Author: Blakeace Author Website: http://www.zspecialunit.org Version: 1.3a Short description: Excel program to calculate firing solutions for indirect fire Date: 2009-08-30 08:15 Comments: (0) Rating:

Fire Control Calculator
by
Blake

Description:
Designed to be used with the Real Mortars mod, which I have nothing to do with. Thanks Jones for creating it.

Until something better comes along I created this excel program to calculate firing solutions for indirect fire, with the above artillery pieces. It doesn't use the spotter component, just the guns, as they have their elevation and bearing displayed.

Known issues:
If you start as a player on the gun you have to exit and re-enter the vechicle to get the display up.

How to use:
There is a tutorial in the armaholic forums, the link can be found at the end of the page info.

When you open it you need to enable macros as it uses user defined functions. It is set to manual update calculations so that it doesn't crunch away after every value is entered.

First you either need to have a second computer or switch between arma and excel on a single computer. Maybe somebody with scripting skills will decide to convert it into an arma script in the future?

First you need to set the grid scale for the island being used. Sara is 200m. it is the length of the smallest grid squares when zoomed right in while playing not editing. ie the square that denotes fa 33 on your gps will be 200x200. Other maps will differ.

Grid reference, your gps only gives a 2 figure reference for your lat and long. To be more accurate the calculator uses 3 figures. Meaning your reference should be accurate to about 20m.

Set gun grid reference. fa3 lat the number 3 is a value between 0-9. Estimated eg if the gun is in the center of the square it would fa5, if it is on the left edge it would be fa0 on the right edge fb0.
the same is done for the long. 335.

Set the altitude, use the contour lines to get this.

Now you are ready for a fire mission.

The Forward observer will initiate a fire mission.

Note you should have a pad and pen handy for both the FO and Battery HQ so that it is easier to read back and reduce errors.

All angles are in degrees as that is how the mod displays them, though convention in armed forces is mils.

eg:
Gunpowder(Battery) this is Birdnest (FO) fire mission over.

Birdnest this is Gunpowder fire mission out

birdnest
Grid Echo Charlie Five Three Two Four
Altitude Four Two
Direction Three One Zero
Troops in village.
Type of ammo Request (can be ignored in this mod HE only option)

This is read back enter this data into the calculator under the target section.

Grid and altitude define the taget location, direction defines the angle from the observer to the target. this is important when the FO calls for corrections.

Once the solution is calculated (press the calculate button) the calculator displays the bearing for the gun, and the elevation for both high and low angle solutions. The colour coding is to help select the correct charge Green good red bad.

Choose a solution, say high angle charge 3.
Send the battery the elevation bearing and charge type. Select one gun to fire.

Gunpowder Shot Over (when Fired)
Birdnest Shot out

No time of flight is included in this version to alert the FO to when the round will impact or "splash"

Once the observer has seen where the round has landed, he can correct it to get it on target. say the round landed from the FO's pos short 100m and to the left of the target 50m

Depending on how confident the FO is he could call for another adjusting round or say for Three rounds fire for Effect, where each gun of the battery would then fire three rounds each.

In the calculator place these values into Add and Right, in the bottom section it will display the adjust elevation and bearing.

www.dslyecxi.com has some great extra reading on arty stuff.

I hope you find this helpful.

Blake.

Change log:
v1.3a
- Changed the version number on the spreadsheet

v1.3
- Changed the initial values to match Jone's new Mortar addon for Arma2
- Added support for Mils as well as degrees, so that it can be used for the maximum number of addons.
- Added Sample Chart for creating quick reference charts, or for designers playing with values to get the desired ranges.
- Tweaked the max elevation settings in the custom function.
- Adjusted the colour coded elevation background threshold values.

v1.2:
- Created Fields to set velocities and air friction for other addons. Unprotect the spreadsheet first.
- Created Ace map version
- Added second bearing angle, One shows 0 <-> 360, other shows -180 <-> 180
- Finally fixed time of flight bug.

v1.1:
- Fixed an error in the adjustments calculations.
- Added time of flight to high angle solutions.
- Changed Dir label to Dir to Tgt.
- Changed design of how solutions are calculated to only calculate either initial or adjusted solutions to improve turnaround time.
- Added an indicator to show when the solution calculations have been completed.
- Increased the maximum angle calculated from 70 to 80 degrees, so if the guns are on an incline (allowing a higher angle of elevation in the dir of incline), this situation can be exploited.

Credits & Thanks:

Forum topic:
- Armaholic forums

- Real Mortars mod

Tags: No tags