APPENDIX382This navigation system calculates thecurrent vehicle position using satellitesignals, various vehicle signals, mapdata, etc. However, the accurate posi-tion may not be shown depending onthe satellite condition, road configura-tion, vehicle condition or other circum-stances.The Global Positioning System (GPS) de-veloped and operated by the U.S. Depart-ment of Defense provides an accurate cur-rent vehicle position, normally using 4 ormore satellites, and in some case 3 satel-lites. The GPS system...