Still Sosna seems like an unusual weapon for a helicopter...what is at used for ? other attacking other helicopters?
Would suspect drones and cruise missiles if they are adding a nose mounted radar array... it would be an interesting short range air patrol platform able to fly around and engage light aircraft... the SOSNA missiles are rather fast and with the solid fuelled rocket motors they should be able to rapidly climb to engage targets at higher altitudes than most MANPADS can. It also does not require a good IR or radar signature to engage.
Would be ideal for use against all sorts of air threats and targets... and soft ground based targets too.
Which stuff are in the launcher ?
What I mean is a comparison with Javelin... it has a thermal imager in it so when you launch you can walk away. But the thermal sight inside the missile is destroyed with normal use and is very expensive.
The Sosna looks back at the launch platform and positions itself in a laser beam... because the sensor in the missile is looking directly into the laser source rather than a reflection it means the laser can be thousands of times less powerful... you can compare with a torch... a small light torch might light up an area of 20-30m, so if you were a missile using light from the torch as guidance you wont be able to be used against targets more than 30m away without a much brighter torch.
If however you took the light sensor off the front of the torch and pointed it backwards at the torch, then you could probably see that torch for 10-20km... it doesn't need to light up the target to make the target visible... you just need to see the beam and your position in that beam.
SOSNA uses a coded laser beam like aircraft on an aircraft carrier use a mirror and lights to land. The glide slope to land is fixed and is indicated by mirrors and lights... if you are on the correct glide slope you see green lights... if you are too low you see red lights and therefore know you need to climb... if you are too high you see yellow or blue lights and know you need to get lower to land safely.
SOSNA and Kornet and Vikhr are the same, but they are looking back at a laser and determining where they are in the beam in a similar way... they manouver themselves in to the centre of the beam.
But all the expensive high tech detection and tracking stuff is in the launch platform... whether that be a SOSNA vehicle or Hind helicopter or a portable Kornet launcher.
The launcher can be expensive with long range optics and EOs plus all weather day night optics like thermal sights, as well as autotrackers and the like to enable point targets to be engaged out to 10-12km distance day or night, but the missiles are cheap and simple...