Everything you need to know about... Telemetry!

Hello tankers (yes, aviators don’t really need this introduction).

Today we’re going to look at how to find out how far you are from the area you’re watching or your target.

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To begin with, we’re going to look at THE command used to measure distance with in-game equipment. Then we’ll go from the least reliable method to the most reliable.

-1) The shooter’s estimation

• Measurement time: 3.5s
• Max distance: 1200m
• Measurement accuracy: 5m to 100m depending on the distance measured.

The first method you’ll use in the game to measure a distance will be to call on the skill of your gunner. This method is the least effective because it takes time, is subject to measurement error and has a maximum distance of 1200m. Which, you’ll tell me, is enough for low BR confrontations where engagement distances rarely exceed 1000m (most often, it will be 500m).

What’s more, unlike other methods, the accuracy and maximum distance are affected by the skills of the crew:

• Vehicle control (basic, expert or ace)
• Telemetry skill (shooter)
• Charism (commander)

How does it work in real life?

Well, not quite the same as in the game, because in real life you spend all your time estimating distances, even subconsciously. You’ll also use distance markers that you know (like the length of a football pitch) to estimate a distance.

How do you know the maximum distance the gunner can estimate? in the crew card:

Let’s look at a few examples of possible measures:

Measurement within the gunner’s range:

Measurements outside the gunner’s range. Note the difference in maximum distance depending on the crew’s skills:

• Measurement time: variable according to your own skill.
• Max distance: variable depending on the max distance set by the sight modeller. But often much more than the 1200m estimated by the gunner.
• Measurement accuracy: Varies according to your knowledge of target dimensions and measured distance and the accuracy of the stadimetric scale made by the modeller.

This is a method of estimating distances by comparing an object of known size (in this case a tank) with a scale contained in the instrument. The stadimeter is the device inside a telescope that is compared with the object under observation.

How does it work in real life? Well, like in the game.

This method is not included in the game, but sight modellers have worked on rendering stadimetric distance measurement on custom sights. Having a custom sight with these measurement scales makes up for the absence of a rangefinder on tanks that can shoot far (beyond 1200m, like German tanks for example).

Not necessarily as accurate as the estimate made by the gunner in his field of expertise, it does however cover a much greater distance (3 to 4000m) and depends above all on YOUR ability to measure the distance of the target.

There are several types of stadimetric scale: VERTICAL which uses the HEIGHT of the target and HORIZONTAL which uses the WIDTH or LENGTH of the target.

Some are integrated into the sighting axis and all you have to do is move the sight up until the marks on the scale are aligned with the target to get the distance measurement and shooting correction at the same time. Others are separate from the rear sight and require you to move your optics to take the measurement before adjusting the rear sight accordingly. These are slower than the integrated scale on the rear sight, but still allow you to keep your aiming area clear and see your targets better.

!!! WARNING!!! This method, although more efficient to measure a distance, requires you to know the dimensions of the machine you are trying to measure. Most stadimetric scales are based on the following dimensions: Width: 3m, Length (of the body): 6m, Height: 2.5m. The distance measured can therefore vary depending on the dimensions of the targets. For example, if you know that the hull of a tank is 7m long and you measure 400m, it will actually be a little further.

Here are some examples of stadimetric distance measurements:

!!! WARNING!!! With this method, be careful not to make a measurement error by measuring the entire target vehicle, but ONLY the corresponding dimension (width or length). Since vertical stadimetry only uses the height of the tank, there is less risk of error (see spoiler below).

Here are other forms of stadimetric scales:

Somua SM, fictional custom sights:

T-80U, Realistic custom sight:

A little fun fact before moving on to the rest of the presentation: The emergency optics on the most modern vehicles still include sadimetric scales for measuring distance in the event that the telemetry and/or fire control equipment is out of order.

Here is an example of the Leclerc’s optics: the upper part is a lens that slides into the gunner’s field of vision if necessary.

-3) Optical Rangefinders (abbreviated OR)

• Measurement time: 3s to 1.3s depending on the era of the vehicle
• Max distance: 2000m to 5000m depending on the era of the vehicle
• Measurement accuracy: 50m

ORs are no longer dependent on the skills of the crew to carry out the measurement. While the accuracy and measurable distance vary according to the era of the rangefinder, ORs can measure far more accurately than the gunner can estimate. The capabilities of a given rangefinder cannot be modified.

Easy to use, they have the advantage of being undetectable, even though they are rarely used at very high BR.

How does it work in real life?

Most optical rangefinders are “coincidence” rangefinders. In other words, the operator looks into the device and sees 2 distinct images. He manoeuvres the rangefinder until the two images coincide. A marker then indicates the distance to the target. Requiring a minimum width to be effective, these rangefinders are often mounted on fairly wide turrets and form ‘bumps’ around their optics.

Although they can be used on vehicles whose armament can be stabilised, OR have no action on the gun (unlike the equipment we will see in the next chapter).

An OR can also be used to measure the range of flying machines. However, if the target is moving, the distance measured may be quite different from the target’s actual distance at the time you get the information.

How can I tell if a vehicle is equipped with an optical rangefinder? By looking at the modifications:

-3) Laser Rangefinder (abbreviated LR)

• Measurement time: 0.6s
• Max distance: 10 000m (depending on equipment)
• Measurement accuracy: 1m

Laser Rangefinders (LR) are the latest generation of distance-measuring instruments, making it possible to measure faster, more accurately and further than any other method to date.

So, how does this diablery work in real life?
Very simply: a transmitter sends a laser beam towards the target, the beam is reflected by the target and travels back to the receiver in the tank. Knowing the speed of light and the time it took for the beam to make the round trip, we can deduce the distance. Although these lasers are invisible to our poor eyes, they can nevertheless seriously damage them if you look directly at the rangefinder’s laser emitter. Think about it when you see a modern steel monster.

Most often fitted to vehicles with stabilised weapons, ORs can be used to simulate some of the firing conduct in the game by automatically adjusting the gun’s elevation. In simulator games, or if you use the gunner optic in other game modes, the LRs also compensate for the horizontal offset of the gun relative to the optic. For the most advanced machines, the sequence is very simple: Aim, Telemeter, Shoot.

!!! WARNING!!! With the gunner’s optic or the tank commander sight, the minimum correction distance for the gun is 200m . If you telemeter a closer target, the gun will be set for 200m and you will then have an offset varying according to the distance (the closer the target, the greater the offset)..

How do you know if a vehicle has a laser rangefinder? Again, in the modifications:

!!! WARNING !!! if you make an invalid measurement (on a smoke screen or in the sky) the gun setting will not be changed and will remain on the last value set.

Thanks to the speed of the measurement, anti-aircraft gunfire is also made easier, especially on helicopters that don’t move too much.

Well, you still have to aim much further forward if you want to hit the target

Finally, some vehicles, as well as being fitted with a LR, have another piece of equipment: a Laser Warning System (LWS) . This system is very useful for knowing if someone is out to get you. An LWS is activated when a laser ping is received by the device, a bit like a RWR for radar, and warns you that someone has just measured the distance separating you from them or that a missile (laser-guided, that is) is approaching you.