When I was at Ft. Jackson, MLRS hadn't been invented yet, and there were no Active Duty assets other than training support as fas I as I know.
The MLRS Battalion we had in the Michigan Army Guard (182nd FA/MLRS, 177thMP BDE) may have had a Target Acquisition Battery, but I never heard of it. I was with the Direct Support Unit and we called ourselves the "inflight missile mechanics" or "rocket docs" and only worried about the launcher getting the rounds downrange. Never wondered how they decided where the target was.
EDIT:
IIRC, TRADOC is actually HQd at Ft. Jackson and so all of the pubs and doctrine statements from TRADOC are credited with being written there. MLRS is actually considered Field Artillery (FA) and unless they've stuck a new unit at Jackson, Artillery comes out of Ft. Sill, OK.