Many techniques are in use or have been proposed for use as UXO detectors. The two most commonly employed technologies are electromagnetic induction detection and fluxgate magnetometry. While time- domain analysis of inductive signals has been suggested as a way to differentiate between hazardous and benign types of buried material, neither the induction detector nor the fluxgate magnetometer may be engineered to produce an image of potential UXO objects. The success of imaging technologies based on arrays of detectors like forward-looking infrared cameras for infrared target identification and charge-coupled device video cameras for consumer applications suggests that the sensor-array paradigm is worth exploring for UXO detection as well. Neither the electromagnetic induction nor fluxgate magnetometry methods is well-suited for incorporation into a detector array since these sensors are bulky in size. Newly developed GMR sensors, on the other hand, are now available now in integrated circuit form. These sensors are attractive for a variety of applications because of their high sensitivity (over ten times greater than Hall sensors), room-temperature operation (unlike SQUID magnetometers) and moderate cost (currently $5 each in small quantities).