Ground-penetrating radar device and method for same

An underground exploration method executed by an underground radar device including a transmission array antenna and a reception array antenna, the method comprising exploring underground by changing intervals between antenna elements of the transmission array antenna and the reception array antenna using a position variable mechanism while keeping all the intervals equal,

• wherein the position variable mechanism comprises:
• a drive unit capable of changing an interval between a first pivot and a second pivot that are vertically arranged;
• a plurality of crossbars which have one ends thereof connected to the first pivot and the second pivot to form a V-shape and an inverted V-shape, in which the one ends are respectively connected to another end forming the V-shape and another end forming the inverted V-shape, and which constitute an expandable link expanding and contracting by changing inclination angles of the V-shape and the inverted V-shape in conformity with the interval;
• and
• a plurality of link sections that couple intersection portions where the crossbars intersect, and two of the crossbars at each portion forming a bottom of the V-shape and a crest of the inverted V-shape so as to allow the inclination angles of the V-shape and the inverted V-shape to be changed, and
• wherein the antenna elements are arranged at the respective link sections.