Signal processing method, signal processing apparatus, signal processing system, and machine readable storage medium storing control information of signal processing apparatus

A signal processing apparatus comprising:

• a position information receiving unit to receive input geographical position information indicative of a current position from a positioning system;
• a display unit;
• and
• a data retrieving and control unit to obtain a specific boundary about a location from pre-set positional information, retrieve second data corresponding to first geographical position information different from the input geographical position information by automatically executing a link to a data source external to the signal processing apparatus and automatically displaying on the display unit the second data when the current position is within the specific boundary of the location, and automatically terminating display of the second data when the second data is currently being displayed on the display device upon the current position being no longer within the specific boundary of the location, such that the display of the second data on the display unit is provided only while the current position corresponding to the received input geographical position information is within the specific boundary of the location,
• wherein the pre-set positional information is included in a position information file, the position information file includes a description of the link, and the description of the link comprises a data format description which designates the external data source and a signal format of the second data from the external data source,
• in which the automatically executing the link to the external data source is based on a determination from the data format description whether linkage to the second data is possible.

A non-transitory recording medium recorded with a program executable by a computer, the program comprising:

• receiving input geographical position information indicative of a current position from a positioning system;
• retrieving first data based on the input geographical position information;
• displaying the first data;
• obtaining a specific boundary about a location from pre-set positional information;
• retrieving second data corresponding to first geographical position information different from the input geographical position information by automatically executing a link to an external data source and automatically causing display of the second data when the current position is within the specific boundary of the location;
• and
• automatically causing termination of display of the second data when the second data is currently being displayed upon the current position no longer within the specific boundary of the location, such that the display of the second data is provided only while the current position corresponding to the received input geographical position information is within the specific boundary of the location,
• wherein the pre-set positional information is included in a position information file, the position information file includes a description of the link, and the description of the link comprises a data format description which designates the external data source and a signal format of the second data from the external data source,
• in which the automatically executing the link to the external data source is based on a determination from the data format description whether linkage to the second data is possible.