Abstract: A chain lock has a chain engagement portion including a slot configured to allow a link of the chain to pass therethrough with the chain engagement portion engaging an adjacent link of the chain. The chain lock has a pivoting member with a proximal and distal end. The pivoting member pivots about the proximal end such that the distal end is movable between a first position in which the pivoting member distal end is spaced from the slot in a manner to allow a chain to be received in and removed from the slot and a second position in which the pivoting member distal end extends across the slot to prevent the chain from being received in and removed from the slot. The pivoting member has a pivot axis spaced from and parallel to the chain engagement portion.

Abstract: The method improves the signal-to-clutter ratio of an airborne earth penetrating radar for distinguishing subsurface objects from surface clutter or above-ground objects. The method relies on the dispersive response of the signals returned from an subsurface object to distinguish these subsurface signals from the non-dispersive response signals returned by surface clutter. The electromagnetic response from a subsurface object is spread out over time in comparison to the response from surface clutter. A correlation coincidence detection methodology discriminates surface clutter based on the temporal persistence of a subsurface object. The correlation procedure produces a sequence of values which are used as the basis for detection. If the radar pulses detect a subsurface object, the sequence of values persists beyond the interval of integration containing the clutter response.