What does ARDF stand for?

Airborne Radiation Detection and Fixing - Military

Airborne Radio Direction Finding (AFM)

Air Reconnaissance Detection Force (CINC)

Alexandra Rose Day Fund (SAUO)

Amateur Radio Direction Finding

Applications Research and Defense Fund (DNAB)

Association Reunion Departement Francais - Association for Reunion as a French Department - Political party (PPW)

Automatic Radio Direction Finding (MLEX)