Abstract: Systems, devices and methods are provided to compress data, and in particular to code and decode data. One aspect of the present subject matter is a data structure. The data structure includes a field representing a decoding structure to decode canonical Huffman encoded data, and a field representing a symbol table. The decoding structure includes a field representing an accelerator table to provide a 2N-deep direct-index lookup to provide high-frequency symbols for high-frequency data and to provide bracketing indices for low-frequency data. The decoding structure also includes a field for a binary search table to provide a low-frequency symbol index using a binary search bounded by the bracketing indices provided by the accelerator table. The symbol table is adapted to provide a symbol associated with the low-frequency index.

Abstract: Systems, devices and methods are provided improving the accuracy, availability and integrity of GPS service. Specifically, the present invention provides a GPS device with the correction messages which are from the most accurate and desirable source while at the same time conserving processor and memory resources of the device. The method includes receiving GPS data. An SBAS signal from a first correction source is received. Ionospheric mask messages, for a number of grid points, in the received SBAS signal are analyzed. An abbreviated bounding region around a group of similar type grid points is constructed. The method further includes determining whether the position of the GPS device is within the abbreviated bounding region.

Abstract: A name of a thoroughfare is identified from at least one name for the thoroughfare in reference to a set of criteria. In one example, the set of criteria includes whether or not the thoroughfare is an interstate, whether or not a name is shielded, has a suffix, and/or has an identified prefix. Interstate thoroughfares are often identified by a shielded name of the interstate thoroughfare, and non-interstate thoroughfares are often identified by a non-shielded name of the non-interstate thoroughfare. The identified name includes a name which is most recognized or well-known for navigating.

Abstract: A method and system are provided for minimizing storage and processing of ionospheric grid point corrections transmitted from WAAS satellites in a global positioning system. Based upon a current location, the system creates a boundary around the current location and collects ionospheric grid point corrections within the boundary. The collected correction points are used to correct the position initially determined by a global positioning system.

Abstract: An apparatus and method for sealing an opening in a structure, e.g., an electronic device, are provided. The apparatus includes a cover, a fastening member and a receiving member. The cover is adapted to be pivotally coupled with the structure and positioned over the opening. The fastening member is adapted to be coupled with the cover and the receiving member is adapted to be coupled with the structure. The receiving member is further adapted to selectively engage the fastening member providing a water-tight seal over the opening. In one embodiment, the apparatus further includes a biasing member for selectively biasing the cover in one of two positions.her includes a biasing member for selectively biasing the cover in one of two positions.

Abstract: A computer program, method, and device for controlling the brightness of a display (10) by proportionally varying the voltage delivered to each pixel in the display (10) after the back light (12) for the display (10) has been dimmed to its approximate lowest level. The display (10) includes a back light (12); a display module (16) having an array of pixels that may be individually controlled to selectively block or pass light from the back light (12) to create a desired image; a user interface (24) for selectively adjusting brightness of the back light (12) to vary the amount of light passing through the pixels to control the brightness of the image; and a controller (22) for proportionally adjusting the luminosity of the pixels to further control the amount of light passing through the pixels to control the brightness of the image.

Abstract: Systems, devices and methods are provided for more efficient use of RAM and other resources in connection with a route calculation algorithm which quickly obtains a best or reasonable best path between two locations. The navigational aid device includes forced layer switching capabilities. The navigational aid device includes a processor and a memory adapted to communicate with the processor. The memory has cartographic data including any number of locations and data indicative of thoroughfares of a plurality of types connecting certain ones of the locations. The plurality of thoroughfares are organized in a hierarchy of detail levels. The processor operates on a route calculation algorithm to find a path between any two of the number of locations and the route calculation algorithm dynamically forces switching between different levels in the hierarchy of detail levels based on a set of criteria.

Abstract: A method and apparatus are provided for calculating potential paths through a roadway network defined at least partially by separate, but adjacent data maps. First and second data maps are provided that are indicative of roadway networks for different geographic regions bounded by region edges, at least one of which is common to both geographic regions. The data maps are adjacent, and one data map contains the first location while the other data map contains a roadway segment over which the potential paths may travel. Potential paths are planned from the first location through the first data map. When a current potential path intersects an edge of the first data map, the intersection is identified by coordinate data. A transition point is located in an adjacent data map based on the location where the current potential path intersects the edge of the first data map. The calculation method and apparatus continue from the transition point through the second data map toward the second location.

Abstract: A method and apparatus are provided for calculating potential paths between source and destination locations. First and second map databases are provided that are indicative of roadway networks for geographic regions bounded by region edges and containing source and destination locations. The first and second map databases, are non-adjacent, non-contiguous such that the region edges of the first map database are separate and distinct from region edges of the second map database. Potential paths are calculated through the roadway network of the first map database up to a node or segment at which each potential path intersects a region edge of the first map database, thereby defining a node/edge coordinate. A transition location is obtained in the second map database that geographically corresponds to the node/edge coordinate at which a given potential path intersected the region edge of the first map database.

Abstract: A method and system are provided for minimizing storage and processing of ionospheric grid point corrections transmitted from WAAS satellites in a global positioning system. Based upon a current location, the system creates a boundary around the current location and collects ionospheric grid point corrections within the boundary. The collected correction points are used to correct the position initially determined by a global positioning system.

Abstract: An equipment module, a module retention device, as well as a system and a method for mounting equipment modules are disclosed. The modules can be installed without tools, using the retention device. Each module includes a chassis unit which slides into a unit rack, which is in turn attached to a mounting frame. The entire assembly may be mounted to an instrument panel. The module retention device is attached to the chassis unit, typically engaging a slot on the rack. A rotating fastener secures the retention device in the engaged position. The method includes inserting an electronic module into the open end of a unit rack, sliding an engagement lug attached to a cam lever into engagement with a slot on the rack, electrically coupling a connector on the module with a connector on the rack, and attaching the rack to the mounting frame.

Abstract: A portable, handheld electronic navigation device includes an altimeter, a compass, and a GPS unit. An internal memory stores cartographic data, for displaying the cartographic data on a display of the navigation device. Accordingly, the device is capable of displaying cartographic data surrounding a location of the unit as determined by GPS, heading information as determined by the compass, and altitude information as determined by the altimeter. Additionally, through operation of an input, a user can cause the display to move, and thus display additional cartographic information, in the direction of the compass heading even when the user of the device is standing still. Furthermore, through utilization of a clock, such as the GPS clock, a user can determine altitude changes over time. Also, the altimeter of the navigation may be calibrated with altitude information entered by a user, with altitude information obtained from the cartographic or with altitude information derived from GPS.

Abstract: An apparatus is provided for removably mounting an electronic device to the dashboard of a vehicle. The apparatus includes a mount securable to the electronic device and a cradle fixed to the vehicle for receipt of the mount. The mount includes a plate for attachment to the electronic device and at least one flexible locking arm extending from said plate. The outwardly biased arm engages the cradle when the mount is secured to the cradle. The arm is deflected inwardly to allow the electronic device to be quickly and easily removed from the dashboard of the vehicle in a single motion.