Abstract: A satellite navigation system using multiple antennas for providing the position of multiple fiduciary points on an object even when fewer than four satellites are visible to some or all the antennas. Satellite signals from the multiple antennas are fed into at least one receiver. The receiver or receivers utilize constraint information, which is independent of the satellite signals. These external constraints are used to augment the signals received from the satellites, to obtain the position solution for each antenna. In a preferred embodiment, a common reference clock is used to provide an external constraint. Examples of other external constraints that can be used in the current invention are distance between the antennas, inertial measurement of attitude, rotational or linear position sensors, etc.

Abstract: A Low Earth Orbiting (LEO) satellite is used for broadcasting differential navigation corrections. Using LEO satellites, the “footprint” of the beam is much smaller than for geosynchronous satellites. Datalink bandwidth requirements are reduced to sufficiently cover an entire footprint area. With a LEO satellite transmitting in multiple beams, these footprints become even smaller. Corrections targeted to such a small area provide local area corrections broadcast from the LEO satellites. Payment, discounts, subsidies or charges are arranged to encourage different entities to own or host base stations, resulting in wide distribution of the network of base stations for use with satellite communications.

Abstract: A global navigation satellite system receiver manufacturer provides functional extensibility to a global navigation satellite system receiver. An application programming interface to the receiver is provided. The interface is public, such as using pubically available software or pubically distributed instructions, for loading on applications or other extensions to the core functionality of the GPS receiver. Other programmers than the manufacturer may add applications to the GPS receiver, avoiding separate devices in a vehicle.

Abstract: To reduce the number of processors and/or displays in mobile equipment, an operating system is emulated in one example. A primary operating system runs on a processor or uses a particular display. The emulated operating system shares the same processor and/or same display. The emulation allows use of applications drafted or written for different operating systems in a common or shared environment. As another example, a virtual terminal function is emulated on a particular device. The particular device interacts with additional sources of information for displaying images on a same display. Using emulated operating systems or virtual terminals, a navigation program is used in a vehicle. An additional program is run on the same processor or shares the same display in the same vehicle at substantially the same time.

Abstract: A Low Earth Orbiting (LEO) satellite is used for broadcasting differential navigation corrections. Using LEO satellites, the “footprint” of the beam is much smaller than for geosynchronous satellites, and therefore data link bandwidth requirements are reduced to sufficiently cover an entire area. With a LEO satellite transmitting in multiple beams, these footprints become even smaller. Corrections targeted to such a small area could have the form of local area corrections (for example, raw measurements taken from a navigation reference station) using the LEO satellites.

Abstract: A system and method for compensating for changes in relative antenna attitude in a single-receiver position detection system, such as a differential carrier phase GPS system, utilizes sensor input to detect changes in the relative attitude of at least two antennas or an antenna positioner, such as an motorized actuator or operator, that orients or re-orients the antennas to a predetermined orientation. The changes in the detected relative carrier phase due to the right hand circular polarized nature of the carrier signals are thus corrected. In this way, the high positional accuracy associated with kinematic GPS systems, for example, can be achieved even when the system's antennas are not constrained by a common rigid body, for example.

Abstract: A system and method provide for precision guiding of agricultural vehicles along a series of adjacent paths to form rows for cultivating a field. In one aspect of the invention the vehicle is moved along a first path while receiving positioning information from a navigational system (e.g., RTK GPS). This positioning information is stored in a processor and is used by the processor to compute a second path adjacent to said first path by calculating piecewise perpendicular offsets from the first path at multiple locations along the first path. The process is repeated to compute a third and subsequent paths so as to cover the field. Because of the offset process, the field may be covered with paths that have varying curvature along their length, while providing substantially no gaps or overlaps in the coverage of the field.

Abstract: A system and method provide for precision guiding of agricultural vehicles along a series of adjacent paths to form rows for cultivating a field. In one aspect of the invention the vehicle is moved along a first path while receiving positioning information from a navigational system (e.g., RTK GPS). This positioning information is stored in a processor and is used by the processor to compute a second path adjacent to said first path by calculating piecewise perpendicular offsets from the first path at multiple locations along the first path. The process is repeated to compute a third and subsequent paths so as to cover the field. Because of the offset process, the field may be covered with paths that have varying curvature along their length, while providing substantially no gaps or overlaps in the coverage of the field.

Abstract: A vehicle control system with user-guided calibration is presented. In one embodiment, a vehicle control system is presented comprising an output device and circuitry operative to provide an output, via the output device, that guides a user through a plurality of calibration steps in a particular order. The circuitry can additionally or alternatively be operative to determine which of the calibration steps, if any, to present as a next calibration step based on whether a given calibration step is successful. Other embodiments are provided, and each of the embodiments can be used alone or in combination with one another.

Abstract: A satellite navigation system using multiple antennas for providing the position of multiple fiduciary points on an object even when fewer than four satellites are visible to some or all the antennas. Satellite signals from the multiple antennas are fed into at least one receiver. The receiver or receivers utilize constraint information, which is independent of the satellite signals. These external constraints are used to augment the signals received from the satellites, to obtain the position solution for each antenna. In a preferred embodiment, a common reference clock is used to provide an external constraint. Examples of other external constraints that can be used in the current invention are distance between the antennas, inertial measurement of attitude, rotational or linear position sensors, etc.

Abstract: A satellite navigation system using multiple antennas for providing the position of multiple fiduciary points on an object even when fewer than four satellites are visible to some or all the antennas. Satellite signals from the multiple antennas are fed into at least one receiver. The receiver or receivers utilize constraint information, which is independent of the satellite signals. These external constraints are used to augment the signals received from the satellites, to obtain the position solution for each antenna. In a preferred embodiment, a common reference clock is used to provide an external constraint. Examples of other external constraints that can be used in the current invention are distance between the antennas, inertial measurement of attitude, rotational or linear position sensors, etc.

Abstract: A system including a mobile vehicle, an implement, a position sensor, a controller, a user interface (a touch-screen monitor, video monitor or keypad, as examples), a software program to compute a calibration trajectory, and a steering system for steering the vehicle to the desired or adjusted trajectory based on the error between the vehicle's desired and actual positions. In one embodiment, non-co-located sensing and control combine with a calibration procedure to help eliminate model error. Another embodiment uses co-located sensing (but not control) to calibrate the model.

Abstract: A method for adjusting a desired trajectory of an automatically guided vehicle guidance system to match a physical constraint such as an obstacle or boundary. The method works around obstacles and boundaries as they occur, consistent with the original trajectory. The method is independent of the type of vehicle. The method may be used regardless of whether the vehicle is under automatic guidance, and the method has a low computational cost.

Abstract: Described is an automatic control system for land (and possible marine) vehicles based on carrier phase differential GPS (CPGPS). The system relies on CPGPS to determine vehicle position and attitude very precisely (position to within 1 cm and attitude to within 0.1.degree.). A system incorporates a technique to calculate and compensate for antenna motion due to vehicle roll and pitch. One aspect of the system utilizes an intelligent vehicle controller that recognizes and adapts to changing conditions, such as vehicle speed, implements towed by the vehicle, soil conditions, and disturbance level. The system provides the capability to control the vehicle on various paths, including straight lines and arbitrary curves. Also described is a technique for initialization and vehicle control using only a single pseudolite.