DSATPS corrections for the mobile station and/or for the instrument station.

Abstract: A method of generating a noise estimate during seismic surveying, including measuring noise energy having a plurality of frequencies in a second time interval. The second time interval having a second start time delayed from a first start time of a first time interval during which a first plurality of reflected seismic signals are present. The plurality of reflected seismic signals having the plurality of frequencies. The second time interval approximately concurrent with the first time interval to measure one of the plurality of frequencies of the noise energy different than one of the plurality of frequencies of the first plurality of reflected seismic signals that are present. A noise estimate is generated based on the noise energy measured.

Abstract: A Global Positioning System (GPS) receiver employs variable spacing of Doppler offset bins and code offset bins when acquiring a P(Y) code, to improve signal acquisition characteristics with respect to a search region having a plurality of Doppler offset bins and code offset bins. The receiver includes an acquisition module in which an input signal representative of a received P(Y) code is received and applied to a first programmable rate mixer. An output of the first programmable rate mixer is applied to a combiner, which selectively combines samples of the input signal based on a control input to dynamically determine the spacing of the code offset bins. An output of the combiner is normalized and applied to a correlation unit, which generates correlation measures of the received P(Y) code and a locally generated P(Y) code. A signal representative of the correlation measures is applied separately to each of a set of programmable rate mixers and mixed with separate mixing signals.

Abstract: The junction box of the present invention allows a user to couple multiple electronic devices to a primary electronic device. The junction box includes a housing assembly made up of an upper housing and a lower housing. The upper housing fits over the lower housing so as to form an enclosure. A seal assembly forms a seal between the upper housing and the lower housing. The upper housing extends outward on one side so as to form an overhanging portion and an opening. The overhanging portion, along with the seal assembly prevents fluids, dust and foreign particles from entering the enclosure. A circuit board is disposed in the enclosure that is coupled to a primary electrical cable. The primary electrical cable connects to the back of a primary electronic device. Electronic devices that are to be coupled to the primary electronic device are coupled to the junction box via cables that connect to each electrical device and connect to the circuit board.

Abstract: A method and apparatus that allows for safely operating a vehicle when an automatic steering control feature of a guidance control system is in operation. One or more sensors are used to determine whether the operator is in the vehicle. If the sensors detect that the operator has left the vehicle, the vehicle is shut off. The safety system includes one or more software programs that operate to determine whether the guidance control system is operating properly. More specifically, a control unit is coupled to the microprocessor and the steering control mechanism for determining whether or not an error condition has occurred. In the event that an error condition has occurred, the guidance control system is disengaged and control of the vehicle is turned over to the operator. In one embodiment, the safety system determines whether the operator is ready to take control of the vehicle prior to disengaging the guidance control system.

Abstract: A GPS receiver and an RF GPS integrated circuit for receiving a GPS signal. The GPS integrated circuit includes a synthesizer for generating LO signals, first and second downconverters for using the LO signals for downconverting the GPS signal, and a sampler for providing in-phase and quadrature phase sampled output signals representative of the GPS signal. The synthesizer includes a multi-mode divider for providing substantially the same first LO frequency at about the midpoint of the L1 and L2 GPS lo frequencies for either of two reference frequencies. The RF GPS integrated circuit uses an entirely on-chip voltage controlled oscillator (VCO) having a resonator for generating the LO signals and an entirely on-chip filter for filtering a first intermediate frequency signal.

Abstract: A GPS (Global Positioning System) aircraft guidance system for use with circular cultivated agriculture fields. The system of the present invention includes a GPS receiver adapted to determine a present position, ground track, and ground speed of an aircraft. The GPS receiver is also adapted to store a configuration of a circular cultivated agricultural field and to compute a desired flight path for achieving an optimal coverage of the field. Deviations of the aircraft from the desired flight path are also determined. The GPS receiver is further adapted to generate a dispense signal which indicates when to dispense agricultural chemicals from the aircraft. A guidance indicator is coupled to the GPS receiver for providing guidance information to the pilot. The guidance indicator is adapted to indicate the aircraft's deviation from the desired flight path and indicate whether the dispense signal is asserted.

Abstract: A system for monitoring location and speed of a vehicle, using a location determination system such as GPS, GLONASS or LORAN and an optional odometer or speedometer, for determining and recording the locations and times at which vehicle speed is less than a threshold speed for at least a threshold time (called a “vehicle arrest event”). Vehicle arrest event locations, times and time intervals are stored and/or printed to provide trip and mileage records and for efficiency monitoring. A vehicle odometer and/or speedometer can also be calibrated and/or corrected using this approach.

Abstract: An integrated position and direction system is disclosed that includes a digital compass, wherein the digital compass includes at least three sensors, and a satellite positioning system having a receiver adapted to receive satellite position determining signals. Direction is determined using the digital compass and heading is determined using the SATPOS. When the integrated position and direction system is moving, heading is indicated. When the integrated position and direction system is not moving direction is indicated. The integrated position and direction system automatically switches between the display of heading (when the integrated position and direction system is moving) and the display of direction (when the integrated position and direction system is not moving).

Abstract: An integrated position and direction system is disclosed that includes a digital compass and a satellite positioning system having a receiver adapted to receive satellite position determining signals. Direction is determined using the digital compass and heading is determined using the SATPOS. When the integrated position and direction system is moving, heading is indicated. When the integrated position and direction system is not moving direction is indicated. The integrated position and direction system automatically switches between the display of heading (when the integrated position and direction system is moving) and the display of direction (when the integrated position and direction system is not moving).

Abstract: A survey system and method for determining the best source of position data for a particular application. The system includes both an optical unit and a satellite positioning system (SATPS) unit for obtaining position data. The optical unit includes a theodolite and an electronic distance meter for determining the position of a rover unit. The SATPS unit includes a SATPS antenna and a SATPS receiver for receiving signals from satellites of the SATPS and a radio for coupling the received signals to the rover unit. The present invention automatically determines the best source of position data. The best source of position data is then used to calculate the position of the rover unit.

Abstract: A precision approach capable dual differential global positioning system (DGPS) receiver avionics system. The system of the present invention includes a first and a second DGPS receiver. The first and second DGPS receivers are both adapted to interface with an autopilot in an aircraft. The DGPS receivers each determine the position of the aircraft as the aircraft proceeds along a flight path. Both DGPS receivers are further adapted to employ carrier aiding to smooth the code phase measurements used in determining the position of the aircraft. Within a predetermined range along the approach path of the aircraft and when the output of the first DGPS receiver and the output of the second DGPS receiver are proximate within a predetermined distance, the DGPS receivers determine a transition point. After the transition point, the DGPS receivers utilize DGPS carrier phase tracking to determine the position of the aircraft relative to its position at the transition point.

Abstract: An improved GPS navigation receiver for converting range and range-rate information from microwave radio transmissions from orbiting satellites and for determining a position of the receiver from a processing of the information and an output connected to provide the determined position on a display. The improvement comprises a database of maps stored in a portable document format (PDF) file independent of any hardware, software and operating system used to create it. The PDF file provides for a description of documents including any combination of text, graphics and images in a device-independent and resolution-independent format. The database is connected to output selected ones of the maps on the display with hypertext access on points-of-interest.

Abstract: A global positioning system (GPS) controlled marking apparatus for staking and a method of using the apparatus to stake a surface. The apparatus uses a standard architectural or other surface site application program and a stakeout driver program in a standard computer and includes a GPS receiver, a stakeout tool, an autopilot, a vehicle, a geographical drawing converter, and a location comparator. The geographical drawing converter converts an image of a drawing pattern to geographical mark locations. The autopilot guides the vehicle to the geographical mark locations. The location comparator detects a location march between the geographical mark locations of the drawing pattern and a current geographical location determined by the GPS receiver. Information for the location match is used by the stakeout tool for driving a stake into the ground.

Abstract: A signal conversion device that provides RTCM correction data to a position determination device. The signal conversion device receives RTCM signals that are converted into a frequency adapted to be received by a position determination device so as to produce a converted correction signal. In one embodiment, the signal conversion device also converts the received RTCM correction data into a format that is adapted to be received by the position determination device. In one embodiment, the received RTCM signal is converted into is the Wide Area Augmentation System (WAAS) format. Alternatively, the signal is converted into a different format such as a particular manufacturer's own format. The converted correction signal is coupled to a position determination device via a wireless link. The position determination device uses the RTCM correction data contained in the converted correction signal for accurately determining position.

Abstract: A method and a system for reprogramming a closed device are disclosed. In one embodiment, the system contains an external memory coupled to a limited access device. The limited access device includes a processor, an internal memory, a select control circuit, an internal data bus, and an external data bus. The internal memory is not accessible except through predefined input and output ports of the select control circuit, which are accessible external to the closed device. The select control circuit selects the external memory as primary memory in response to assertion of a control signal and selects the internal memory as primary memory in response to deassertion of a control signal. The internal data bus transports data within the limited access device which includes the internal memory and the select control circuit and the external data bus transports data between the select control circuit and the external memory.

Abstract: The apparatus and the system for precise vertical navigation of a grading machine in profile of a curved job site terrain is disclosed. The system includes an integrated satellite navigational receiver and a laser detector system. A plurality of laser systems generates a plurality of laser beams covering the curved job site terrain. The laser detector system mounted in the grading machine latches on a single laser beam at each location of the grading machine to obtain the precise vertical coordinate of the grading machine.

Abstract: An infrastructure for implementing DGPS virtual reference stations is disclosed. The virtual reference station infrastructure is comprised of a network of real DGPS reference stations coupled to a central computer system. The real DGPS reference stations may be coupled to the central computer by a set of radio receivers that transmit the pseudorange corrections from each real reference station to the central computer system. The central computer system processes the pseudorange corrections from all the real DGPS reference stations to generate a dynamic satellite error vector and a clock error for each satellite. The dynamic satellite error vector and satellite clock error for each satellite are transmitted to plurality of “virtual” references stations. The virtual reference stations combine the dynamic satellite error vector and the satellite clock error with a local position to generate the local pseudorange corrections (PRC) for the observable satellites.

Abstract: The system and method for long baseline RTK survey are disclosed. The system includes a primary base station (PBS), a secondary base station (SBS), a primary data link between the PBS and the SBS, and a secondary data link between the SBS and a rover. The PBS, the SBS, and the rover are equipped with satellite antennas for satellite navigational purposes. The long baseline vector between the PBS and the rover is established by combining the primary baseline vector between the SBS and the PBS and the secondary baseline vector between the SBS and the rover. The PBS is placed in a position with a known location. The final SBS position is accurately determined using the PBS position during two initialization steps.

Abstract: A system for assuring the location integrity of a decryption chip used to receive and decrypt encrypted signals ES received from an encrypted signal source. The decryption chip operates in association with a licensed signal receiver and is licensed for use at a selected site or location Li and is positioned adjacent to a Satellite Positioning System (SATPS) antenna and receiver/processor that determine the present location L of this antenna. If the SATPS-determined location L is within a region R(Li;di), centered at the location Li and having a selected diameter di, and if the signal ES is associated with a channel that is authorized for reception by this signal receiver, the decryption chip is enabled, and the signal ES is decrypted for audible or visual display on the signal receiver. Otherwise, the decryption chip does not decrypt the incoming signal ES. The licensed site location Li can be changed and the group of channels for which signal receipt and decryption is authorized can be changed.