GROUND-PENETRATING RADAR ANTENNAE FREQUENCIES AND TRANSMITTER POWERS COMPARED FOR PENETRATION DEPTH, RESOLUTION AND REFLECTION CONTINUITY

Twelve ground penetrating radar (GPR) experiments were conducted on the modern, wave-influenced William River delta, on the southern shore of Lake Athabasca in northern Saskatchewan, Canada. The delta is a well-sorted, quartzose-rich, clean, sand-dominated, water-saturated geomorphic feature which provided an ideal site to test GPR. Penetration depths, resolution and continuity of reflections were compared for different antennae frequencies (25, 50, 100, 200 MHz) and transmitter powers (pulser voltage: 400 V, 1000 V). The data show significant variations in vertical resolution from 0.15 m to 0.76 m (200-25 MHz), depth of penetration from 14 m-28 m (200-25 MHz), and continuity of reflections. Increasing the transmitter power from 400 V to 1000 V increases the depth of penetration by 5 to 14% and improves the continuity of reflections with little effect on the resolution.