Pioneer AVIC N4 Owner's Manual - Page 143

NAVI/AV current position. Setting the DVD Map Disc to navigation automatically resets the route from your current location to your destination. TRAFFIC icon during the memory navi mode • XM NavTraffic-related data for a "Zone" (e.g., Zone 1 contain ID, OR, WA) only can be memo- rized. Therefore, if appears on the screen when crossing a zone border, you will need to insert the disc to use the XM NavTraffic function. Touching allows you to check the locations of the traffic information along the route. However, you cannot perform rerouting. The accuracy of the GPS information depends on how good the reception is. When the signals are strong and reception is good, GPS can determine latitude, longitude and altitude for accurate positioning in three dimensions. But if signal quality is poor, only two dimensions, latitude and longitude, can be obtained and positioning errors are somewhat greater. Appendix Operation outside the memorized area When the vehicle leaves the memorized area, the functions will be limited. • The auto reroute function does not work. • You can only display a larger scale map. The map display will automatically change to a 25 mi (or 50 mi) scale. • The map matching function will not be available. Therefore, the position of your vehicle may be misaligned. • The navigation guidance will only be available when arriving at your destination. Other guidance is not possible (this includes no display of direction arrows). To cancel these limitations, insert the DVD Map Disc to the navigation system. Positioning Technology The navigation system accurately measures your current location by combining the positioning by GPS and by Dead Reckoning. Positioning by GPS The Global Positioning System (GPS) uses a network of satellites orbiting the Earth. Each of the satellites, which orbit at a height of 68 900 000 feet (21 000 km), continually broadcasts radio signals giving time and position information. This ensures that signals from at least three can be picked up from any open area on the ground's surface. Positioning by dead reckoning The 3D Hybrid Sensor in the navigation system also calculates your position. The current location is measured by detecting driving distance with the speed pulse, the turning direction with the Gyrosensor and inclination of the road with the G sensor. The 3D Hybrid Sensor can even calculate changes of altitude, and corrects for discrepancies in the distance traveled caused by driving along winding roads or up slopes. Also, the navigation system learns the driving conditions and stores information in the memory. Thus, as you drive more, the precision of the positioning becomes more accurate. The method of positioning changes as follows depending on whether the speed pulse of your vehicle is detected or not: 3D hybrid mode This is active when the speed pulse is detected. Inclination of a street can be detected. Simple hybrid mode When the speed pulse is not detected, positioning is performed in this mode. Only horizontal movement is detected, so it becomes less accurate. Also, when the positioning by GPS is not available, such as when your vehicle enters a long tunnel, the discrepancy between your actual and calculated position may become bigger. 141