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 hybrid positioning system for locating an object using a combination of a GPS pseudoranges and local radio pseudoranges. The system includes one or more receptors coupled to a base station, and one or more location markers. The location markers are located with an object whose location is to be determined. Each of the location markers includes a GPS receiver for determining GPS pseudoranges and a radio transmitter for transmitting a radio signal including the GPS pseudoranges and information about the object. Each of the receptors passes the radio signal to the base station as an interface signal. The base station includes a radio pseudorange detector, a base GPS receiver, and a hybrid pseudorange processor. The radio pseudorange detector uses the times-of-arrival of the interface signals and the known interface signal transit times for determining radio pseudoranges from the location marker to the receptors. The base GPS receiver determines the locations-in-space of GPS satellites.

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: A method and system for generating and maintaining a database comprising a location-sensitive timetable. At multiple locations, a device (e.g., an integrated position and direction system) listens for broadcast signals from broadcasting devices (e.g., Global Positioning System satellites). For each location, the device records the time and date and the number of satellites from which a signal is received. The device can also record the identities of satellites that can and cannot be picked up. The information recorded by the device can be used to automatically generate a timetable showing the dates and times of day for each location that are and are not satisfactory for doing data maintenance, based on the number of satellites available for viewing. The recorded information can also be used to automatically predict future dates and times for each location that will or will not be satisfactory for data maintenance.

Abstract: A GPS weather data recording system for use with the dispensing of chemicals to agriculture fields. A GPS receiver is used to determine a series of positions of a vehicle and the velocity of the vehicle as the vehicle traverses an agricultural field. The series of positions and velocity trace the vehicle's ground track across the agricultural field. A wind sensor is used to measure wind velocity with respect to the vehicle. A data storage system is used for storing data measurements, such as the series of positions from the GPS receiver and a series of corresponding wind measurements from the wind sensor. A computer system is coupled to the data storage system. The computer system receives the series of vehicle positions and velocity from the GPS receiver and receives wind velocity measurements from the wind sensor.

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 finding an intended destination using an in-vehicle navigation system. Intended destinations are received and are coupled to an in-vehicle navigation system using various methods. In one embodiment, the intended destinations are stored on a magnetic strip that is disposed on the back of a plastic card. The plastic card is inserted into the in-vehicle navigation system where the data on the magnetic strip is read. Alternatively, a transmitter/receiver system is used to transmit the intended destinations to the in-vehicle navigation system. Once the intended destinations are coupled to the in-vehicle navigation system, the user is able to find an intended destination by selecting the desired intended destination from a list displayed by the in-vehicle navigation system. The in-vehicle navigation system then determines the current location of the vehicle and indicates how to find the intended destination using a moving map display and/or verbal instructions.

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 (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. At a first location, the integrated position and direction system is oriented to the offset feature and is operated to determine a first set of measurements relative to the offset feature using the digital compass and the satellite positioning system. At a second location, the integrated position and direction system is oriented to the offset feature and is operated to determine a second set of measurements relative to the offset feature using the digital compass and the satellite positioning system. The integrated position and direction system calculates the position of the offset feature using the first and second sets of measurements.

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 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 system and method for automated differential correction processing of field data in a global positioning system (GPS). In one embodiment, the present invention retrieves GPS field data collected by one or more GPS receivers from a storage device, and then automatically selects the most appropriate differential correction scheme to generate a solution without user intervention. More specifically, the present invention executes a code-based correction scheme to generate a code-based solution for the field data. Next, the present invention examines the field data to determine whether a carrier phase correction is applicable. If the field data supports carrier phase correction, the present invention generates a carrier phase solution, compares it with the code-based solution, and returns the more accurate of the two solutions as the final result. If the field data does not support a carrier phase correction, the present invention returns the code-based solution as the final result.

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 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: In one embodiment, the present invention includes a vehicle guidance system. In one embodiment, the vehicle guidance system includes a navigation system capable of providing vehicle location information including the vehicle position. In the present embodiment, the vehicle guidance system further includes data storage means capable of storing at least one pre-determined course having a preferred direction of travel. The present embodiment also includes processing means capable of receiving the vehicle location information, calculating the magnitude of any displacement of the vehicle in a direction perpendicular to the closest point of the predetermined course and thereupon generating an intermediate waypoint at a predetermined response distance from the vehicle.

Abstract: A control system for a GPS receiver 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. Distribution of the settings over the range of a slide bar control need not be linear. Preferably, each set of the configuration parameters includes a setting for a PDOP mask, a signal to noise ratio mask, an elevation mask and a minimum number of satellites to be used by the receiver in making a position computation.

Abstract: A DGPS system using GPS almanac data for determining the locations-in-space and the DGPS corrections for GPS satellites for providing a differentially corrected location of a remote GPS user receiver. A GPS reference receiver determines almanac-based DGPS corrections from the differences between ranges that are measured to GPS satellites and ranges that are calculated to the GPS almanac-based locations-in-space of the GPS satellites from the known location of the GPS reference receiver. The GPS user receiver measures pseudoranges to the GPS satellites. Then, in a first embodiment, the GPS reference receiver radios the DGPS corrections to the GPS user receiver. The GPS user receiver uses almanac-based locations-in-space for the GPS satellites and the almanac-based DGPS corrections for differentially correcting the measured user pseudoranges for providing a differentially corrected user location. In a second embodiment, the GPS user receiver radios the measured user pseudoranges to the GPS reference receiver.

Abstract: A system for improving the accuracy of location coordinate determined in a survey of a chosen region. A grid of spaced apart points is imposed on the region, and a set of survey control points is provided. A “near set” of nearest survey control points is associated with each grid point, and the number of elements in this new set may vary with the grid point. Definition of a near set can vary from one grid point to the next. For each grid point, a transformation T from a first coordinate system to a second coordinate system is determined that minimizes a collective difference between coordinates of each survey control point in the near set and the corresponding coordinates of that survey control point under the transformation T. For one, two or three coordinates of each grid point, the difference(s) between the coordinate(s) of the grid point in the near set and the corresponding coordinate(s) of that grid point under the transformation T are computed.