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: The integrated laser and satellite positional system receiver is disclosed. The integrated laser and satellite positioning system receiver can provide a plurality of mobile units with a laser plane data determined with a millimeter relative accuracy. The integrated laser and differential satellite positioning system receiver can also generate and transmit the differential correctional data to a plurality of mobile units. Each mobile unit equipped with a mobile satellite positioning system receiver can use the differential correction data and the high precision laser plane data to improve its position determination capabilities.

Abstract: A control system for a combined GPS receiver and pseudolite receiver that allows adjustment of a number of data collection (i.e., configuration) parameters for the receiver. Preferably, a single interface allows for setting multiple parameters at the same time. Setting the configuration parameters may be in response to a user input specifying a desired quality of position estimate to be provided by the receiver and may be accomplished using a slide bar control. The slide bar control may be a graphical representation displayed to the user and may allow the user to choose from a number of predetermined settings, each corresponding to a set of different configuration parameters for the receiver.

Abstract: A system and method which separates time critical interrupt driven processing of Global Positioning System (GPS) signals from non-time critical processing. A measurement platform 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.

Abstract: The apparatus and method for estimation and minimization of the residual multipath error signal are disclosed. The reduction of the multipath error signal is achieved by using the weighted or modified tracking. The estimation and minimization of the reduced multipath error signals is achieved by using the generator of additional modified or weighted signals.

Abstract: A task description is stored in a database accessible by a mobile computer system. The mobile computer system receives positioning information corresponding to its geographic location and indexes the database based on the positioning information when the information indicates that the mobile computer system is in a geographic location that facilitates completion of a task associated with the task description. The database may be resident in the mobile computer system or accessible in other ways, for example, via the Internet. The task description preferably includes a geocode which corresponds to the geographic location at which completion of the task may be facilitated. The task description may also include textual, voice or other message which can be displayed and/or played back to a user. The positioning information may be obtained from a GPS satellite, a GLONASS satellite or a pseudolite. The mobile computer system may be a portable unit, such as a PDA, or integrated within a vehicle.

Abstract: The apparatus and method of the present invention is designed to receive SATPS satellites encoded information using a high gain antenna and pre-process the encoded information. The apparatus includes a High Gain Antenna (HGA), an extracting receiver, and a transmitter circuit configured to transmit the unknown code modulated on a transmission frequency for further processing in the delayed correlation receiver.

Abstract: A system and method for selecting at least one target with strong reflectivity from a set of strong and weak reflectors by using an amplitude of a reflected signal to make such a selection. The pre-computed look-up table that relates an amplitude of the reflected signal from a target with a strong reflectivity to the distance at which such target is located is used in a real-time mode to separate weak reflectors from strong reflectors. In the post-processing mode the usage of normalizing function allows to further differentiate between strong reflectors (like windows) and very strong reflectors (like prisms).

Abstract: A three dimensional laser tracking and control system is disclosed. The system includes a laser beacon generating a three dimensional rotating and scanning laser beam that covers a three-dimensional area. Each mobile unit has identification number (ID) and is equipped with a intelligent reflector (IR). Each mobile unit uses its intelligent reflector (IR) to communicate to the signal system its ID and the time of illumination by the laser beam. The signal system calculates the three dimensional coordinates for each mobile unit and communicates the positional data back to each mobile unit using the same laser beam during the subsequent rotation cycles.

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: 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: The method of supplementing the satellite data by the satellite-calibrated baro data when the receiver autonomous integrity monitoring function (RAIM) is unavailable and when the horizontal protection level (HPL) does not satisfy the horizontal alert limit (HAL) requirement is disclosed. The baro data is adjusted to compensate for the lack of baro calibration in the position solution domain. The HPL is re-computed using the satellite-calibrated adjusted baro data. The re-computed HPL could satisfy the HAL requirement which would make the RAIM function available when it would be otherwise unavailable.

Abstract: Method and system for determining a position of a platform using a set of range measurements between the platform and a set of known positions that avoids the frequent recalculation of square-roots in range predictions. The platform state estimate is updated by substituting the difference between the square of the range measurement and the square of the distance from the assumed position of the platform to the known position to which the range measurement corresponds scaled by the inverse twice distance between the predicted position of the platform and the known position, for each of the measurement residuals. The predicted state of the platform is updated until the platform state converges on a limit to a desired accuracy.

Abstract: The present invention discloses the apparatus and the method for calibrating a Narrow Band Receiver in real time for code group delay errors in the signals transmitted by a Narrow Band Transmitter. The apparatus includes a Calibration circuit used to generate a calibration signal that is substantially free from code delay errors, and that is substantially similar to the signal emanating from the Narrow band Transmitter. The calibration signal can be used by the Narrow Band receiver to measure and offset the group delay errors in real time.

Abstract: A method and apparatus for calibrating sensors of a tool positioning mechanism on a mobile machine are provided. The mobile machine includes a tool, a tool positioning mechanism having a plurality of sensors for providing signals indicative of the physical configuration of the mechanism, a satellite positioning system, and a plurality of positioning system antennas. One of the antennas is detachably mounted on the tool while an other antenna is mounted to a location on the machine other than on the tool. With the positioning mechanism configured so that the tool is at its maximum height, the satellite positioning system is operated to acquire real-time kinematic (RTK) data from the antennas and to process the RTK data to precisely determine the position of the tool. The sensors are then calibrated based on the precisely determined position of the tool.

Abstract: Methods and systems for resolving the lock point ambiguity for the GPS receiver are disclosed. The method involves generation of the absolute lock point data bit by the reference station receiver, transmission of the absolute data bit to the rover receiver, and comparison between the raw lock point data with the absolute lock point data bit in the rover receiver. The system employs the reference station receiver, the rover receiver, and the communication link.

Abstract: The method of supplementing the satellite data by the satellite-calibrated baro data when the receiver autonomous integrity monitoring function (RAIM) is unavailable and when the horizontal protection level (HPL) does not satisfy the horizontal alert limit (HAL) requirement is disclosed. The baro data is calibrated with satellite data if maximum weighted vertical dilution of precision with one satellite removed at one time (max {SubWVDOP}) is less than a predetermined threshold (TSUB) and if a test statistic is less than a predetermined test statistic threshold (TST). The HPL is re-computed using the satellite-calibrated baro data. The re-computed HPL could satisfy the HAL requirement which would make the RAIM function available when it would be otherwise unavailable.

Abstract: A three dimensional laser tracking and control system is disclosed. The system includes a laser beacon generating a three dimensional rotating and scanning laser beam that covers a three-dimensional area. Each mobile unit has identification number (ID) and is equipped with a intelligent reflector (IR). Each mobile unit uses its intelligent reflector (IR) to communicate to the signal system its ID and the time of illumination by the laser beam. The signal system calculates the three dimensional coordinates for each mobile unit and communicates the positional data back to each mobile unit using the same laser beam during the subsequent rotation cycles.

Abstract: A method for fast acquisition, in as little as 6-15 seconds, of signals from a satellite in a Satellite Positioning System (SATPS), such as GPS or GLONASS, that does not require permanent storage of satellite ephemeris information at an SATPS ground station. This SATPS signal acquisition method can be used whenever the “new” station initially powers up or has lost lock on one or more SATPS signals that must be (re)acquired. A reference SATPS station provides the new SATPS station with an estimated reference station location and ephemeris information for one or more identified SATPS satellites visible from the reference station. The new station receives and uses this information to establish carrier frequency ranges to search for the identified SATPS satellite, by limiting the search to a reduced frequency range based upon estimated Doppler shift of SATPS signals received from this satellite.