Full exploitation is costly, requires extensive support facilities, and may require near continu-ous coverage and extensive coordination among participants Source locations may be imprecise A3.4. The conflict in Southeast Asia brought about the development and use of this unique intelli-gence source. Seismic sensors detect or measure seismic disturbances generated by moving vehicles or personnel. Magnetic sensors detect changes in the ambient magnetic field caused by the movement or presence of metallic objects. Their range is extremely short, but they can be used to cue other, higher resolution sensors and to identify or classify targets.
Electromagnetic sensors detect target emitted electromagnetic radiation.
Have a nearly instantaneous intelligence capability Cue other sensors A3.4.3. Unattended sea sensors can provide valuable support to tactical air forces conducting sea interdiction and reconnaissance or surveillance operations. Potential sea sensor roles, advantages, and limitations are generally the same as those for unattended ground sensors. Collectively, imagery is the representation of objects reproduced optically or electroni-cally on film, electronic display devices, or other media. While each sensor operates at different spectrum frequencies and each type of imagery has distinctive character-istics, the advantages and limitations of each are similar.