Abstract: A system and method for storing and using data representing crossings of geographic features, and an associated product having the data embodied thereon, for use with a computer based navigation system, is disclosed. A computer-readable medium has computer-readable data embodied thereon that represents geographic features in a geographic region. The computer-readable data includes a plurality of data entities of a first type each of which represents a respective one of a plurality of linearly extending geographic features and a plurality of data entities of a second type each of which represents a respective crossing at which one of the linearly extending geographic features represented by one of the plurality of data entities of the first type crosses over another of the linearly extending geographic features represented by another of the plurality of data entities of the first type at a higher altitude.

Abstract: A geographic database for use with a navigation application program that provides navigation features to an end-user. The geographic database includes a plurality of data records of a first type and a plurality of data records of a second type. The plurality of records of the first type are organized into a plurality of parcels, each of which includes a plurality of data records of the first type and the plurality of records of the second type are organized into a plurality of parcels, each of which includes a plurality of data records of the second type. The parcels of data records of the first type are interleaved with the parcels of data records of the second type. This interleaving enables navigation functions that use these different types to access these different types more quickly and efficiently, thereby enhancing navigation system performance.

Abstract: The invention provides a method and system for providing route guidance and other information from a base unit to a remote unit in response to a request from the remote unit. A query is formatted at the remote unit, the query including the request, and is transmitted from the remote unit to the base unit. Requested route guidance information is calculated at the base unit in response to the query, using a large up-to-date database located at the base unit. A response to the query is formatted at the base unit, the response including route guidance information. The response is then transmitted from the base unit to the remote unit for display. The transmission is made in a compact form through the use of maneuver arms and combined maneuver arms and through the use of tokenized forms. A maneuver arm represents a road at an intersection, for depiction on a display, by one or two endpoint coordinates.

Abstract: The invention provides a method and system for providing route guidance information from a base unit to a remote unit in response to a request from the remote unit. The remote unit may be a mobile unit or a fixed unit. A query is formatted at the remote unit, the query including the request, and communicated from the remote unit to the base unit. The requested route guidance information is calculated at the base unit in response to the query, using a database located at the base unit. A response to the query is formatted at the base unit, the response including the route guidance information. The response is communicated from the base unit to the remote unit for display.

Abstract: A program and method for a map display tool for use with a navigation system and used with a map database. The map display tool is adapted to render a map on a display or in a graphics buffer for a predetermined geographic region. The map display tool includes a map processing layer for performing the essential data manipulation, a graphics interface layer that maintains a series of look up tables with graphics commands, and a primitive layer customized to interact with an underlying graphics platform and the graphics interface layer. The map display tool renders a map by retrieving data items from the map database and processing each data item. Shape information is rendered on a screen or in a graphics buffer, name information is buffered and sorted to optimize filtering, prioritization, spatial conflicts resolution and other tasks prior to rendering.

Abstract: A method and system for supporting alternative names of geographic locations with a navigation application program that uses a geographic database stored on a computer-readable medium. The alternative names of geographic locations include names in a plurality of different languages. Included are one or more language filters. Each of the one or more language filters associates the data records in the geographic database that are used as names for geographic locations with one or more of the plurality of different languages. A routine uses the one or more language filters so that the navigation application program can use names for geographic locations that are valid in an access language selected from among the plurality of different languages.

Abstract: A method and system for managing memory resources in a system used in conjunction with a navigation application program that accesses geographic data. The geographic data are comprised of a plurality of data records. The plurality of data records are organized into parcels, each of which contains a portion of the plurality of data records, such that the data records in each portion of the plurality of data records that forms each parcel are accessed together. One or more buffers each that forms a contiguous portion of the memory of the navigation system is provided as a cache to store a plurality of parcels. One or more data structures located outside the contiguous portion of memory identify the parcels of data stored in the cache and the locations in the cache at which the parcels are stored. The one or more data structures located outside the contiguous portion of memory in which the parcels are cached are used to manage the parcel cache to use it efficiently.

Abstract: An improved method and system that provides for a data access interface layer in a navigation system. The navigation system is of the type that includes a navigation application software program that provides navigating features to a user of the system and a geographic database stored on a computer-readable storage medium wherein the geographical database includes information relating to the geographical region about which the navigation system provides the navigation features to the user. The data access interface layer is preferably stored in the navigation system as a library of software functions. The data access interface layer operates in conjunction with the navigation system application software. The data access interface layer isolates the navigation application software from the geographic data which are stored on the storage medium. The data access interface layer intercepts requests by the navigation application software for geographic data.

Abstract: A system for updating, enhancing and/or refining a geographic database. A geographic database includes data representing physical features in the geographic region, and, optionally, attributes of such features. The system includes a plurality of data collecting sensors. Each of the data collecting sensors is installed in a separate one of a plurality of vehicles each of which is capable of traveling on roads in a geographic region. Each of the data collecting sensors provides outputs indicative of one or more features in the geographic region as the vehicle in which it is installed travels on the roads in the geographic region. A computer program executes a feedback process on the geographic database using the outputs of the data collecting sensors. A first part of the feedback program compares the outputs of the data collecting sensors to the data identifying the physical features and provides results representative of the comparisons.

Abstract: A geographic database for use with a navigation application program that provides navigation features to an end-user. The geographic database includes data entities that represent segments of roads and additionally includes data entities that represent aggregations of segments of roads. The data entities that represent aggregations of segments of roads are used during a route calculation by the navigation application to suppress evaluation of roads of lesser functional rank thereby enhancing performance of the navigation system. According to one aspect, each of the data entities that represent segments of roads that represents a segment of a road that together with at least one other segment of a road forms part of an aggregation which is represented by one of the data entities that represent aggregations of segments of roads includes a reference thereto.

Abstract: A system and method of providing incremental updates for a geographical data set for use in navigation systems. The system and method include organizing updates of geographical data set into a series of transactions. Each of the transactions includes a transaction identifier that uniquely identifies the transaction, and n steps to be applied to the geographical data set to complete the transaction. All the steps of the transaction are required to be successfully applied in order for the transaction to be completed, otherwise, the entire transaction is not applied.

Abstract: A system and method for storing data in a computer-readable database to represent curved geographic features. The database can be used in a navigation system. A computable function is used to define a curved line that represents the curved geographic feature. The computable function may be a polynomial equation whose shape is defined by its coefficients. In one embodiment, the polynomial equation is a type of spline curve, in particular a Bezier curve whose shape is defined by control points. The coefficients of the polynomial equation are associated with data representing the curved geographic feature. In the case in which the polynomial equation is a Bezier curve, the control points for generating the Bezier curve are associated with the data representing the curved geographic feature. These control points are stored in the database and are used in displaying the curved geographic feature.

Abstract: A system and method for distributing information for storage media, and in particular, for distributing updated navigation data, such as geographical data and navigation application programs, contained on storage media and used in in-vehicle navigation systems. A plurality of local repositories are located in a geographical area. Each of the local repositories includes updated versions of navigation data for the navigation systems. Owners of vehicles having navigation systems may visit any of the repositories from time to time where they can obtain updated versions of the navigation data for their navigation systems. Subscriptions for obtaining updated navigation data would be available to the owners of navigation systems that would entitle them to obtain updated navigation data from the repositories. Procedures for updating the local repositories are also provided. The system and method can be used for updating other types of software.

Abstract: A system and method for acquiring differentially corrected GPS data for forming a digital database of road geometry in a geographic region. A vehicle having a GPS receiver and a DGPS demodulator located therein is driven on roadways in the geographic region. The GPS receiver receives standard GPS signals and the DGPS demodulator receives DGPS signals which are used to correct the standard GPS signals. The corrected GPS signals are stored where they can be processed to create a digital database. Alternately a GPS receiver is positioned at a stationary location along with a portable DGPS demodulator. A vehicle having a GPS receiver located therein is driven on roadways in the geographic region. The GPS receiver at the stationary location is continuously operated and the DGPS demodulator is operated once to receive a DGPS signal. The DGPS demodulator can then be moved to another geographic region.

Abstract: A system and method for arranging and storing a plurality of records of geographic data, wherein each record corresponds to a physical feature having a physical location in a geographic region. The method and system comprise arranging the records of geographic data into a plurality of parcels. Each parcel includes records of geographic data that represent features having physical locations encompassed within a corresponding associated rectangular area located in the geographic region. The size and location of each such rectangular area associated with a parcel is determined by a series of divisions of a bounding rectangle that encompasses all of the features represented by the plurality of records into further rectangular areas. Each division, subsequent to an initial division, is made on a rectangular area resulting from the preceding division.

Abstract: An improved method and system for storage of geographic data on physical storage media. The geographic data are stored in a manner that facilitates and enhances use and access of the data by various navigation application functions in navigation systems that use the data. The geographic data includes a parcelization that separates the geographic data into parcels having less than or equal to a maximum parcel size but having at least a desired fill percentage. The parcelization method also provides for a division arrangement that facilitates addressing and identification of the parcels. According to a further aspect, the geographic data includes special nodal entities that are used to collapse complex intersections, such as roundabouts, cloverleaves, and divided highways, into simpler data representations. The special nodal entities are associated with road segment data entities and used in a route calculation program in place of regular node entities.

Abstract: A system and method for making and using a geographic database. The geographic database represents a geographic region and is used with a navigation application program. The geographic database includes a plurality of data entities each of which represents a physical feature in the geographic region. The plurality of data entities are separated into a plurality of parcels each of which contains a grouping of data entities that represent features in the geographic area encompassed within a separate one of a plurality of rectangles which together encompass all the features in the entire geographic region represented by all of the plurality of data entities. Each of the plurality of data entities has a data entity ID.

Abstract: A system and method for distributing information for storage media, and in particular, for distributing updated navigation data, such as geographical data and navigation application programs, contained on storage media and used in in-vehicle navigation systems. A plurality of local repositories are located in a geographical area. Each of the local repositories includes updated versions of navigation data for the navigation systems. Owners of vehicles having navigation systems may visit any of the repositories from time to time where they can obtain updated versions of the navigation data for their navigation systems. Subscriptions for obtaining updated navigation data would be available to the owners of navigation systems that would entitle them to obtain updated navigation data from the repositories. Procedures for updating the local repositories are also provided. The system and method can be used for updating other types of software.

Abstract: A system and method of providing incremental updates for a geographical data set for use in navigation systems. The system and method include organizing updates of geographical data set into a series of transactions. Each of the transactions includes a transaction identifier that uniquely identifies the transaction, and n steps to be applied to the geographical data set to complete the transaction. All the steps of the transaction are required to be successfully applied in order for the transaction to be completed, otherwise, the entire transaction is not applied.

Abstract: An improved method and system for a depleted uranium calorimeter detector used in high energy physics experiments. In a depleted uranium calorimeter detector, the energy of a particle entering the calorimeter detector is determined and the output response of the calorimeter detector is compensated so that the ratio of the integrated response of the calorimeter detector from a lepton to the integrated response of the calorimeter detector from a hadron of the same energy as the lepton is approximately equal to 1. In the present invention, the energy of a particle entering the calorimeter detector is determined as a function of time and the hadron content of the response of the calorimeter detector is inferred based upon the time structure of the energy pulse measured by the calorimeter detector. The energy measurement can be corrected based on the inference of the hadron content whereby the resolution of the calorimeter can be improved.