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 to produce orthogonal beams includes a laser diode operating in conjunction with a collimating lens, an aperture, and a simple compact optic. Three collimated beams are directed toward an optic comprised of components that are bonded together. Beams are reflected from two optical components at right angles to produce plumb beams. Additionally, a beam is reflected from the optic at a right angle, as well as transmitted through the optic, to produce square and level beams. All four beams are orthogonal to each other, have relatively equal power, and are aligned and oriented so as to appear to be originating from a coincident point. Optionally, a fifth orthogonal beam may be produced. An optic in the shape of a cuboid comprised of six small components is also disclosed.

Abstract: A GPS information service system for providing supplemental GPS location correction and signal acquisition information to subscribers. A GPS information server broadcasts GPS information encrypted with subscription keys. Remote GPS subscription unit receive the key enablers for the subscription keys in service activation (SAM) messages for the services for which they have subscribed and then use the subscription keys to decrypt the GPS information. In order to prevent unauthorized use, the SAM messages have signatures derived from identifications of the remote GPS subscription units using an unsymmetrical signature algorithm.

Abstract: A rotor shaft is supported in a housing of a rotor assembly for a laser level. Bearings support the rotor shaft for rotation relative to the housing. An adhesive fixes an outer race of at least one of the bearings in position between the rotor shaft and the housing. The adhesive is a low viscosity, quick setting anaerobic adhesive, which when cured prevents angular drift of the shaft relative to the housing by eliminating the clearance that would have existed between the outer race and the housing.

Abstract: A device for spatial positioning systems includes a programmable measurement filter that is dynamically tuned by the device signal processing unit. The signal processing unit analyzes available data including the measurement signal to determine the likelihood that a detected measurement comprises true device movement and adjusts the measurement filter bandwidth accordingly.

Abstract: A positioning system or synthetic phase processor or rover station for providing high integrity positions with graduated accuracies. The positioning system includes one or more real time kinematic (RTK) reference stations for receiving GPS signals at established reference positions and measuring reference phases. The positioning system or the rover station selects a synthetic offset vector and uses the synthetic offset vector for inferring synthetic reference phases to a synthetic position. The rover station uses the synthetic reference phases with actual or virtual reference positions for determining a rover position having an added positional error controlled by the synthetic offset vector. For another embodiment a secure rover station dithers a secure position with a synthetic offset vector for providing an unsecure rover position having the added positional error.

Abstract: A self-leveling laser alignment tool and method thereof which provides a laser beam in a substantially truly level or plumb orientation are disclosed. Magnetic attraction is used to compensate for leveling errors of an approximately or partially leveled pendulum platform that is suspended from a flexible suspension element having a predetermined material stiffness. The material stiffness of the suspension element is compensated by using a magnet which pulls the pendulum platform into an orientation that is substantially truly level and plumb.

Abstract: A method of steering a vehicle along a predetermined, or real time path by using a steering control algorithm. The vehicle includes a navigation system and a navigation antenna. The navigation antenna is mounted on the vehicle at an optimum antenna position, whereas the steering control algorithm assumes a nominal antenna position at a predetermined reference point. The method comprises the following steps: (A) obtaining a set of positioning data of the vehicle by using the navigation system and by using the navigation antenna mounted at the optimum antenna position; (B) modifying the set of positioning data of the vehicle; (C) measuring a steering angle(s) of the front wheels of the vehicle relative to a predetermined reference direction(s); (D) calculating a correction(s) to the measured steering angle(s); and (E) performing a steering action by using the correction(s) to the measured steering angle(s) to move the vehicle along the predetermined, or real time path.

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: In a survey system involving either differential global positioning (DGPS) or robotic total station (RTS) systems, the mobile station includes the radio system in the surveyor pole and either connects the laser reflector system or the GPS to the top of the pole or provides a connector for releasably connecting the laser reflector system or GPS. Electric connections between the GPS or laser reflector system, and the radio system are made either by using the physical connector between the pole and the GPS or laser reflector system, or by providing separate electrical conductors and electrical connectors from the pole to the GPS or laser reflector. In the case of a RTS system the base station includes a GPS for locating the position of the base station. For added convenience, the pole may be formed in sections and the power supply may include an inductive coupling battery charger. Data communications may also take place using wireless technology such as Bluetooth.

Abstract: An apparatus and method using GPS for dynamically adjusting side-to-side positioning of a farm implement along a geographical path. The apparatus includes a global positioning system (GPS) antenna disposed on the farm implement, a GPS receiver coupled to the GPS antenna for determining a location of the GPS antenna, and a dual guidance computer for comparing the location to stored geographical coordinates of a desired path or providing a guide signal for offsetting the lateral position of an adjustable hitch or angling a wheel or ground rudder in a steerable implement for guiding the implement along the path; and a range extent signal for maintaining the offset of the hitch or steering angle of the implement within its dynamic range.

Abstract: The present invention is a method and system for controlling an electronic device. In one embodiment, a controller is coupled with a position determining component, and a motion detecting component. In one embodiment, the motion detecting component detects motion of the electronic device and generates a signal to the controller indicating the motion. The controller, in response to the signal, causes the position determining component to determine the geographic location of the electronic device. The geographic location is compared with a pre-defined zone and, in response to the comparing, a command is generated for controlling the electronic device.

Abstract: A laser transmitter adapted for use in small spaces such as pipes and sewers includes a housing having two exit windows positioned in generally orthogonal planes. The laser transmitter includes a leveling mechanism that is capable of directing a collimated beam through a select one of the two exit windows, in a generally horizontal direction at a specified grade irrespective of whether the laser transmitter is oriented generally horizontally or generally vertically.

Abstract: A self-leveling laser alignment tool and method thereof which provides a laser beam in a substantially truly level or plumb orientation are disclosed. Magnetic attraction is used to compensate for leveling errors of an approximately or partially leveled pendulum platform that is suspended from a flexible support member having a predetermined material stiffness. The material stiffness of the suspension member is compensated by using magnets which pulls the pendulum platform into an orientation that is substantially truly level and plumb.

Abstract: A laser beam receiver with non-interdigitated photosensors arranged in a repeating pattern of “n” channels of photosensors in each of “m” sectors is disclosed. The photocurrent from both the anode and cathode terminals of the photosensor is used to determine laser beam position. The repeating patterns connect one set of “n” channel amplifier channels with the corresponding set of “m” sector amplifier channels. The position of the laser beam is determined by its position relative to the sector and channel the laser beam impinges on. The laser beam position relative to sector boundaries is determined by the distribution of photosensor current into the “n” channels of amplifiers from the “n” photosensors within each sector. The sector of the photosensor the laser beam impinges on is determined by the distribution of photosensor current into the “m” channels of sector amplifiers from the “m” groups of “n” photosensors.

Abstract: A GPS information service system for providing supplemental GPS correction and signal acquisition information to subscribers. A GPS information server broadcasts GPS aiding information encrypted with subscription keys. A remote GPS subscription unit receives the key enablers for the subscription keys in service activation (SAM) messages for the services for which they have subscribed and then uses the subscription keys to decrypt the GPS aiding information. In order to prevent unauthorized access to the information, unsymmetrical signature generation and authentication algorithms are used for generating and authenticating signatures for the SAM messages.

Abstract: A device and method for detecting the relative position of reference light includes a plurality of photodetector arrays arranged in a generally vertical row. Each array includes a plurality of photodetector elements arranged in a generally vertical array row. The photodetector elements in the arrays are arranged in a generally vertically oriented, extended row. Each of the photodetector elements provides an electrical output when illuminated with the light. A plurality of weighting circuits is provided, each weighting circuit being associated with a respective one of the plurality of photodetector arrays.

Abstract: A system to produce orthogonal beams includes a laser diode operating in conjunction with a collimating lens, an aperture, and a simple compact optic. Three collimated beams are directed toward an optic comprised of components that are bonded together. Beams are reflected from two optical components at right angles to produce plumb beams. Additionally, a beam is reflected from the optic at a right angle, as well as transmitted through the optic, to produce square and level beams. All four beams are orthogonal to each other, have relatively equal power, and are aligned and oriented so as to appear to be originating from a coincident point. Optionally, a fifth orthogonal beam may be produced. An optic in the shape of a cuboid comprised of six small components is also disclosed.