Viviane sight

[MBot]

How is the Viviane sight able to stabilize on a point on the ground without having any information on its own movement? The Gazelle doesn't have GPS or INS, and even with the NADIR doppler system turned off, Vivane is able to track a point on the ground. I understand it is gyro stabilized but in order to be ground stabilized, it would have to have its own INS (which I doubt).

 

Usual tank thermal sights, which are very similar to Viviane, are usually also just gyro stabilized and not ground stabilized (see Steel Beasts). I have the suspicion that Viviane shouldn't actually be ground stabilized. Does anyone have any information on how the system works in real life?

[Flagrum]

Why wouldn't gyro stabilization not suffice? The sight points at an horizontal and vertical angle somewhere in space and is kept in that attitude by the gyros. What else would be needed?

[some1]

If you're stationary, the gyro stabilisation would suffice. But if you are moving, then in order to track a point on the ground you need to know your platform movement, either trough INS (accelerometers) GPS or doppler system. Or by locking onto a target through image acquisition and processing.

[Flagrum]

Hrm, ok, movement - the angles have to be adjusted accordingly, got it.

 

So, we have gyros and we have a doppler - that should do the trick then. Now we only have to try out, if the point the optics look at move according to the helo's movement if we disable the NADIR.

[some1]

Your question has been answered in the original post. Besides, the fact that you have those systems doesn't mean they are integrated and can work together. Like in Ka-50 where you have INS and ABRIS with GPS and they don't talk to each other at all.