Abstract: A method of compressing data output from one or more accelerometers configured to be transported, carried or worn by a user is provided. Acceleration values indicative of the movement of the user are measured at a first frequency and values representative of the measured acceleration values are generated at a second frequency, which is lower than the first frequency. The step of generating comprises: defining a plurality of time windows, each time window containing a plurality of measured acceleration values; and applying a transformation to the measured acceleration values within each time window to generate a plurality of transformed values. For each time window, storing at least one of said plurality of transformed values and/or one or more parameters associated therewith.

Abstract: This invention concerns a computer-implemented method for determining a number of lanes on a road. The method comprises receiving an image, the image being a photographic image of the road or an image derived from the photographic image of the road, carrying out an analysis of the image to identify lane dividers of the road and determining a number of lanes into which the road is divided from the identification of the lane dividers. The method may comprise determining a confidence level for the determined value for the number of lanes. Map data of a plurality of roads may be generated using the value for the number of lanes determined from the computer-implemented method.

Abstract: A method for use in forming an image of an object comprises setting a value of an attribute of an image of an object according to a measured reflectance of the object. The image of the object thus formed may be realistic and may closely resemble the actual real-world appearance of the object. Such a method may, in particular, though not exclusively, be useful for providing a realistic image of a road surface and any road markings thereon to assist with navigation. Setting a value of an attribute of the image of the object may comprise generating an initial image of the object and adjusting a value of an attribute of the initial image of the object according to the measured reflectance of the object to form an enhanced image of the object. A method for use in navigation comprises providing a navigation system with data associated with an image formed using such a method. An image formed using such a method and a map database containing such an image are also disclosed.

Abstract: A navigation system for use in a vehicle (402). The system includes an absolute position sensor, such as GPS, in addition to one or more additional sensors, such as a camera, laser scanner, or radar. The system further comprises a digital map or database that includes records for at least some of the vehicle's surrounding objects (400). These records can include relative positional attributes with respect to a reference axis (404). As the vehicle (402) moves, sensors sense the presence of at least some of these objects (400), and measure the vehicle's relative position to those objects. This information is used to determine the vehicle's instantaneous lateral offset (428) relative to the reference axis (404), and support features such as enhanced driving directions, collision avoidance, or automatic assisted driving. The system also allows new objects (408, 414) to be attributed using relative positioning, and thereby factored into the enhanced navigation features.

Abstract: A method of generating a geodetic reference database product is disclosed The method comprises acquiring mobile mapping data captured by means of digital cameras, range sensors and position determination means including GPS and IMU mounted to a vehicle driving across the earth surface, the mobile mapping data comprising simultaneously captured image data, range data and associated position data in a geographic coordinate system. Linear stationary earth surface features are derived from the mobile mapping data by processing the image data, range data and associated position data. 3D-models are generated for the linear stationary earth surface features in the geographic coordinate system from the image data, range data and associated position data and stored in a database to obtain the geodetic reference database product. A 3D-model could include an image representing the colors of the surface of the 3D model or a set of smaller images representing photo-identifiable objects along the model.

Abstract: A method for detecting inland barrier (16, 16?) crossings (24, 26, 30) using speed layers from community input probe traces in combination with a digital map. Inland barrier crossing specifications are detected and/or validated using information about the speed of probes that actually cross the barrier (16, 16?). A bridge (26) across the inland barrier (16) is inferred if the velocity average for barrier crossing probe traces is greater than an established threshold value. Conversely, a ferry (24) is inferred if the average velocity for barrier crossing probe traces is less than the established threshold value. When there is a prominent gap in the data for the barrier crossing probe traces, a tunnel (30) is inferred.

Abstract: A computerised method of creating map data from a plurality of trips where each trip comprises position data derived from the positions of at least one navigation device 200 over a period of time, the method comprising using a processing circuitry to perform the following steps: i. processing the position data; ii. determining from the processing the believed accuracy of the position data constituting a trip; iii. reducing the weight applied to and/or removing position data in which the belief is below a predetermined threshold to generate filtered position data; iv. deriving information about the road 700 based upon the filtered position data; and v. generating further map data.

Abstract: A method of evaluating an attribute of a point of interest 150 comprises associating a region 152 with the point of interest 150; and evaluating 148 the attribute according to a comparison of position data 154,156,158 of a plurality of users with position data defining the associated region.

Abstract: This invention relates to a method for updating digital maps and for matching global navigation devices to a digital map. Such navigation devices rely upon GPS signals (20, 24) from satellites (22, 26). One well-documented cause of position error in navigation devices arises from the phenomenon of GPS multi-path. It has been observed that GPS multi-path errors in the latitude/longitude direction are highly correlated with errors in altitude. By comparing altitude value of GPS probe data with reference specifications for altitude, unreliable probe data (outliers) can be easily identified and culled. Such techniques can be used as well by a mobile navigation device to confirm a match to a particular road segment and if not revert to other positioning techniques such as inertial guidance systems and the like. If the local altitude is not reliably known, an estimation can be derived directly from the collected probe data.

Abstract: A method of evaluating an attribute of a point of interest 150 comprises associating a region 152 with the point of interest 150; and evaluating 148 the attribute according to a comparison of position data 154,156,158 of a plurality of users with position data defining the associated region.

Abstract: A computerised method of creating map data from a plurality of trips where each trip comprises position data derived from the positions of at least one navigation device over a period of time, the method comprising using a processing circuitry to perform the following steps: i. processing the position data; ii. calculating, from the processing of the position data, trip terminal positions at which the navigation device started to generate positions and/or stopped generating positions and which provide an end point of a trip; iii. performing statistical analysis on the terminal positions in order to determine origin locations at which trips commonly terminate and/or originate; iv. generating further map data, which comprises the origin locations.

Abstract: A method of generating a geodetic reference database product is disclosed The method comprises acquiring mobile mapping data captured by means of digital cameras, range sensors and position determination means including GPS and IMU mounted to a vehicle driving across the earth surface, the mobile mapping data comprising simultaneously captured image data, range data and associated position data in a geographic coordinate system. Linear stationary earth surface features are derived from the mobile mapping data by processing the image data, range data and associated position data. 3D-models are generated for the linear stationary earth surface features in the geographic coordinate system from the image data, range data and associated position data and stored in a database to obtain the geodetic reference database product. A 3D-model could include an image representing the colors of the surface of the 3D model or a set of smaller images representing photo-identifiable objects along the model.