Abstract: A lane change alarm using data for a highway track. A highway track database provides geographical location points for a track of a highway lane. A differential global positioning system (DGPS) receiver provides a vehicle location. A longitudinal track matching code matches the vehicle location against a track location and provides a longitudinal direction and a transverse distance to an alarm gate. The alarm gate indicates an alarm condition unless a lane change signaler is operated for indicating that the lane change is intentional. The highway track database is created using a similar DGPS receiver by determining and recording highway track location points for a selected highway lane while driving on the highway lane.

Abstract: A method and apparatus for accurately positioning a tool on a mobile machine are provided. The machine is equipped with a satellite positioning system (SPS) receiver, a robotic total station with an integrated scanning laser and a storage facility storing a digital terrain model (DTM) of a work area. The machine operates within the work area and a number of stationary reflectors are positioned at various locations about the work area. The SPS receiver determines the current location of the machine. A system controller then references the DTM to determine the closest stationary reflector to the current location of the machine. Location data of the closest reflector is then provided to the robotic total station, which locates the closest reflector. The scanning laser then locks on to the reflector and the system controller determines the angle between the laser and the reflector.

Abstract: The real time differential satellite navigational system integrated with the tilt measurement system is disclosed. The integrated positioning system allows one to perform the real time precise navigation of a mobile unit in a variable tilt environment. In another embodiment, the map generating system is disclosed. The map generating system utilizes the low cost post-processing differential GPS receiver. The map generating system allows one to record the map of an actual area covered by a mobile unit in a variable tilt environment.

Abstract: Methods for chaining together two or more navigation or survey stations to complete a project, where only adjacent stations in the chain have contact with each other. The location of a mobile reference station is determined and corrected, if necessary, using location determination (LD) signals from an LD system such as GPS, GLONASS, LEO or the like. The location of a first rover station is determined using RTK information and signal differencing from the mobile reference station. The location of a second rover station is determined using RTK information and signal differencing from the first rover station, in a chain of location determinations. Standard electronic distance measuring equipment and techniques can be used to supplement these methods in an integrated approach. Location consistency checks are provided by using RTK analysis to redetermine the location of one or more preceding stations in the chain.

Abstract: A surveying device includes a global positioning system (GPS) receiver unit configured to provide first positioning information signals; a dead reckoning (DR) unit configured to provide second positioning information signals; and a geographic information system (GIS) data collection unit configured (e.g., through appropriate software) to collect GIS data using the first and second positioning information signals. The GPS receiver unit may be a differential GPS receiver unit or a real time kinematic (RTK) GPS receiver unit. Examples of GPS receiver units that may be configured in accordance with the present invention include the Trimble GPS Pathfinder Pro XR unit and the Trimble Placer GPS unit. The GIS data collection software may be Trimble ASPEN or Trimble Asset Surveyor.

Abstract: An integrated radio direction finding and GPS receiver tracking system. In one embodiment, a transmitter device is attached to an object to be located. The transmitter device transmits a signal. The transmitted signal is received by a portable, user-totable tracking unit. The portable, user-totable tracking unit uses the received signal to determine at least the bearing of the object from the portable, user-totable tracking unit. A position generating system is coupled to the portable, user-totable tracking unit to generate the position information of the portable, user-totable tracking unit. The bearing of the object from the portable, user-totable tracking unit and the position information of the portable, user-totable tracking unit is transmitted from the portable, user-totable tracking unit to a base station.

Abstract: Methods and apparatus which enable use of augmented vision in survey procedures and related work. Virtual objects are presented to an operator on a see through display. Some of the objects correspond with real objects in the operators field of view at any instant and others may provide interactive functions for the operator. The operator eye positions are determined using measurements from a remote positioning system such as GPS, an operator head orientation sensing system, and knowledge of head geometry. Positions and attributes of real objects are stored in a database memory carried by the operator. The operators field of view is continuously determined and images of the real objects are generated from database information by a rendering system. The images are presented on the see through display as virtual objects. Numerous functions may be provided for the operator using virtual interactive objects, depending on the work at hand.

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: Methods and apparati for representing and storing a sequence of digital data values so that, once stored in memory, a data value cannot be modified, or cannot be modified without detection. Detection of subsequent data alteration may use error checksums, storage of instrument data in different data fields, data constraint relations, data encryption techniques and/or comparison of instrument identification numbers. Where data are to be stored in non-alterable form, the number of elements used in representing the sequence is reduced or minimized. A data value sequence can be supplemented by one or more additional data values that are received and similarly stored, without changing any of the sequence of data values already stored. The instrument data values can be individual readout values or can be accumulated sums of data values. Some of the methods are exact, allowing reconstruction of any data value with zero error. Other methods are approximate but are less complex to apply.

Abstract: A method and apparatus for indicating the time and location at which audio signals are received by a user-carried audio-only recording device. In one embodiment, audio signals are received at a receiver of a user-carried audio-only recording device. A position determining system generates position information indicative of the location of the portable user-carried audio-only recording device when the receiver of the portable user-carried audio-only recording device receives the audio signals. The audio signals and the position information are stored onto recording media. The present embodiment integrates the position information with the audio signals such that alteration of the position information stored on the recording media results in alteration of corresponding audio input signals stored on the recording media.

Abstract: A GPS receiver having a fast time to lock to a GPS signal by storing a time period of an incoming GPS signal in a signal memory and rapidly comparing the signal memory against locations in a replica memory having stored GPS signal replicas. The GPS receiver includes a memory-based search engine for acquiring the GPS signal so that it may be tracked. The memory-based search engine includes a signal memory for storing a millisecond of a digitized GPS signal, a replica memory section for storing replicas representative of the digitized GPS signal for all possible frequency differences between the GPS carrier frequency and a local reference frequency and phase offsets between the GPS code phase and a local reference time, and a GPS memory comparator for comparing the stored signal in signal memory to the stored replicas in replica memory and issuing an acquisition detection signal when the level of the comparison is greater than a selected threshold.

Abstract: Methods for providing a representation of location coordinates for a collection of survey points with enhanced accuracy. An obliquely oriented cylindrical surface, rather than a tangent plane, is determined and used as the projection surface at or near a survey base point, with the angular orientation and radius of the cylinder being chosen to optimize the accuracy of the projection. A scale factor that corrects for distances of locations projected onto the cylindrical surface is optionally determined and applied. A three-dimensional transformation of survey location coordinates, optimized to provide a best fit for a selected set of fiducial survey locations, is determined that provides a correspondence between a globally determined height coordinate and a locally determined elevation coordinate.

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 trip meter, such as a taximeter or a mileage meter for a commercial vehicle, such as a truck, are combined with an integral GPS receiver/computer which provides GPS position and time information. Odometer input pulses to the trip meter are accurately calibrated by using GPS position, velocity, and time information to generate corrected odometer pulses which are provided to the odometer input terminal of the trip meter. The GPS system is integrated into the trip meter for calibrating and cross checking of the input odometer pulses to provide reliable, consistent distance measurements by the trip meter. GPS position, velocity, and time information produce incontrovertibly accurate corrected, odometer input pulses and GPS time signals for the trip meter to precisely compute elapsed time and distance traveled. A backup dead-reckoning subsystem operates when the GPS receiver has service outages.

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: Method and apparatus for formation of an autocorrelation difference function of an incoming digital signal, with bit transition interval length .DELTA..tau..sub.chip, that reduces the effects of presence of a multipath signal in an incoming composite signal. First and second autocorrelation functions AC(.tau.;E;qE) and AC(.tau.;L;qL) are formed with respective first and second selected time shift values .tau.=t.sub.E and .tau.=t.sub.L, which replicate an estimate of an autocorrelation function AC(.tau.;P;qP) at an intermediate time shift value .tau.=t.sub.P that satisfies t.sub.E <t.sub.P <t.sub.L with t.sub.L -t.sub.E <2.DELTA..tau..sub.chip, and which depend upon one or more parameters qE and qL, respectively. Independently chosen, non-uniform weighting functions w1(t;qE) and w2(t;qL) are used for formation of the respective autocorrelation functions AC(.tau.;E;qE) and AC(.tau.;L;qL) that depend upon one or more parameters qE and qL.

Abstract: A blasting system using the global positioning system (GPS) for timing the detonations for a shaped blast. The blasting system includes a master station including a master GPS receiver for determining a GPS-based time and a master transceiver in communication with several charge control stations. Each charge control station includes a charge control transceiver for communicating with the master transceiver, a charge control GPS receiver for tracking the GPS-based time, and a detonator for detonating an explosive charge. In operation, the master transceiver uses the GPS-based time determined at the master station for computing detonation times and transmits these times to the charge control stations. The charge control stations then detonate the respective explosive charges when the GPS-based times determined at the charge control stations match the detonation times.

Abstract: A theodolite that includes a stand, a telescope, a friction gear and a worm gear. The telescope is pivotally secured to the stand. The clutch plate is secured to the telescope for at least limited rotational movement upon pivoting of the telescope. The friction gear is mounted for rotation about substantially the same axis as rotation of the clutch plate. The worm gear is mounted to the stand and is in constant mesh with the friction gear so that rotation of the worm gear causes rotation of the friction gear. A device engages the friction gear with the clutch plate with a frictional force. The frictional force is adjustable to allow for adjustment of the telescope separately from the worm gear.

Abstract: A system and method which enables a user platform to perform low level control of a channel unit which performs acquisition and tracking of Global Positioning System (GPS) signals processing the measurement platform which includes the channel and that performs all satellite tracking functions which are driven by interrupts. Intermediate measurements data generated therefrom, for example code phase, carrier phase and Doppler, are communicated to a user platform which computes receiver position and time. As a result, the user platform can easily be configured to perform user-specific processes without incurring conflicts with the interrupt driven processes occurring on the measurement platform. Furthermore, the user platform is configured to issue commands to the channel unit to control the operation of the measurement platform. Thus, the performance of the measurement platform can be tailored specifically to the end user application.

Abstract: A global positioning system (GPS) controlled paint spray system. The system includes a paint sprayer driver program and a GPS paint sprayer. The paint sprayer driver program enables a user of a standard drawing program using a standard personal computer to generate a print file for a drawing pattern. The GPS paint sprayer includes a GPS receiver, a geographical converter for enabling a user to convert the drawing pattern to geographical locations, a location comparator for detecting a location match between the geographical locations of the drawing pattern and a current GPS-based location, and a spray nozzle to spraying paint for matched locations.