Abstract: A laser beam projecting instrument primarily for construction purposes, and preferably self-leveling, produces four or five orthogonal output beams. The high-intensity central portion of a collimated elliptical beam from a laser diode is partially diverted by a beam splitter periscope device to produce one output beam, and the remainder of that central beam region is transmitted to produce another output beam in the straight-a-head direction. Two additional beams are produced from outer portions the beam's long dimension. In another embodiment, a five-beam instrument utilized two such periscopes in succession, thus producing three beams from the high intensity central region of the collimated beam.

Abstract: A differential global positioning system (DGPS) using coarse data for the locations-in-space of GPS satellites for ranging to the GPS satellites and then determining a precise differentially corrected GPS location of a GPS user receiver. The coarse GPS data can be GPS almanac data or non-current GPS ephemeris data as long as the same data is used by both a GPS reference receiver and the GPS user receiver.

Abstract: The apparatus and method for the multipath pseudo-range error signal reduction using wide correlated optimized additional signals are disclosed. The wide correlated additional signals can be generated at different levels of the standard tracking channel to achieve the same result of minimizing the multipath signal. The additional signals are wide correlated and optimized during one-two chip periods.

Abstract: Real time kinematic (RTK) global positioning system (GPS) technology is integrated with precision farming methodologies to provide highly accurate seeding, cultivating, planting and/or harvesting operations. RTK GPS systems are used to control fully or semi-autonomous vehicles in these operations and may allow for precision planting of seeds (e.g., from a seeder equipped with an RTK GPS receiver and related equipment) and/or precision weed removal (e.g., using a vehicle fitted with weed eradication mechanisms such as augers and/or herbicide sprayers). Crop specific fertilizer/pesticide application is also enabled through the use of centimeter-level accurate positioning techniques.

Abstract: A method and system for dynamically communicating content to an occupant of a moving vehicle according to the location and direction of travel of the vehicle. Position information (such as Global Positioning System information) is used to determine the location and the direction of travel of the vehicle. The vehicle provides its location and direction of travel to a central source (e.g., a server computer system). The central source provides to the vehicle content as a function of the vehicle's location and direction of travel as well as other factors such as time of day. The central source can also provide instructions prescribing when and where content is to be displayed. Using the vehicle's position and direction of travel as well as other factors such as the time of day, a particular item of content can be selected and communicated to an occupant of the vehicle.

Abstract: A system and method that provides off-line and off-heading correction information in a convenient format that is easy for an operator to comprehend. A dual mode indication system provides two different types of navigation information in a single device presentation configuration that is efficient and effective. The dual mode indication system presents information in a manner that is intuitive with minimal sensory resource commitment. Providing the off line and off heading in simplified and effective formats assists a vehicle operator to keep a vehicle on a desired line and moving in a correct direction with minimal operator effort expended observing, interpreting and analyzing the navigation information.

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. Signals that are received from satellites are used to determine position of the integrated position and direction system. The orientation of the satellites relative to the determined position and relative to the orientation of the integrated position and direction system is then determined. In one embodiment, direction determined using the digital compass is used to determine the orientation of the satellites relative to the determined position and relative to the orientation of the integrated position and direction system. Alternatively, heading is used to determine the orientation of the satellites relative to the determined position and relative to the orientation of the integrated position and direction system.

Abstract: A method and apparatus for a guidance system that gives a farmer a choice of different approaches to coping with the problem of compaction caused by vehicular traffic are disclosed.

Abstract: Method and system for accurate vehicle navigation and tracking within a selected lane on a roadway or a waterway. A location determination (LD) receiver, carried on the vehicle, receives LD signals from satellite-based LD signal sources, receives LD signal correction information from one or more other wide area LD correction sources, estimates a corrected vehicle location (good to within 10-50 cm) and velocity (optional) relative to one or more lane boundaries that define the selected lane, and displays vehicle location and velocity within the lane. When the vehicle approaches a lane boundary too quickly, or is too close to the lane boundary, an alarm signal or other control mechanism can be activated. The LD correction information is delivered to the LD receiver via a channel of suitable bandwidth. The system can also be used to map and store lane boundary coordinates for selected segments of a roadway or waterway.

Abstract: A GPS receiver having a fast acquisition of a GPS signal having a low signal-to-noise ratio. The GPS receiver adjusts a local frequency for iteratively downconverting raw GPS signal samples to baseband GPS signal code data, combining a plurality of code epochs of the GPS signal code data in chunks and super chunks for providing representative code epochs, and correlates the representative code epochs to a replica code epoch for providing correlation times. A microcontroller processes the correlation times for providing the frequency corrections and computes a GPS pseudorange when the error in the corrected local frequency is less than a threshold. The GPS pseudoranges for several GPS satellites are transmitted back to the base for computing the GPS-based location of the GPS receiver.

Abstract: A system and method for determining when portable devices require service. In one embodiment, the system is co-located with the portable device and includes a sensor, positioning system receiver and communication transmitter. The sensor senses when the portable device requires service. The positioning system receiver receives positioning signals, such as positioning signals issued by the Global Positioning System, (GPS), and uses the positioning system signals to determine the location of the portable device. The communications transmitter transmits a service signal to a service base station to indicate that the portable device requires service. The service signal includes the determined location of the portable device, thereby eliminating the need for service personnel to physically inspect every portable device in order to determine if any portable devices require service.

Abstract: A method and system for dynamically communicating content to an occupant of 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 of the vehicle. The direction of travel of the vehicle can also be determined from the position information. Using the vehicle's position and direction of travel as well as other factors such as the time of day, a particular item of content can be selected and communicated to an occupant of the vehicle.

Abstract: A system and method for monitoring interaction between a stationary object and multiple mobile units are described. Positioning data is received from one or more mobile units. Positioning data is processed to retrieve a position of each mobile unit. Finally, one or more warning devices are activated based on a predetermined set of criteria related to the position.

Abstract: A transducer arrangement and method that generates control signals indicating relative positions of the ends of a hydraulically movable screed head. The generated control signals of the present invention are used by a conventional control circuit controlling the hydraulically movable screed head with laser receivers in a column block situation, which interrupts the reception of a laser beam from a laser transmitter by one of the laser receivers, to provide an estimated absolute position of the interrupted receiver side of the screed head until the column block situation clears. Normally, absolute measurements are available on both sides of the screed head via the laser receivers receiving the laser beam.

Abstract: A machine having a tool with hydraulically moveable ends, for example as a screed head, is setup for operation by using an inclinometer or other sensor to determine the orientation of the tool. According to this method, the on grade elevational position of the first end of the tool with respect to the reference is selected, and the first end of the tool is then moved to the desired elevational position while an elevation receiver at the first end detects the reference, such as a beam of laser light. The on grade orientation of the tool along its length from one end to the other is selected, and the second end of the tool moved until the on grade orientation of the tool along its length is sensed. The reference is then detected with the elevation receiver at the second end of the tool. The detected positions of the reference at the first and second ends of the tool are then stored as on grade positions.

Abstract: An integrated position and direction system is disclosed that includes a digital compass and a satellite positioning system (SATPOS) having a receiver adapted to receive satellite position determining signals. Direction is determined using the digital compass and heading is determined using the SATPOS. The integrated position and direction system is operable to display, on a display device, map information that is oriented according to a current orientation regardless of whether the system is stationary or moving. The map display is oriented according to either heading determined using the satellite positioning system or direction determined using the digital compass. The integrated position and direction system updates the map display to orient the map display with a current position. Moreover, the integrated position and direction system updates the map display to orient the map display with a current orientation (e.g., heading or direction).

Abstract: A method and system that provide WAAS like corrections using a server and processor on a network. For one method, satellite measurement data is collected. Satellite position error corrections are computed using the collected satellite measurement data. The computed satellite position error corrections are stored. The stored satellite position error corrections can then be later retrieved and used by a server and processor coupled to the Internet.

Abstract: A communication system having hubs and mobile units where a mobile unit uses selection signals from hubs during dedicated time slots for selecting a particular hub for communication during operational time slots. The hubs communicate on respective channels. The mobile units communicate with a particular hub on the channel associated with that hub. Each hub transmits a selection signal during a time slot that is dedicated for the selection signal from that hub. The mobile units base their selection of hub upon a comparison of the error rates of the respective selection signals and then communicate with the selected hub during with operational signals during the operational time slots. Certain message data is included in the selection signal from all the hubs in order to increase the reliability that the message data will be received by the mobile units.