Here is a definition of Mortar Locating Radar (MLR) I located at a website dedicated to the subject.
A Mortar Locating Radar provides quick identification to pinpoint enemy mortar positions in map co-ordinates, enabling artillery units to launch counter attacks. The system electronically, scans the horizon over a given sector several times a second, intercepting and automatically tracking hostile projectiles, then computing back along the trajectory to the origin. The co-ordinates and altitude of the weapon are then presented to the operator.
There are eighteen governments, around the world, whose armies own such equipment.
We also have a system called Weapon Locating Radar (WLR)
These are primarily used to detect and locate enemy artillery units by tracking the trajectory of incoming rounds. They can also provide fire correction of friendly artillery units. WLRs usually can also track mortar shells and unguided rockets. Some WLRs also have limited missile tracking and Air Defence capabilities.
AN/TPQ-36 Firefinder is a mobile radar system manufactured by Hughes Aircraft (later acquired by Raytheon). The system is a “weapon-locating radar”, designed to detect and track incoming artillery and rocket fire to determine the point of origin for counter-battery fire.
AN/TPQ-37:Firefinder radar(United States):The system has a reported range of up to 50 kilometres.
ARTHUR: “Artillery Hunting Radar”(Sweden):The System can detect incoming artillery rounds at 40 kilometre distance.
The MAMBA:Weapon Locating Radar(UK):The system has a reported range of up to 30 kilometres.
SLC-2 Radar:WLR,Firefinder radar(Chinese):The system has a reported range of up to 50 kilometres, SLC-2 radar can also be used to detect and track low flying targets such as light aircraft, helicopters and RPVs.
Type 704 Radar:Firefinder radar(Chinese):The system has a reported range of up to 50 kilometres(Copy of US AN/TPQ-37).
BL904:WLR,Firefinder radar(Chinese):The system is newly introduced so its capabilities are not known yet.
The problem with these tools is they’re automatic. When a mortar is launched, all these tools do is to provide a map reference of where the mortar is coming from. If, for example, someone from Army A fires a mortar at a position on Army B, Army B can retaliate automatically with Artillery at the position provided, someone at the position of Army A will then get hurt. Pretty damn quickly.
The real problem is if Army A fires their mortar in the middle of a sensitive area with civilians present.
There are two questions to ask ourselves here.
Has any government who holds a licence to use these tools ever sold “Mortar or Weapon Locating Radar” to any “third party” countries who don’t hold such licences?
Do any armies or military groups ever fire mortars at troops from the locations of schools or other sensitive locations?
This is an article on “Mortar Locating Radar” and “Weapon-Locating Radar”.