Abstract: A complex and intricate GNSS antenna that is created using inexpensive manufacturing techniques is disclosed. The antenna combines a loop antenna and a cross dipole antenna together, in a single plane, to create an optimal GNSS gain pattern. The antenna structure is symmetric and right-hand circular polarized to force correct polarization over a wide range of frequency and beamwidth. The feed structure is part of the antenna radiating element.

Abstract: A complex and intricate GNSS antenna that is created using inexpensive manufacturing techniques is disclosed. The antenna combines a loop antenna and a cross dipole antenna together, in a single plane, to create an optimal GNSS gain pattern. The antenna structure is symmetric and right-hand circular polarized to force correct polarization over a wide range of frequency and beamwidth. The feed structure is part of the antenna radiating element.

Abstract: An integrated machine guidance system for guiding a critical device of a machine includes global navigation satellite system (GNSS) antennas, a GNSS receiver, a guidance controller, and a wireless communication system enclosed in a housing. The guidance controller is adapted to compute an actual position of the critical device and determine a direction that the critical device should move to arrive at a desired position. The housing may be coupled to a mounting element, which is attached to the critical device. A display unit is in communication with the guidance controller, and is coupled to the housing so that it is visible to an operator in the cab of the machine. The guidance controller may communicate with another display unit located remote from the housing via the wireless communication system. Each of the display units can provide an indication of the direction that the critical device should move.

Abstract: An antenna is provided for GNSS and other applications and includes an adjustable-height vertical support PCB mounted on a ground plane and mounting a crossed-dipole radiating arm element assembly. The gain pattern of the antenna can be varied by constructing the vertical support PCB with different heights or adjusting the height and gain pattern in the field. Vehicles with significant pitch and roll can be provided with low-horizon tracking capability by providing a high-profile antenna configuration. Alternatively, low-profile configurations provide steeper gain pattern rolloff at the horizon for maximal multipath rejection and high accuracy. The droop angles of the radiating arm elements are also adjustable for varying the gain pattern and beamwidth. A matching and phasing network is connected to the radiating arm elements and provides a relatively constant input impedance for the various antenna configurations.

Abstract: An antenna is provided for GNSS and other applications and includes an adjustable-height vertical support PCB mounted on a ground plane and mounting a crossed-dipole radiating arm element assembly. The gain pattern of the antenna can be varied by constructing the vertical support PCB with different heights or adjusting the height and gain pattern in the field. Vehicles with significant pitch and roll can be provided with low-horizon tracking capability by providing a high-profile antenna configuration. Alternatively, low-profile configurations provide steeper gain pattern rolloff at the horizon for maximal multipath rejection and high accuracy. The droop angles of the radiating arm elements are also adjustable for varying the gain pattern and beamwidth. A matching and phasing network is connected to the radiating arm elements and provides a relatively constant input impedance for the various antenna configurations.

Abstract: A sensor system for vehicle steering control comprising: a plurality of global navigation satellite sensor systems (GNSS) including receivers and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase corrected real time kinematic (RTK) position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system.

Abstract: A system for ascertaining the range from an interrogator to one or more transponders comprises an interrogator that transmits an RF carrier that is received by each transponder, the energy in the received carrier being used to charge up a storage capacitor in each senses the termination of the received carrier and initiates a known delay interval different from those of the other transponders. At the end of the delay interval, the transponder transmits an RF signal which is received by the interrogator. The interrogator then calculates the range to the transponder by subtracting the known delay interval from the round trip time registered in the timer.

Abstract: A receiver for position-determining ranging signals transmitted by earth-orbiting satellites uses a set of accumulators, each of which accumulates signal samples corresponding with a position along the rising edges of incoming PRN pulses. An MMT processor calculates the rising edges of the direct path component of the received signal, selects the accumulator whose content correspond to a reference value related to the pulse height of the direct path component and compares the timing of the samples in that accumulator with the timing of the reference value on a reference pulse.

Abstract: Apparatus and process for determining the position and heading or attitude of an antenna array are described based on radiating sources, preferably GNSS or other such satellite positioning systems. An optimum satellite is selected and the antenna array is “null steered” by combining the phase of the received signals to calculate a null or null angle that points toward the optimum satellite. The null will determine angle for elevation toward the optimum satellite and azimuth or heading. The heading is the azimuth of the (which may be actual or calculated) projection of the null vector to the satellite onto the Earth's surface. The actual location on Earth of the antenna array can be found and the antenna array azimuth with respect to the satellite can be determined. The null angle may be measured more precisely by dithering on either side to average out noise and then averaging the angle deviations to calculate the null angle.

Abstract: A method for measuring relative position of fixed or slow-moving points in close proximity comprising: receiving a set of satellite signals with a first receiver corresponding to a first position; receiving a related set of satellite signals with a second receiver corresponding to a second position; and computing a position of the second position based on at least one of code phase and carrier phase differencing techniques. At least one of: a clock used in the first receiver and a clock used in the second receiver are synchronized to eliminate clock variation between the first receiver and the second receiver; and the first receiver and the second receiver share a common clock.

Abstract: A technique of accurately determining the relative position between two points using carrier phase information from receivers capable of making code and carrier phase measurements on signals transmitted from GPS satellites as well as signals transmitted from WAAS, EGNOS, MSAS or other Wide Area Augmentation System satellites (hereafter referred to simply as WAAS satellites). These signals are processed by a receiving system to determine relative position, for the purpose of surveying or otherwise, with the accuracy of carrier phase measurements being obtained. Signal processing similar to that used in existing GPS carrier phase based relative positioning receivers is used with WAAS signals as well. Benefits include faster and more reliable integer ambiguity resolution, protection from cycle slips and loss of sufficient satellites, and possibility of extending the operating range by allowing increased separation of reference and base receivers by incorporating ionospheric models provided by WAAS.

Abstract: An antenna assembly comprises a dome-like substrate with a ground plane layer on the interior surface of the substrate and a radiative patch on the outer surface of the substrate. The cavity defined by the substrate is closed off by a base having a conductive layer that is connected to the ground plane layer, thereby to isolate the cavity and circuit elements that may be disposed therein. Preferably the substrate has a polyhedral form and the radiative patch is a polygon having apex portions that extend down over the side surface of the substrate to enhance the sensitivity of the antenna at low elevations.