G PHYSICS
G01 MEASURING; TESTING
G01S RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
G01S7/00 Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
G01S7/02 of systems according to group G01S13/00
G01S7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver