Departing from a methodology that was considered standard operating procedure is never an easy step to take. The main values of interest to the integrity of a seismic survey will be the Aerial/Ground Calibration Point ties (AGCP). An AGCP is a GNSS RTK quality observation of an aerial target on the ground. AGCP ties are values depicting the relative accuracy of the dataset when referenced to and processed off of RTK surveyed ground control targets (AGCPs). The chart below is a control point tie report from a 500-acre project that was captured with the use of 7 AGCPs. Due to the heavily forested location, more AGCPs were used to ensure that plenty of options were abound
while processing and geo- referencing the flights. The mean delta divergences (XY) from the RTK coordinates were under 1 centimeter and the largest elevation delta was less than 2.5 centimeters (< 1 inch). Human error can be introduced during the “picking” of the control points during processing. The most error introduced in the flight below was still under 5.5 centimeters horizontally (~2 inches).