Editing Automatic vehicle location (section)

=== Former LORAN-based locating ===
Motorola offered a 1970s-era system based on the [[United States Coast Guard]] [[LORAN]] maritime navigation system. The LORAN system was intended for ships but signal levels on the US east- and west-coast areas were adequate for use with receivers in automobiles. The system may have been marketed under the Motorola model name ''Metricom''. It consisted of an [[Low frequency|LF]] LORAN receiver and data interface box/modem connected to a separate two-way radio. The receiver and interface calculated a latitude and longitude in degrees, decimal degrees format based on the LORAN signals. This was sent over the radio as [[MDC-1200]] or MDC-4800 data to a system controller, which plotted the mobile's approximate location on a map. The system worked reliably but sometimes had problems with electrical [[noise]] in urban areas. Sparking electric [[trolley pole]]s or industrial plants which radiated electrical noise sometime overwhelmed the LORAN signals, affecting the system's ability to determine the mobile's geolocation. Because of the limited resolution, this type of system was impractical for small communities or operational areas such as a pit mine or port.