“…These reconnaissance methods include airborne techniques, such as remote sensing with stereo air photography, satellite imagery including both visible and near-infrared systems (Pieters and Englert, 1993;Friedman et al, 1994), aeromagnetic surveys and, more recently, airborne gravity (Saad, 1993;Kuuskraa et al, 1996;Pearson and Inden, 1997). However, the cost of seismic methods, exacerbated for deep exploration, calls for reconnaissance methods to identify the most promising regions for a seismic survey.…”