Abstract: A method and system of synchronizing multiple tracking devices in a geo-location receiver system comprising: receiving a first plurality of geo-location signals with a first tracking device; and receiving a second plurality of geo-location signals with a second tracking device. The method also includes: enabling the first tracking device as either a master tracking device or a master-with-mark tracking device; enabling the second tracking device to operate as a slave tracking device; the master tracking device generates and transmits a timing signal to the slave tracking device; and the master-with-mark tracking device is configured to receive an external input for synchronization and generates and transmits a timing signal to the slave tracking device. The method also includes acquiring the first plurality of geo-location signals and the second plurality of geo-location signals at a substantially simultaneous instant of time.

Abstract: A method and system for determining at least one attitude angle of a rigid body. The method comprising: receiving a plurality of Global Navigation Satellite System (GNSS) satellite signals with a plurality of antennas; establishing at least one pair of antennas such that each antenna of the plurality of antennas is included in at least one antenna pair; computing single- or double-difference phases corresponding to one or more GNSS satellites for each of the pairs of antennas; and constructing a single Differential Carrier Phase Attitude (DCPA) equation based on known geometry constraints of each of the pairs of antennas. The method also includes determining a solution for the DCPA equation based on a cost function, the solution yielding at least one integer ambiguity value and the at least one attitude angle.

Abstract: A guidance system for directing a towed implement comprising: a first DGPS system, comprising an antenna located on a towing vehicle in operable communication with a receiver; a second DGPS system comprising another antenna located on a towed implement in operable communication with another receiver; a receiver configured to receive differential correctors from a reference GPS system; a controller in operable communication with the first DGPS system, the second DGPS system, and the receiver, the controller generating a first steering command; and a steering mechanism in operable communication with the controller and configured to direct a towed implement based on the first steering command provided thereto.

Abstract: A method of measuring phase of a pseudorandom (PN) sequence of chips, the method includes: generating a reference model exhibiting a reference phase, the reference phase adjustable to facilitate alignment with the phase of the pseudorandom sequence; establishing a plurality of pulsed-windows over which a plurality of samples of the pseudorandom sequence are collected for a selected accumulation interval; and accumulating the plurality of samples for each pulsed-window of the plurality of pulsed windows to form a plurality of accumulated sums. The method also includes: compensating each accumulated sum to form at least one compensated sum, if a number of level transitions and non-transitions of the pseudorandom sequence is not equal; and combining the compensated sum to determine a phase error from the plurality of compensated sums, the phase error corresponding to a phase difference between the reference phase and the phase of the pseudorandom sequence.

Abstract: A short synchronization time modem comprising a GPS receiver for receiving a broadcasted signal comprising a high precision clock. When a first short synchronization data modem communicates with a second, a PLL in each data modem synchronizes its own local clock to the same high precision clock derived from the same received broadcasted signal. The modems connect for the first time using one of many clock recovery schemes known to the modem designers. Once they disconnect, the modems keep their clocks synchronized using a local GPS receiver and the received broadcasted signal. This prevents the local clock of the modems from drifting, which significantly reduces the time period the modems need to synchronize the next time they connect.

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: A technique of accurately determining the relative position between two points, in real-time, using a single GPS receiver that makes measurements of signals transmitted from GPS satellites. A technique is applied where differential correction terms are computed as a location at an instant of time, and then applied to further times, after applying atmospheric delay adjustments, so that the position of the GPS receiver is determined accurately relative to the position at the original instant of time.