Radar-set-max-range
From FreeSpace Wiki
Radar-set-max-range (Action operator) Sets the maximum radar range to the value of the argument. Entering -1 will reset maximum radar range to infinity. Takes 1 numeric argument: The maximum radar range.
Comments
Sets the maximum radar range for all ships in a mission, overriding any command line arguments affecting it. All radar ranges greater than the specified range are affected.