Abstract: A method of determining density of a map is described along with an apparatus and computer-readable medium comprising instructions therefore. The method comprises determining one or more nodes of a quad tree applied to a map with which a predetermined query region intersects, calculating a cumulative data size of the query region based on a data size of the one or more intersecting nodes, and determining an average density of the query region based on the query region area and the cumulative data size.

Abstract: A navigation device includes a computer platform that includes a global positioning system (GPS) receiver operable to acquire and track a GPS signal, a processor assembly, and a memory. The memory includes at least one of last recorded Ephemeris and Almanac information, and a GPS velocity vector determination module operable to generate a velocity vector output in the absence of current Ephemeris based upon the tracked GPS signal and the last recorded GPS information. A method of vehicle navigation in the absence of current Ephemeris includes acquiring and tracking a GPS signal, retrieving from a memory a last recorded location of a vehicle, setting a dead reckoning startup location equal to the last recorded location, retrieving from a memory at least one of a last recorded Ephemeris and Almanac, determining a current velocity vector and determining a current location based upon the velocity vector and the dead reckoning startup location.

Abstract: A method of determining density of a map is described along with an apparatus and computer-readable medium comprising instructions therefore. The method comprises determining one or more nodes of a quad tree applied to a map with which a predetermined query region intersects, calculating a cumulative data size of the query region based on a data size of the one or more intersecting nodes, and determining an average density of the query region based on the query region area and the cumulative data size.

Abstract: A navigation device includes a computer platform that includes a global positioning system (GPS) receiver operable to acquire and track a GPS signal, a processor assembly, and a memory. The memory includes at least one of last recorded Ephemeris and Almanac information, and a GPS velocity vector determination module operable to generate a velocity vector output in the absence of current Ephemeris based upon the tracked GPS signal and the last recorded GPS information. A method of vehicle navigation in the absence of current Ephemeris includes acquiring and tracking a GPS signal, retrieving from a memory a last recorded location of a vehicle, setting a dead reckoning startup location equal to the last recorded location, retrieving from a memory at least one of a last recorded Ephemeris and Almanac, determining a current velocity vector and determining a current location based upon the velocity vector and the dead reckoning startup location.

Abstract: A navigation system for providing navigation information to a user responsive to user commands includes (1) a user device for issuing user commands and displaying a user interface to the user and (2) a navigation device for connecting to the user device and receiving user commands from the user device and transmitting navigation information to the user device. The information received from the user device includes updated map information, traffic information, news information, weather information, event-related information, business-related information, and user-specified information. The navigation device performs route following based on commands received from the user device and transmits routing instructions to the user device. The navigation device and user device are separately operable by a user.

Abstract: A method of and computer system for assisting GPS position determination is described. Ephemeris and updated almanac information for a GPS satellite is received over a datalink. Based on the received updated almanac information and GPS parity algorithms, data bits of the GPS signal are reconstructed. Based on the current time, the reconstructed data bits are synchronized with the time of reception of a GPS signal from a satellite currently in view. The reconstructed data bits are subtracted from the received GPS signal at the synchronized time. A coherent integration of the received GPS signal over the time period corresponding to the reconstructed data bits is performed to obtain a GPS pseudo-range measurement. The GPS receiver position is determined using the generated, synchronized pseudo-range measurement and the ephemeris information received over the datalink.

Abstract: A method of and computer system for assisting GPS position determination is described. Ephemeris and updated almanac information for a GPS satellite is received over a datalink. Based on the received updated almanac information and GPS parity algorithms, data bits of the GPS signal are reconstructed. Based on the current time, the reconstructed data bits are synchronized with the time of reception of a GPS signal from a satellite currently in view. The reconstructed data bits are subtracted from the received GPS signal at the synchronized time. A coherent integration of the received GPS signal over the time period corresponding to the reconstructed data bits is performed to obtain a GPS pseudo-range measurement. The GPS receiver position is determined using the generated, synchronized pseudo-range measurement and the ephemeris information received over the datalink.

Abstract: A navigation system for providing navigation information to a user responsive to user commands includes (1) a user device for issuing user commands and displaying a user interface to the user and (2) a navigation device for connecting to the user device and receiving user commands from the user device and transmitting navigation information to the user device. The information received from the user device includes updated map information, traffic information, news information, weather information, event-related information, business-related information, and user-specified information. The navigation device performs route following based on commands received from the user device and transmits routing instructions to the user device. The navigation device and user device are separately operable by a user.

Abstract: A technique for displaying topographical data, for example, on a screen of a portable hand-held device includes: optionally receiving GPS (Global Positioning System) signals and generating a digital output indicative of a position location of the display device in response to the received GPS signals or inputting location data manually to produce an image on a display screen of the device in response to the digital output; and storing true digital elevation data as compressed cells and decompressing on-the-fly only data needed to provide elevation data for an image area displayed on the display screen.

Abstract: A technique for displaying topographical data, for example, on a screen of a portable hand-held device includes: optionally receiving GPS (Global Positioning System) signals and generating a digital output indicative of a position location of the display device in response to the received GPS signals or inputting location data manually to produce an image on a display screen of the device in response to the digital output; and storing true digital elevation data as compressed cells and decompressing on-the-fly only data needed to provide elevation data for an image area displayed on the display screen.

Abstract: A method and apparatus for the identification and quantification of a vapor, or a number of vapors, in air mixtures is discussed. The method includes calibration of a vapor responsive sensor, or a plurality of vapor responsive sensors, to known concentrations of the vapors of interest or to known concentrations of potential interfering vapors. The calibrations result in sensor response vectors which are derived from the transient signals observed as the vapors are sorbed and desorbed on the sensors. Detection of vapors in complex mixtures is effected by subjecting the apparatus to the mixture and measuring the sensor response, or plurality of sensor responses, and then applying multidimensional statistical analysis or filtering methods to this data, using the precalibrated response vectors as the basis set for deconvolution.