US Patent 7561969 Navtex receiver

Upon receiving a NAVTEX broadcast signal, a NAVTEX receiver reconstructs text data, detects a special character string including numerals followed by “N” or “S” and numerals followed by “E” or “W” in this order contained in latitude/longitude information, and extracts the latitude/longitude information from a textual sentence containing this special character string. Using the extracted latitude/longitude information and information on latitude/longitude of the receiver, the NAVTEX receiver calculates the distance and direction from own ship to a geographical site expressed by the extracted latitude/longitude information, and outputs information on at least the calculated distance and the extracted latitude/longitude information.