ninhydrinal

You're missing the problem completely here. When the altitude difference is 0, I'm on target. The second I go up by 11 altitude, I'm off target by almost 2 degrees. That would mean that in the equation, something with y is causing that deviation. I have no clue why though and that's what I'm trying to figure out.

Changing it from 9.80665 to 9.81 only changes the angle by 0.02 at 13.5km.

I'm not at home right now so I can't do any further tests but I will be when I get back. It's not negligible at short ranges. In my scenario, being off by more than 200 meters can result in friendlies being shelled. In short ranges, that I've zeroed in on, the dispersion hasn't been more than 100 meters which is fine on target. I've done tests from 1.2km to just over 9km, while on flat land, and it's consistently off by +- 3. I'll expand on this later with more images/math when I can. I am using a spotter but this should still be able to get me on a 100 by 100 meter gridsquare with the first round. Edit: Here's what I mean. I took the same target, at 3 elevation, and ranged it from similar areas but at a slightly different elevation. Same Elevation: http://imgur.com/a/RF9E8 +11 Elevation: http://imgur.com/a/CDpnd This is eye opening to me because once I raise my elevation by 11, my artillery elevation is thrown off by 1.68 degrees. Edit 2: So I did this test again at an elevation 90m, aiming at the same target, and my artillery elevation is off by 1.74 degrees this time. Such a huge difference in elevation but it didn't throw it off much further than when I was only 10m higher than the target.

Yeah, I thought the issue was going to be drag as well but it threw me off when I found out that the airFriction to the shells is 0. Something has to have changed since SMPCrafters released that video. I'm placing my scorcher in almost the exact same location but shooting at a different target. He was able to get an angle that was only 0.19 off so the equation did work when he posted it. The formula is also a well known one for projectiles. https://en.wikipedia.org/wiki/Trajectory_of_a_projectile#Angle_required_to_hit_coordinate_.28x.2Cy.29 I'm taking a look at your spreadsheet and it still seems to be off. I placed 2 scorchers apart from each other on the salt flats, both at 3 elevation, just 1280m apart. The in game artillery elevation control tells me I should be aiming at 72.47 but when I plug the range into your sheet, it says to be aiming at 73.99. Something still seems to be off.

So I've been practicing firing mobile artillery without the use of the artillery computer but I've hit a weird issue. No matter how many times I run the equation, the elevation is always off by +- 3 degrees. I've been trying to figure this out all night with very little to show for it. Does anyone know why this happens? I'm using the worksheet from this video: https://www.youtube.com/watch?v=A4SPene9Yxw And I'm also using this spreadsheet: https://docs.google.com/spreadsheets/d/1q4PWQ4b6azx7YAKrRErsdKEiaYvuJzp0Who7V0batAc/edit?pageId=116206726297015043606#gid=0 Here's an album showing my battery, target, and the line of sight targeting, which shows what the elevation should be: http://imgur.com/a/jYKZG When I plug those numbers into the equation/spreadsheet I get this: https://i.imgur.com/1nnLnzu.png The elevation that it tells me to range for in this case is a complete degree off. If I fire here, my rounds will be landing short of the target. In this particular instance my forward observer could tell me that and I could adjust accordingly. However on most targets that difference is up to 3 degrees off so when firing long distance, my rounds will be landing far away from my target and I end up hitting friendlies.