Im not familiar with those things... but I recall Balad Airbase had counter mortars that could return fire as rounds were incoming. Problem was the enemy would hang rounds with Ice cube sting fuses.... went the ice melted the rounds would fire.... and they were long gone before we returned fire.
LCMR is a low cost CMR that can be mounted anywhere, very small. Round pill box looking things you’d see atop a vehicle of compound high point. TPQ53 is a bigger, better truck mounted version with greater range and rocket/artillery fire detections. CRAM would be something like a Phalanx gun fire system connected to either of these, IIRC.
They also used to use the ‘bent-fin’ technique on the rounds. Gives the round a nonstandard parabolic trajectory that makes source detection hard.
In AFG they used washing machine/dryer timers.