Abstract: A mobile radar system including Electronic Support Measures (ESM) which is adapted to detect and decode Identify Friend or Foe (IFF) signals. The system includes means for decoding or decrypting received IFF signals. The system uses an Electronic Counter Measure (ECM) transmitter which is adapted to transmit IFF response and interrogation signals. The IFF signals to be transmitted can be encrypted. Integrating IFF means into the ESM and ECM components results in mass and volume savings due to shared use of the transmitting and receiving resources. As the IFF signals are transmitted using ESM antennas, they can be directed towards a particular aircraft, thereby reducing spurious transmissions.