| 摘要 |
A portable electronic navigation apparatus and method utilizes universal latitude and longitude coordinates of geographic points and landmarks for determining current location or a specific destination and the distance and bearing thereof relative to landmark data input by the user. Latitude and longitude of population centers (e.g., cities, towns), major buildings, airports, and other landmarks in a geographical area are stored in a first memory. Latitudinal and longitudinal data for roadways in the area are stored in a second memory. A third permanent memory stores programs to; calculate the distance between two known points; look up and retrieve stored information; store and erase data upon the user's instruction; accept corrections to stored data; and to display the data on a screen in relation to its latitude and longitude along with name, mileage, and bearing or destination data corresponding to the related geographical feature or landmark. Destination, current or hypothetical location, latitude and longitude adjustments, other data, and requests for navigational information is input by a keyboard. Roads, population centers, airports, buildings, other landmarks, mileages, and bearings or directions according to the oeprator's request is displayed visually or vocally. The user may specify a radius around the current or destination location, and receive the distance between the destination and any other geographical feature, landmark, or roadway within the designated radius or within the designated path width.
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