Does dynamic lead calculate range?

[raygun]

Hello there.

This is a newbie question: For the leopard 2A4, while tracking a target, I only need to lase, get the range, then remove finger and press & hold dynamic lead (while still tracking) right?

Does the dynamic lead auto calculate the distance as target changes distance? Or do I need to re-lase if target change direction (instead of moving left or right), and is moving away or towards me?

Thanks for taking the time to reply.

cheers

[Trekker]

The lead only calculated how the turret moves, not how the target moves. So if the target is coming at you aim low, away from you aim high.

I add lead then right before i fire i lase, works for me.

[RecceDG]

Well, dynamic lead calculates the amout of angular lead as a function of the current distance entered into the ballistic computer - and if the laser is working, a lase will automatically enter the range to target into the computer for you (at least on Leo)

The computer gets its lead info in terms of change of traverse in mils per unit time, so it needs the distance to target in order to complete the equation.

Consider that a slew rate of (say) 5 mils/sec is a target speed of roughly 500 m/second at 1000m, but 1500 m/sec at 3000m - you need a different amount of lead to hit those two targets, even though the turret traverse rate is the same for both of them.

Ideally, you want to lase and fire as close to simultaniously as the system will allow.

But no, the computer does not look at rate of change of gun elevation (to determine closing/extension rate) the same way it looks at angular traverse change to determine lead. So depending on the time of flight of the round, the speed of the target, your speed, the ballistic path of the round, and the aspect angle of the target's motion vector relative to yours, dynamic lead alone may not be enough to hit the target.

Happily, at the speeds (both of the vehicles and of the rounds) distances, and given the sizes of typical targets (and especially with sabot which has a very flat trajectory and a very high flight speed) those changes in distance usually wind up as a wash. Aim at the lower edge of a target coming toward you, or the top edge of a target going away from you, and that almost always takes the changing range out of the picture.

"Perfect is the enemy of good enough".

DG

[Trekker]

eem yea, what Recce said. :)

[raygun]

Hey thanks for replying guys.

I was under the impression that we MUST lase to get range before engaging lead, am I right that we can actually engage lead, then lase & fire?

cheers

[Ssnake]

Yes, you can. In the meantime the fire control system will work with the last know range. As the trigger is being blocked if the gun position is not in alignment with the line of sight (well, technically, within the acceptable error margins of the nominal gun position, which is a function of superelevation angle, hull, and turret position - the so-called "coincidence windows"), you can lase and pull the trigger and the gun won't fire until the necessary corrections have been applied; that is so fast however that you will hardly ever notice.

[raygun]

Thanks for your reply Ssnake. Its all clear now.

cheers