Firing hundreds of KM in some cases, accurate within a few hundred feet? How is that possible? And how do they “dial in” new coordinates exactly? It all seems like magic to me

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So artillery in the modern age is directed at targets by artillery observers or forward observers, sometimes FISTers: soldiers that utilize a menagerie of methods to watch over a battlefield and give the coordinates of targets to the artillery pieces firing. This can be done either by sending coordinates to a fires direction center, a headquarters where battlefield intel is needed in conjunction with firing artillery, or straight to the artillery pieces themselves.

Lasers, GPS, maps, compasses, binoculars, and drones among many methods to find the coordinates for a target. What’s called a fire mission is conducted where a round is dropped at initial coordinates given to artillery pieces and then by direction from the observer, the guns adjust and fire until rounds hit target. If you’ve ever heard ‘fire for effect’, that is what is called in for the typical bombardment of accurate rounds on target. Of course, if you’re aided by GPS, and computers and such, the initial fire mission might just be a fire for effect without the need to adjust rounds. Communication between entities is the key to accurate artillery fire.

Lots of work ahead of time

Someone at the test range has to nail down the parameters of the gun so they know how fast the shell comes out and how it slows with distance

Then someone has to do the hard math to figure out where each possible combination of angles and powders will land. This is just a projectile motion calculation from a physics class but with the added joy of air resistance.

The first programmable electronic general purpose digital computer was ENIAC and its very first task was calculating artillery firing tables. This takes data about angle of the gun, weight of the projectile, temperature of the air, amount of powder, temperature of powder, and does all the calculations in advance to say where a shell will land with given conditions. The end result is basically a book of tables

Once all the hard math is done, the artillery man just needs to know where he is relative to the target (distance, angle, and height), what the temperatures are, and what the wind is and the book says “set to 37.3 degrees elevation with 4 charges”

Some newer artillery pieces have computers on them which can do the calculations on the fly based off a target location that’s selected and the known position of the artillery. They’re still doing the same calculations as ENIAC but they can do it in milliseconds instead of hours

Lot of math, the way they ‘dial’ it in is by firing 1 round waiting for it to hit then an observer sends instructions on how far off they were and the next shot is shifted accordingly.

Basically, everything above a range of 50km is smart ammunition of either 155mm artillery and larger shells or rocket artillery. Both aren’t just bombs that you fire and then drop out of the sky. They are actually small computers with an array of sensors and steering capabilities.

Rudamentally similar to a car’s GPS such ammunition knows where it is during flight and can just extrapolate its flight path based on physics formulas. Then it uses fins, gimbal or similar methods to adjust its path to steer it to the GPS coordinates uploaded. The newest ones have an accuracy of feet not hundreds of feet.

Relevant [video](https://www.youtube.com/watch?v=bZe5J8SVCYQ) on how rockets know their position.

The most basic answer is math. The science of ballistics is all just math. The weight of the projectile, the angle it’s fired at, the charge of the propellant, the length of the barrel, gravity, wind resistance, temperature, the curvature of the earth, humidity, moon phase, (maybe not moon phase). All these things are factors that can be put in a calculation to accurately predict where that projectile will hit.

The oldest forms of artillery like trebuchets and stuff were just tested a lot and they worked out how far they fired with all the variables. Modern guns are treated the same way but modeling that is a lot easier with computers now.