Abstract: RTK-GPS (realtime kinematic GPS) is one of the most precise positioning technology, with which users can obtain cm-level accuracy of the position in realtime by processing carrier-phase measurements of GPS signals. RTK-GPS has been already utilized for many applications like surveying, construction, agriculture and transportation. Recently, some researchers have tried to apply RTK-GPS to precise navigation of a mobile vehicle. On the condition under the clear sky, RTK-GPS provides fair performance even in the mobile environment. The performances includes availability of solutions, accuracy, TTF (time to fix), and reliability of integer ambiguity resolutions. However, in urban area like in a downtown street, RTK-GPS shows poor performance. One reason of the performance degradation on such condition is cycle slips. Cycle slips are defined as the discontinuities in the measured carrier-phase caused by loss-of-lock of signal tracking in GPS receivers.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A system for generating satellite positioning corrections includes a global correction module that generates a set of global pre-corrections based on modeling of global positioning error, a set of local correction modules that, for each local correction module of the set, takes input from a unique reference source and generates a set of local pre-corrections based on modeling of local positioning error; and a correction generator that generates a positioning correction from the set of global pre-corrections and the sets of local pre-corrections to correct a position of the mobile receiver.

Abstract: A positioning method whereby inertial positioning data is calculated based upon measurements of an Inertial Navigation System. Virtual satellite ranging data is then generated based upon the inertial positioning data. The virtual satellite ranging data is then combined with received satellite ranging data from one or more satellites forming part of a Global Navigation Satellite System (GNSS). A GNSS positioning solution is then calculated based upon the combined received satellite ranging data and the virtual satellite ranging data.

Abstract: Image display apparatus comprising two or more arrays of light sources is described. Each array is rotatable around a common axis, and the light sources in each array are arranged so that each light source traverses along a unique path around the common axis. A controller is adapted to modulate the intensity of light emitted by each light source as it traverses its respective unique path such that the light sources in combination cause a desired image to be visible to an observer by virtue of persistence of vision.

Abstract: A display module is disclosed, which comprises at least one light source movable along a predetermined path and a controller adapted to modulate the intensity of light emitted by the at least one light source as it moves along the predetermined path so as to cause a desired image to be visible by virtue of persistence of vision. The display module further comprises a drive system for causing the at least one light source to move along the predetermined path and a coupling system adapted to ensure the drive system causes the at least one light source to move, in use, along the predetermined path in synchrony with the light sources on one or more adjacent display modules.

Abstract: A positioning method whereby inertial positioning data is calculated based upon measurements of an Inertial Navigation System. Virtual satellite ranging data is then generated based upon the inertial positioning data. The virtual satellite ranging data is then combined with received satellite ranging data from one or more satellites forming part of a Global Navigation Satellite System (GNSS). A GNSS positioning solution is then calculated based upon the combined received satellite ranging data and the virtual satellite ranging data.

Abstract: A method of repairing a damaged portion of an underground pipeline positioned within a subterranean formation below the surface of the earth and having a flowbore. In some embodiments, the method includes inserting one or more pipe sections into the flowbore, the one or more pipe sections coupled and forming a throughpassage, positioning the one or more pipe sections within a damaged portion of the pipeline, disposing an expansion device within the throughpassage, and displacing the expansion device along the throughpassage, wherein the one or more pipe sections are radially expanded into engagement with at least the damaged portion of the pipeline.

Abstract: Image display apparatus comprising two or more arrays of light sources is described. Each array is rotatable around a common axis, and the light sources in each array are arranged so that each light source traverses along a unique path around the common axis. A controller is adapted to modulate the intensity of light emitted by each light source as it traverses its respective unique path such that the light sources in combination cause a desired image to be visible to an observer by virtue of persistence of vision.

Abstract: A memory controller for accessing a memory module comprising a plurality of memory banks. The memory controller is operable to write copies of program data to one or more memory banks according to the size of the program data. The memory controller is additionally operable to read program data, e.g. in response to an access request, from whichever memory bank is next available for access.

Abstract: Tubular ends are heated to a predetermined temperature above 1200 degrees Celsius and surrounded by a shield gas when the tubular ends are pressed together to form forge welded tubular ends. The forge welded tubular ends are then cooled down rapidly from said temperature above 1200 to at most 600 degrees Celsius within 3 minutes after the forge welding operation.

Abstract: A pipeline.

Abstract: An improved method of permanently marking the location of a tubular joint, the method including creating a cavity into the end surface of one of the tubular ends that are to be joined by a forge weld or screw thread connection, inserting a marker into said cavity and subsequently joining the tubular ends.

Abstract: The invention relates to a method for forge welding tubulars such that formation of upsets in the welding zone is minimized which involves shaping the tubular ends that are to be welded together into an inwardly sloping configuration such that when the tubular ends are heated during the forge welding process the heated tubular ends deform as a result of thermal expansion into a substantially longitudinally oriented cylindrical shape.