RWRs developed since the 1960s, such as the AN/APR-25 (A-4E), AN/ALR-46 (F-4E/Kurnass), AN/ALR-56(F-16) etc, has Handoff mode in the real life.
This mode allows a pilot to select a specific radar emitter as a priority threat. Once selected, the RWR plays back the unique audio signature created by that radar’s pulse repetition frequency (PRF). Crucially, this audio signature changes depending on both the type of emitter and its operational status.
For instance, the tone of SA-2 “Guideline” SAM is distinct from Roland SAMs one. This enables experienced pilots to identify threats by ear, without having to look down at RWR display. Furthermore, a sudden change in the tone can signal a critical status update, such as the radar switching to a continuous wave (CW) signal for active missile guidance.
In one of the most famous pieces of HUD footage from Operation Desert Storm in 1991, an F-16C pilot evades x6 SA-2 and SA-6 SAMs simultaneously, identifying which threats were searching, locking on, or launching by listening to their distinct audio cues via handoff mode.
If RWR handoff is implemented in the game, you could identify threats by their audio cues even if your aircraft’s RWR is too primitive to display specific threat types in some cases. This would allow you to understand what kind of threat is targeting you and how to evade it.
I know it’s difficult to implement, but if current RWR had more functionality, it would be significantly more effective in markerless modes such as Ground RB and Air/Ground SB.
The APR-25 possesses the capability to intercept three distinct radar bands: E, G, and I.
The early and late models of the SA-2 Guideline utilized the E band, while the mid-production model operated on the G band. The SA-3 Goa, conversely, employs the I band.
Mid and late model SA-2s were equipped with two additional antennas specifically designed to maintain a narrow, non-sweeping beam for tracking maneuvering targets. This functionality is what generates the continuous tone that an operator hears. During normal operation, the Fan Song radar, whether via its dish antenna or trough waveguides, performs a pattern sweep 16 times per second, which produces a discontinuous noise.
Another signal the APR-25 is capable of detecting is the C band, which is used for the missile’s guidance system. Therefore, the reception of a C band signal indicates that a missile is likely already in flight. However, it is important to note that signals may also be transmitted for deception purposes. The detection capabilities of this device are fundamentally limited to the E, G, and I bands.
