GPR vector imaging for Archaeological survey

GPR surveys over sites with strong topography can greatly affect the direction of the radar beam that is transmitted into the ground. On some sites with severe topography, the antenna can be at angles approaching 30 degrees or more with the horizontal. At deeper recorded time windows, the main part of the beam can be imaging the subsurface ground several meters away from actual position as deeper reflections are returned to the antenna. Most survey operations over sites with topography do not correct for the tilt of the antenna. For sites with significant topography, imagery uncorrected for tilt can distort the geometry of reflections deeper in the time slice dataset. The yaw, pitch and roll are conveniently referred to as the tilt of the antenna for simplicity. Early attempts to correct for tilt were made almost a decade ago [1,2] but today are still not being regularly discussed or incorporated in any known data analysis before or since. Without antenna tilt being compensated for, the size of subsurface features can be drastically over or underestimated on uncorrected radar profiles. Correcting for tilt in 3 dimensions where the yaw, pitch and roll of the surveying antenna is compensated for in GPR datasets, is presented for a survey made at Saitobaru Kofun Burial Mound #202 located in Miyazaki Prefecture, Japan.