US Air Force (USAF) STAFF Sergeant (SSGT) Christopher Hughes (front) and USAF SENIOR AIRMAN (SRA) Michael Galang, Bio-Environmental Engineers, 30th Medical Group (MG), use a Narda Probe to perform a radio frequency survey on a radar dish providing satellite telemetry, tracking, and command, of the satellite control network from the Vandenberg Tracking Station, Vandenberg Air Force Base (AFB), California (CA)