Abstract: Receiver circuits are provided for detecting a target light source such as a swept laser beam. The circuits include a photodetector adapted to produce a first detector output signal and a second detector output signal where the relative amplitudes of the first and second detector output signals are related to the position of a swept laser beam impinging thereon. A first log signal is determined, which is based upon a logarithmic and optionally scaled calculation utilizing the first detector output signal. Correspondingly, a second log signal is determined, which is based upon a logarithmic and optionally scaled calculation utilizing the second detector output signal. The position of the beam is then computed based upon a subtraction of the second log output signal from the first log output signal.

Abstract: An MS DOS and MS WINDOWS compatible file system for avoiding loss of data in a memory unit if power is interrupted while new data is being written. The file system uses an ATA write command for erasing a data reserve sector and writing the modified data including the new data into the data reserve sector; erasing a control reserve sector and writing control data into the control reserve sector; erasing the intended operational sector and writing the modified data into the intended operational sector; and then uses an ATA erase command for erasing the control reserve sector. At power up or insertion of the memory unit, the control reserve sector is tested. If the control data is non-erased the host uses the copy of the modified data in the data reserve sector for replacing the data in the intended operational sector.

Abstract: A method and system are disclosed for providing WAAS like corrections using a server and processor on the Internet. For one method, satellite measurement data is collected. Satellite position error corrections are computed using the collected satellite measurement data. The computed satellite position error corrections are stored. The stored satellite position error corrections can then be later retrieved and used by a server and processor on the Internet.

Abstract: A survey system and method for determining the best source of position data for a particular application. The system includes both an optical unit and a satellite positioning system (SATPS) unit for obtaining position data. The optical unit includes a theodolite and an electronic distance meter for determining the position of a rover unit. The SATPS unit includes a SATPS antenna and a SATPS receiver for receiving signals from satellites of the SATPS and a radio for coupling the received signals to the rover unit. The present invention automatically determines the best source of position data. The best source of position data is then used to calculate the position of the rover unit.

Abstract: A GPS receiver having a fast acquisition of a GPS signal having a low signal-to-noise ratio. The GPS receiver uses an adjustable local frequency for iteratively downconvertig raw GPS signal samples to baseband GPS signal code data, combining a plurality of code epochs of the GPS signal code data in chunks and superchunks for providing representative code epochs, and correlates the representative code epochs to a replica code epoch for providing correlation times. Two or more correlation times are used to determine a correlation time difference. The correlation time difference is indicative of a residual frequency error. The error is used for correcting the local frequency. GPS pseudoranges are computed from the correlation times when the residual frequency error from the corrected local frequency is below a threshold.

Abstract: A transducer arrangement and method that generates control signals indicating relative positions of the ends of a hydraulically movable screed head. The generated control signals of the present invention are used by a conventional control circuit controlling the hydraulically movable screed head with laser receivers in a column block situation, which interrupts the reception of a laser beam from a laser transmitter by one of the laser receivers, to provide an estimated absolute position of the interrupted receiver side of the screed head until the column block situation clears. Normally, absolute measurements are available on both sides of the screed head via the laser receivers receiving the laser beam.

Abstract: A speech recognition equipped geographic information recording apparatus and method. In one embodiment, a mobile data terminal has a communication node therein. A geographic mapping system is integral with the mobile data terminal, and is coupled to the communication node. A speech recognition system adapted to receive verbal information is also coupled to the mobile data terminal. The speech recognition system is adapted to receive attribute data verbalized by an operator of the mobile data terminal. Additionally, the speech recognition system is adapted to receive operating commands verbalized by an operator of the mobile data terminal. The communication node of the mobile data terminal includes a transmitter for sending information from the mobile data terminal to a desired location, and a receiver for receiving information from a desired location. In the present embodiment, a real-time communication link exists between the mobile data terminal and the desired location.

Abstract: The present invention includes a system and method to implement Internet Protocol (IP) hosts on an application specific bus without disrupting the application specific bus. In one embodiment, an IP host determines the application specific bus address of a remote device, the remote device having an IP address in addition to the application specific bus address. The IP host formats a message conforming to the application specific bus, the message containing IP data and message identifiers. The IP host transmits the message on the application specific bus. In addition, the IP host negotiates for network access on the application specific bus. A destination IP host receives the message based upon the application specific bus address of the destination IP host and authenticates the message as an IP messages based upon the message identifiers. In addition, the destination IP host extracts the IP data from the message and processes the IP data by a conventional IP network processing protocol.

Abstract: A survey system and method for determining the best source of position data for a particular application. The system includes both a satellite positioning system (SATPS) and a non-SATPS unit for obtaining position data. The SATPS unit includes a SATPS antenna and a SATPS receiver for receiving signals from satellites of the SATPS and a radio for coupling the received signals to the rover unit. Data is collected using both the SATPS and non-SATPS methods to obtain a master data set. Data is selected and/or combined from the master data set to produce the data subset required for position determination. The basic SATPS method may also be augmented by the use of one or more reference stations at known locations.

Abstract: An indoor GPS clock using GPS signals lower that −143 dBm for issuing disciplined frequency and time standard signals. The indoor GPS clock includes a correlation machine using long integration periods for enabling the indoor GPS clock to operate with low signal levels; a carrier-less tracking loop for tracking the low level signals without carrier offset feedback, a clock bias loop for providing clock bias feedback; and a reference oscillator using the clock bias feedback for providing disciplined frequency and time signals having greater accuracy than is available in conventional GPS positioning receivers. The indoor GPS clock also includes a holdover driver providing compensation for predicted drift in clock bias error for disciplining the reference oscillator for several hours when the GPS signal is no longer being received.

Abstract: A method and system for sending messages that indicate position. In one embodiment, the message transmission device includes a message transmission unit that is coupled to a position determination system. A server is adapted to receive messages from the message transmission device. In operation, a first message is generated at the message transmission device. The position of the message transmission device is determined and is included in the message. The message is then sent to the server. The server then generates a second message that complies with any instruction indicated in the first message that relates to position. An instruction that relates to position can indicate routing, format, performance of a task, etc. By indicating return routing in the instruction, a user can obtain location in any of a number of desired formats without the need to store extensive databases in the message transmission device.

Abstract: A method of guiding a vehicle in adjacent swaths across terrain that may slope comprising the steps of: (1) determining the tilt of the vehicle with respect to Earth due to a slope of the terrain; (2) determining the position with respect to Earth of a predetermined location that is fixed relative to the vehicle; and (3) using the tilt and position determinations to provide information for guiding the vehicle to prevent gaps and overlaps between adjacent swaths as the slope changes.

Abstract: A portable construction layout tool generates laser beams in two or more directions related by a specific angle, such as 90°. The instrument emits two fans of light in such a way as to project a pair of lines on the floor, wall or other surface on which the instrument is mounted or placed, with the intersection of the two being visible rather than being a virtual intersection hidden beneath the instrument itself, enabling easier setup. Compared to rotating-beam instruments, the disclosed device is simpler by avoiding moving parts and provides for better visibility. In a preferred embodiment the non-collimated beam from a laser diode is used, and is passed through a cylinder lens to converge the beam on the narrower axis to generate the desired fan of light to be projected as a line.

Abstract: A laser reference system orients a reference plane of laser light generated by a transmitter so compensation is made for a rake angle between the first and second axes of the transmitter and an alignment axis and an axis perpendicular thereto. The transmitter includes an optical system arranged to generate a laser beam, the optical system projecting said laser beam radially along a rotational arc defined about a central rotational axis, thereby substantially defining a reference plane of laser light, and a positioning arrangement, coupled to said optical system, for adjusting the angular orientation of the optical system with respect to a first transmitter axis and with respect to a second transmitter axis. A detector is arranged to detect reception of the laser beam. The detector includes a generally vertically arranged row of detector elements. The detector further includes a transmitter for transmitting information regarding the location of said laser beam, as detected by said detector elements.

Abstract: A level sensing system for use with an excavating machine includes a light receiving sensor, mounted on the dipper stick of the machine, and an inclinometer, also mounted on the dipper stick of the machine. The sensor and inclinometer provide indications of the relative location of a beam of light and the inclination of the dipper stick. The inclinometer includes a gyroscopic inclination sensor and an accelerometer arrangement for sensing acceleration due to gravity and providing a static vertical reference. A position determining circuit is responsive to the sensor and the inclinometer and calculates the position of a pivot joint on the dipper stick to which a digging bucket is attached. The beam of light is a beam of laser light which is projected by a laser transmitter. An angle-measuring sensor may be provided for measuring the angular orientation between the dipper stick and a cutting edge of the bucket.

Abstract: A GPS weather data recording system for use with the dispensing of chemicals to agriculture fields. A GPS receiver is used to determine a series of positions of a vehicle and the velocity of the vehicle as the vehicle traverses an agricultural field. The series of positions and velocity trace the vehicle's ground track across the agricultural field. A wind sensor is used to measure wind velocity with respect to the vehicle. A data storage system is used for storing data measurements, such as the series of positions from the GPS receiver and a series of corresponding wind measurements from the wind sensor. A computer system is coupled to the data storage system. The computer system receives the series of vehicle positions and velocity from the GPS receiver and receives wind velocity measurements from the wind sensor.

Abstract: A method and a system for creating a Positional Reality scene of a plurality of real objects that represents a virtual reality scene with the correct positional information about real objects are disclosed. A Positioning Reality Image of each geometrical object is built by using an integrated Satellite Positional System (SATPS), and a Scanning Laser Sensor (SLS). If SATPS comprises an RTK GPS system, a Positioning Reality Image of each geometrical object is built in real time.

Abstract: A system providing a map and driving directions to a user of a user telephone for a remote location associated with a remote telephone number. The system includes the user telephone and a server connected through a telephone system. The user telephone includes a location number designator for designating a remote telephone number and an object decoder for decoding software objects such as a map object having map information for the area about the location of a remote address associated with the remote telephone number and a driving directions object having driving directions information for traveling to the remote location.

Abstract: A tamper-resistant apparatus located on board of an aircraft for avoiding a restricted air space (RAS) comprising: (a) a tamper-resistant restricted air space (TAP-RAS) database configured to include a set of coordinates that determines the RAS; and (b) a navigational processor configured to navigate the aircraft around the RAS, if a valid overriding command is not generated. The navigational processor includes: a Satellite Positioning System (SATPS) configured to substantially continuously obtain a set of real time position coordinates of the aircraft; a restricted airspace controller configured to receive a set of real time data including the set of coordinates that determines the RAS, the set of real time position coordinates; and configured to analyze the set of real time data in order to substantially continuously generate a set of real time commands; and an aircraft controller configured to navigate the aircraft utilizing the real time set of commands around the RAS.

Abstract: A transducer arrangement and method that generates control signals indicating relative positions of the ends of a hydraulically movable tool of a machine. The generated control signals of the present invention are used by a conventional control circuit of the machine to control the ends of the hydraulically movable tool having elevation receivers as an desired mode of operation or when reception by one of the elevational receivers of a elevational reference, which provides an absolute position of the ends of the tool, is interrupted. The conventional control circuit of the machine uses the generated signal of the transducer arrangement of the present invention to maintain a relative elevation position of one side of the tool to the absolute position of the other side of the tool as desired or until both receiver can reacquire the elevational reference.