frequency intelligence

pulse repetition frequency (PRF) / pulse-repetition frequency

Secret Intelligence Service (SIS) / Military Intelligence, Section 6 (MI6)

tactical intelligence / combat intelligence

undeclared member of the intelligence or counter-intelligence agencies

Defence intelligence of Ukraine (DIU) / Main Directorate of Intelligence of the MoD of Ukraine

common frequency

doppler frequency shift

fixed frequency channel

frequency

frequency and directional chart

frequency band

frequency modulated (FM)

frequency modulation (FM)

frequency range (band)

frequency response

frequency, intensity, time, type (FITT)

frequency-hopping mode

guarded frequency

high frequency (HF)

high frequency direction finder

high frequency over-the-horizon (HF OTH) radar

high-frequency 'X-band' system

intermediate frequency

low frequency (LF)

operating frequency

operational frequency

preset frequency

protected frequency

radio frequency (RF)

radio frequency explosive device

radio frequency identification (RFID)

radio frequency sensor