A system and method of security monitoring is disclosed. The wideband intelligent jamming control apparatus includes a signal detection terminal for detecting and analyzing wideband frequency signals in real time, and transmitting a jamming command and jamming signal specification information if a corresponding wideband frequency signal is determined to be an unauthorized threat signal. The method requires only one high precision measurement, which is the depth of the two calibration points from a reference plane. The sieve and pan assemblies are mounted and driven in such a manner that the feed stroke of each assembly is in the same direction as its direction of conveyance, so as to maximize their ability to deliver materials in the intended direction.