Abstract: A multi-stage process for detecting and excluding faulty measurements in a satellite positioning system receiver are described. Availability of fault detection is evaluated based on satellite geometry and satellite measurement quality. If fault detection is unavailable using only satellite measurements, an additional measurement is used, and fault detection availability is again evaluated. If fault detection is available, detection of a potential fault is performed. If a fault is detected, an exclusion/isolation process is activated. In that case, a fault exclusion operation is tested for availability. If fault exclusion is unavailable using only satellite measurements, an additional measurement is incorporated, and fault exclusion availability is again evaluated. If fault exclusion is available, an attempt is made to isolate and exclude the faulty measurement from a list of satellite measurements used for the navigation solution.

Abstract: A method and apparatus for coupling data from a base station to a rover unit for determining the position of the rover unit. Multiple radio channels are monitored by the base station and a radio channel is assigned that is unoccupied. A RTK message is then transmitted by the base station that includes the assigned radio channel. The rover unit then monitors the assigned radio channel for the next RTK message. The assigned radio channel is periodically updated. Each following RTK message is transmitted over a previously assigned radio channel. This results in both the base station and the rover unit “hopping” from channel to channel for communicating the RTK message from the base station to the rover unit. The rover unit uses the received RTK message, along with signals from a position determination system, for determining position.

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, and with the wireless Internet data accesses devices (WIDAD). 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 PBS wirelessly downloads its logged set of data into the Internet server using the (PBS-WIDAD). The SBS determines its precise position coordinates by accessing wirelessly the PBS logged data on the Internet server using the (SBS-WIDAD).

Abstract: The satellite navigational system integrated with the tilt measurement system capable of precise measurement of the actual coordinates of the mobile unit that moves along a track with variable tilt is disclosed. Using the integrated satellite/tilt measurement system, a plurality of 3 dimensional lines separated by optimal swathing offset vector can be formed and followed in order to provide field guidance during a precision farming operation across variably inclined terrain.

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: A method and apparatus for determining position using a handheld personal computer. A cradle is disclosed that that is adapted to couple to a handheld personal computer. In one embodiment, the cradle includes projecting members that capture the handheld personal computer and hold it securely in place. The cradle includes a position determining system that is adapted to determine position. Upon coupling the cradle to a handheld personal computer, the cradle is operable to determine position. Once position is determined, the determined position is displayed on the display of the handheld personal computer. The display can include a display of a moving map and an icon indicating the current position relative to the map. All required hardware and software for storing the map database and for determining position are included within the cradle.

Abstract: A method and system thereof for processing data in real time or post-processing, such as Global Positioning System (GPS) data that have been formatted in the National Marine Electronics Association (NMEA) format. In the GPS embodiment, uncorrected GPS data indicating an estimated position are computed by a receiver via signals from a first broadcaster (e.g., GPS satellites). Differential GPS (DGPS) data are received by the receiver via a signal from a second broadcaster (e.g., a GPS base station). A message is generated by the receiver when the signal from the second broadcaster is not received. The message contains information sufficient to identify the DGPS data stored by the second broadcaster needed to correct the uncorrected GPS data. The message and the uncorrected GPS data are stored by the receiver for subsequent processing. The DGPS data are retrieved from the second broadcaster, and the message is used to identify the DGPS data required to correct the uncorrected information.

Abstract: A communication system using GPS-based time for synchronizing communication data packets and symbols. The communication system includes a transmit apparatus for transmitting and a receive apparatus for receiving a communication data signal. The transmit apparatus includes a transmit station GPS receiver for providing GPS-based time, a transmit framer for using the GPS-based time for framing packets of communication data symbols, and a transmit symbol timer for synchronizing the communication data symbols to the GPS-based time. The receive apparatus includes a GPS receiver for providing the GPS-based time, a receive framer for using the GPS-based time for receiving the packets of the communication data signal, and a receive symbol timer for synchronizing the reception of the communication data symbols to the GPS-based time.

Abstract: A position identification system, that employs satellite navigational or similar positioning technology is provided. In one embodiment, the position identification system includes a receiver for receiving position signals from a positioning system; an orientation device that is configured to rotate about at least one axis; a pointing element coupled to the orientation device to provide indication of a direction to a desired position; and a processor that is coupled to the receiver to receive the position signals. The processor computes a current position of the position identification system based upon the position signals. The processor directs the orientation device, based upon the current position and the desired position, with the pointing device tracking the direction to the desired position as the current position changes. Using the positioning system, a pointing device is used to identify the direction to the desired location to the user of the positioning system.

Abstract: A network of non-cooperative integrated pseudolite (PL)/satellite base station (SBS) transmitters covering an open area. The network comprises a first plurality (K) of integrated pseudolite/satellite base station (PL)1/(SBS) transmitters, located in an open area A, and a second plurality (M) of non-cooperative integrated PL2/SBS transmitters, located in an open area B. K and M are integers. Each PL transmitter is co-located with one SBS. Each SBS provides a satellite timing synchronization signal. Each integrated active (transmitting) PL/SBS transmitter transmits its position location as a part of its message. The first plurality (K) of integrated PL1/SBS transmitters includes a substantially sufficient number of active integrated PL1/SBS transmitters in order to fill out satellite shades of coverage and to substantially cover the area A. Each integrated PL2/SBS transmitter continuously detects a plurality of ranging signals transmitted by each active integrated PL1/SBS transmitter.

Abstract: An integrated split-spectrum pseudolite/satellite base station (SS-PL)/SBS transmitter comprising a satellite base station and a split-spectrum pseudolite (SS-PL) transmitter co-located with the satellite base station. The satellite base station provides a timing synchronization signal. The satellite base station also provides a self-surveying capability for the split-spectrum pseudolite (SS-PL). The split-spectrum pseudolite (SS-PL) generates a split-spectrum sideband signal that minimizes interference with the reception of at least one satellite signal by the satellite base station.

Abstract: An apparatus and method for controlling a hydraulically movable tool carried by a machine in order to maintain a selected horizontal orientation and a selected elevation relative to an external light reference. The apparatus is a control device, having a light detector, placed at a known location along a longitudinal axis of the tool and a single-axis gravity-based sensor. The gravity-based sensor is also provided within the housing of the control device to measure the horizontal orientation (side-to-side slope or pitch) of the longitudinal axis of the tool relative to true horizontal at the known location. Finally, with internal valve drivers, the control device individually controls the lift mechanism(s) of the hydraulically movable tool to maintain both a selected elevation and a selected horizontal orientation with only the signals provided by the light detector and the gravity-based sensor.

Abstract: A cordless machine operation detector including a vibration sensor, a location detector, a data logger, and a transceiver. The vibration sensor detects when a machine is operating by sensing the vibrations that are caused by the machine during operation. The location detector provides a geographical location and includes a time clock for providing time. The data logger uses time from the time clock and an operation indication from the vibration sensor for logging the time for operation of the machine. The data logger also logs a geographical location associated with the machine operation. The transceiver communicates the times and locations of the operation of the machine through an interchange to a tracking monitor. The machine operation detector, the interchange, or the tracking monitor includes an engine time monitor and an alarm sensor. The engine time monitor tracks an accumulated time of operation of the machine.

Abstract: A first form line is defined using two or more terrestrial locations. The first form line may be predefined or may be defined by user during a spraying operation. A second form line is then computed using positioning data obtained while following the first form line and a swathing offset corresponding to the width of a spray pattern. The second form line is updated according to one or more deviations from the computed path. The deviations may correspond to operator inputted corrections which allow for obstacle avoidance, etc. The updating generally occurs by following the second form line as defined by the positioning data and the swathing offset and then deviating from the second form line to accommodate one or more terrain features. New GPS data is collected during these steps of following and deviating from the second form line and new positions are computed from the new GPS data. Finally, the updated second form line is defined using the new positions computed from the new GPS data.

Abstract: A satellite positioning-based guidance system and method that utilize a simulated inertial navigation system are disclosed. The trajectory of the body of a non-thrusted flight vehicle is used instead of a conventional inertial navigation system. The attitude of the flight vehicle is determined using a satellite receiver, and the Extended Kalman filter is used to implement the navigation function.

Abstract: An arrangement is provided for determining the relative angular orientation between an excavator bucket and the dipper stick of an excavator. The excavator bucket is mounted on a bucket linkage that is pivotally secured to the end of the dipper stick. An hydraulic actuator has an hydraulic cylinder pivotally connected to the dipper stick, and a piston rod pivotally connected to the bucket linkage. Extension or contraction of the hydraulic actuator causes the excavator bucket to be pivoted by the bucket linkage with respect to the dipper stick. A cable extension linear position transducer having a transducer casing, a sheath extending from the casing to a pulley system, and an extensible belt cable extending from the sheath through the pulley system to an end of the piston rod, provides an electrical output related to the extension of the belt cable from the sheath. A transducer mounting secures the casing of the cable extension linear position transducer in fixed relationship to the hydraulic cylinder.

Abstract: An integrated position and direction system and method thereof for determining drift. The integrated position and direction system comprises a satellite positioning system and a digital compass. The satellite positioning system is used for determining position and heading, and the digital compass is used for determining direction. An amount of drift can be determined using the heading and the direction. Knowing the amount of drift, a course compensating for the drift can be determined. Thus, a craft that has drifted from its planned course can be directed to a course that will allow it to reach its intended destination.