Method and Apparatus of Physically Moving a Portable Unit to View an Image of a Stationary Map

A method of moving a portable unit to present a new portion of a stationary background image on a screen of the portable unit comprising the steps of:

• displaying a first image on the screen of the portable unit matched and superimposed to a corresponding portion of a stationary background image;
• mapping a first point of the first image located in a center of the screen of the portable unit to a corresponding reference point in the stationary background image;
• determining a first vector between the center of the screen of the portable unit and the corresponding reference point in the stationary background image;
• moving the portable unit along at least one of the orientations of the first vector;
• and
• presenting a new location in the new portion of the stationary background image on the screen of the portable unit.