Rapier tracking, launching & guiding even though tracker destroyed (Modelled as radar not optical).

[Weta43]

Rapier is an optically guided system that's radar simply cues an operator to a target area:

"Rapier is a surface-to-air missile developed for the British Army to replace their towed Bofors 40/L70 anti-aircraft guns. The system is unusual as it uses a manual optical guidance system, sending guidance commands to the missile in flight over a radio link. This results in a high level of accuracy, therefore a large warhead is not required."

The available units in DCS are the optical tracker, aquisition radar and launcher.

In DCS the system is modelled as if it were a radar SAM, and will launch even if the tracker is destroyed.

Modelling it as a radar system is OK, but it should stop launching if it has no available tracker.

See debrief snip for timing, track attached

(Sh*t flying was trying to get the Kh-25 working while discovering my control mappings were all mixed up)

Guide after guidace gone 2.trk

[Northstar98]

This is likely correct as-is.

Rapier FSA w/ Blindfire provides for 2 guidance modes:

• Optical Guidance Mode - uses the optical tracker to track the target manually and to track the missile via a TV system (SACLOS).
• Blindfire Guidance Mode - uses Blindfire to automatically track the target and missile (ACLOS).

The whole idea behind Blindfire is that it enables the system to fire when the optical tracker is blind and can't see the target (hence the name).

You can also see that Blindfire includes a TV system, which is mounted coaxially to the antenna. A BAe Dynamics brochure on Rapier FSA describes it as a "gathering unit", which implies it's for missile tracking. EDIT: Also, having the optical tracker's TV system track the missile and Blindfire track the target introduces further complexity (though not insurmountable as after all, Nike Hercules does a similar thing (at least in principle).

The launcher also contains the computer for generating steering commands based on data from either the optical tracker or Blindfire and includes the J-band command antenna which transmits steering commands to the missile.

Based on that - I'm not sure where the optical tracker is involved when the system is using Blindfire, if anywhere. 

On 7/26/2025 at 4:52 AM, Weta43 said:

The available units in DCS are the optical tracker, aquisition radar and launcher.

Blindfire is not an acquisition radar - it's a fire-control radar.

The acquisition radar, which I've only ever seen referred to as "Rapier Surveillance Radar" (not to be confused with the later Dagger system used in Rapier FSC) is under the cylindrical radome on the launcher (and also includes an IFF interrogator).

Edited Sunday at 11:27 AM by Northstar98

[Weta43]

More reading

You're right, the Blindfire can guide the missile.

When introduced (in 1971) Rapier was optical guidance only, with the search radar under the dome only providing cuing (the dish on the front of the launcher is just coms).

The Blindfire radar was introduced in 1979 & that can guide missiles, making it an all weather system.

I'll take out the radar, check it still guides, destroy the tracker, see if it still guides...

[Northstar98]

Yeah looks like it still guides even when there's nothing available to provide said guidance.

If you set up your Rapier unit to only have the optical tracker or to only have Blindfire (less realistic set up but is a viable way of forcing Blindfire guidance mode) if after the missile is fired the optical tracker/Blindfire is disabled/destroyed or is set to stop emitting.

In the tracks below the missile remains in guided flight despite the optical tracker/Blindfire being disabled, destroyed or Blindfire set to stop transmitting.

As mentioned above, Rapier is a command-guided system, requiring either the optical tracker or Blindfire to track the target and the missile - if neither are operational, the missile should stop being guided.

Spoiler

As an aside:

• The missile seems reliably inaccurate, even against slow moving targets which aren't manoeuvring - it seems that the LOS the missile should be guided along isn't properly aimed - in most of these tracks the missile flew underneath the target.
• The plume of the missile is misaligned

RapierGuidanceWhenOTDestroyed.trk RapierGuidanceWhenBlindfireAIOff.trk RapierGuidanceWhenBlindfireDestroyed.trk RapierGuidanceWhenBlindfireNotTransmitting.trk RapierGuidanceWhenOTAIOff.trk

Edited Monday at 11:48 AM by Northstar98