Abstract: An integrated position determination system and communication system is disclosed that includes an antenna and that includes position signal processing circuitry for determining position. The integrated position determination system and communication system also includes a radio for communicating with other position determination systems that is coupled to the position signal processing circuitry and a power supply. The integrated position determination system and communication system also includes a range pole to which the other components of the integrated position determination system and communication system are attached. The components of the integrated position determination system and communication system are located such that the system is both horizontally balanced and vertically balanced. More particularly, the integrated position determination system and communication system is horizontally balanced about the centerline of the range pole and is vertically balanced about a carrying point.

Abstract: A combined satellite positioning and electro-optical total station system includes a reference oscillator that provides local oscillator signals for a satellite navigation receiver and a precision frequency source for use by an electronic distance meter. When the satellite navigation receiver is locked onto and tracking orbiting navigation satellites, the highly precise cesium-rubidium clocks in the navigation satellite system can be used as standards to control the reference oscillator in the combined satellite positioning and electro-optical total station system. Baseline measurements made by the electronic distance meter are therefore not subject to mis-calibrations and drift as long as the satellite navigation receiver is locked onto and tracking the orbiting navigation satellites.

Abstract: A method of generating a noise estimate during seismic surveying, including measuring noise energy having a plurality of frequencies in a second time interval. The second time interval having a second start time delayed from a first start time of a first time interval during which a first plurality of reflected seismic signals are present. The plurality of reflected seismic signals having the plurality of frequencies. The second time interval approximately concurrent with the first time interval to measure one of the plurality of frequencies of the noise energy different than one of the plurality of frequencies of the first plurality of reflected seismic signals that are present. A noise estimate is generated based on the noise energy measured.

Abstract: A method and apparatus for testing components is disclosed. The method involves a system operating to collect data in a certain frequency range, and utilizing signals outside that frequency range to test the system during operation. Such testing may be conducted on a not-to-interfere basis, thereby allowing for testing during operation of systems in continuous use.

Abstract: A pseudolite for transmitting a global positioning system (GPS) signal having identification information for a GPS satellite that is currently out-of-view. The pseudolite mimics a global positioning system (GPS) signal by using a C/A pseudorandom (PRN) identification code for a GPS satellite that is allocated in the GPS system but is unreceivable in the local vicinity and location-determination information including ephemeris data corresponding to the geographical location of the pseudolite. In order to ensure that two of the GPS pseudolites in the same vicinity do not use the identification PRN code from the same out-of-view GPS satellite, the pseudolite listens first before transmitting to detect the identifications in the received GPS signals.

Abstract: A method for determining a scale factor of an accelerometer. The scale factor is used to precisely convert the electrical output of the accelerometer into units of acceleration. The accelerometer to be calibrated is mounted on a turntable mechanism. The turntable is configured so that the axis of rotation of the turntable is tilted with respect to the local gravity vector. The turntable is then spun around the axis of rotation at an angular velocity, such that the accelerometer experiences a time varying component of the local gravity vector. The output of the accelerometer is logged as the accelerometer experiences the time varying component of the local gravity vector. The logged output of the accelerometer is compared to a predicted output of the accelerometer, wherein the predicted output is based on the tilt angle of the turntable and the angular velocity of the turntable and on the value of gravitational acceleration at the location of calibration.

Abstract: Field-deployable spatial positioning or measurement systems are provided for improved versatility, reliability and performance. The spatial positioning or measurement systems use rotating laser fans or beams for positioning and measuring and include a system integrated field-deployable length standard that uses a reelable tape with positional indents. The systems further include the use of labyrinth seals at interface volumes between rotating laser heads and transmitter assemblies to prevent ingress of contaminants and allow for elimination of the use of rotary seals. Further, new dynamic leveling techniques are provided to plumb positional laser transmitter systems. Still further, strobe beam configurations are provided for improved near/far performance and a vertical mode sensing scheme that allows switching to measuring tall structures when needed.

Abstract: The transmitter for projecting a beam of laser light includes a source of a beam of laser light, and a projection arrangement for directing the beam of laser light at a selected grade. The transmitter further includes a temperature sensor for detecting the temperature of said transmitter, and a temperature correction circuit, including a look-up table, responsive to said temperature sensor, for adjusting said projection arrangement in dependence upon offset grade values that are stored in said look-up table for a plurality of transmitter temperature ranges. These offset grade values are separately determined on an empirical basis for each transmitter, such that temperature induced errors in the direction of the beam of laser light are compensated.

Abstract: The present invention provides a method and apparatus configured to provide graphical symbols indicative of a separation value between a first and second location, measured from a predetermined reference point. In one embodiment, the separation value relates to at least one of the direct distance between said first and second locations and the angle subtended between said first and second location at the said predetermined reference point. In one embodiment, the separation value may be resolved into mutually orthogonal components. An alpha-numeric display may also be included and configured to represent the magnitude of said separation values.

Abstract: The transmitter for projecting a beam of laser light includes a source of a beam of laser light, and a projection arrangement for directing the beam of laser light at a selected grade. The transmitter further includes a temperature sensor for detecting the temperature of said transmitter, and a temperature correction circuit, including a look-up table, responsive to said temperature sensor, for adjusting said projection arrangement in dependence upon offset grade values that are stored in said look-up table for a plurality of transmitter temperatures. These offset grade values are separately determined on an empirical basis for each transmitter, such that temperatures induced errors in the direction of the beam of laser light are compensated.

Abstract: A system and method of graphical display of survey information in which input survey data is classified as important or less important and the graphical display shows the important data as a point and a solid vector, and the less important data as a point and a stub-vector, such that the display of the less important data does not significantly obscure the display of the important data.

Abstract: A combined satellite positioning and electro-optical total station system includes a reference oscillator that provides local oscillator signals for a satellite navigation receiver and a precision frequency source for use by an electronic distance meter. When the satellite navigation receiver is locked onto and tracking orbiting navigation satellites, the highly precise cesium-rubidium clocks in the navigation satellite system can be used as standards to control the reference oscillator in the combined satellite positioning and electro-optical total station system. Baseline measurements made by the electronic distance meter are therefore not subject to mis-calibrations and drift as long as the satellite navigation receiver is locked onto and tracking the orbiting navigation satellites.

Abstract: A vehicle fleet management information system identifies location and direction of movement of each vehicle in a fleet in real-time, and automatically reports such information, as well as status of predetermined events in which the vehicle is engaged, directly to the fleet manager. Each fleet vehicle has an assigned time slot to transmit its reporting information over a communications network without interfering with transmissions from other vehicles in their own respective time slots. A timing control phase lock loop (PLL) provides precise time synchronization for timing corrections from a global positioning system (GPS) based time reference. A dual band full-duplex interface of the network has TDMA on one-half and broadcast on the other half. Microprocessor time processing units in components of the network perform precise clock synchronization. Space diversity performed on received vehicle transmitted messages avoids data corruption.

Abstract: A method and apparatus for a guidance system that gives a farmer a choice of different approaches to coping with the problem of compaction caused by vehicular traffic are disclosed.

Abstract: The present invention provides a radio navigation emulating GPS device. In one embodiment, the radio navigation emulating GPS device receives an identifier associated with a conventional radio navaid. The present radio navigation emulating GPS device then retrieves latitude and longitude information corresponding to the received conventional radio navaid from a database. A satellite based position information system generates position information for the aircraft on which the present radio navigation emulating GPS device is disposed. The present radio navigation emulating GPS device then generates navigation information for the aircraft using the retrieved latitude and longitude information and the satellite based position information for the aircraft. The present radio navigation emulating GPS device then presents the navigation information in a manner which emulates the presentation of navigation information generated by a conventional radio navigation device.

Abstract: An integrated position and direction system is disclosed that includes a digital compass, a communication module, and a satellite positioning system having a receiver adapted to receive satellite position determining signals. Signals that are received from satellites are used to determine position of the integrated position and direction system. A method for updating data is disclosed in which the integrated position and direction system communicates with a remote site and sends a determined position to the remote site. A response is generated and is transmitted to the integrated position and direction system that includes data relating to features located near the determined position. The received data is used to generate a display that indicates the position and the orientation of the features relative to the integrated position and direction system.

Abstract: A method and apparatus for determining position using a handheld personal computer. A cradle is disclosed that that is adapted to couple to a handheld personal computer. In one embodiment, the cradle includes projecting members that capture the handheld personal computer and hold it securely in place. The cradle includes a position determining system that is adapted to determine position. Upon coupling the cradle to a handheld personal computer, the cradle is operable to determine position. Once position is determined, the determined position is displayed on the display of the handheld personal computer. The display can include a display of a moving map and an icon indicating the current position relative to the map. All required hardware and software for storing the map database and for determining position are included within the cradle.

Abstract: Streams of data packets and timing pulses are received from a source. Time stamping of the data packets is carried out largely independent of individual timing pulses. A normalised pulse time of arrival is calculated, preferably as a running average over the most recent arrivals. Times of applicability for the content of the packets can then be calculated according to a predetermined relationship between the order of arrival and of corresponding pulses and packets. Data acquisition may take place from an external or internal data source. An example external source is a GPS receiver.

Abstract: The present invention is drawn to a light bar assembly for guiding the movement of a vehicle on a tilted surface. The light bar assembly is comprised of a housing having a light bar and a tilt sensor. The light bar is disposed in the housing and adapted to guide the movement of the vehicle. In addition, the tilt sensor is disposed in the housing and adapted to indicate the attitude of the vehicle. As such, the attitude of the vehicle is taken into consideration when the vehicle is being guided along the adjusted travel path on the tilted surface. Moreover, with the addition of the light bar assembly, an existing prior art guidance control system can be conveniently and economically upgraded to a robust system that includes the tilt sensor.

Abstract: A cellular telephone having a global positioning system (GPS) receiver using a blended combination of GPS signals from GPS satellites and GPS pseudolites for determining a location. The cellular telephone includes a cellphone transceiver and a GPS receiver. The cellular transceiver receives wireless downlink cellphone signals from the cell site transceiver and transmits wireless uplink cellphone signals to the cell site transceiver. The cell site transceiver passes voice and data from the downlink and uplink cellphone signals within a local area into the worldwide network of telephone services. The GPS receiver receives satellite GPS signals from GPS satellites and pseudolite GPS signals from GPS pseudolites. The GPS pseudolites augment the GPS satellites for the local area by broadcasting pseudolite GPS signals having location-determination information with a format that is similar to the format in the satellite GPS signals.