Air Strikes and STK

By: Rich DeYoung

The super intelligent folks at AGI put together great presentations depicting battlefield simulations with all the bells and whistles (the BIG picture). They’re impressive and informative. This blog is directed to those of you who actually perform combat or combat support roles. This is geared towards you Captains, Lieutenants, and enlisted folks who grind their teeth in their sleep owing to a day’s work.

A while back, I was part of a 25-member team performing combat and combat support missions. Supporting as part of a big picture, we mission planned for our small part and worked as a team when the crap hit the fan. Today, the Global Positioning System (GPS) is essential to just about everyone performing their combat role. There are many tools used by our small units that are “approved” by the Department of Defense and for the most part work. I would counter with a question. Why do you find the folks getting shot at continuously jerry rigging approved gear? I can’t fully answer my own question, but one reason is it’s usually due to the approved equipment lacking in one way or another and people simply want to stay alive. STK can help. 

GPS works great when the terrain is flat. Without mentioning any particular country, many of our service men and women are operating is areas of high mountains and low valleys. GPS can struggle in these areas. So, you are in one of these areas and need to call in a precision strike. Let’s say the bad guys are close and precision is the difference between having a non-approved cold one later in the day or, at best, an IV in a hospital. The bomb of the day is a 500 pound all-weather "smart" munition. It’s going to be a ground burst. You would like it to hit at least 250 meters away from your position, but in a pinch you’ll accept 150 meters.

Prior to deploying, you can set up a small scenario in STK of the mission area and preload the day’s GPS Constellation that inserts GPS Satellites using the GPS Almanac and GPS Propagator. Use the GPS Satellite Outage Tool to determine any GPS outages. To further enhance the analysis, use a 30 meter resolution NIMA/NGA DTED terrain file. On top of the analysis, you will use STK’s outstanding 3D graphics as a pre-mission briefing tool for situational awareness. 

Insurgents are moving supplies through an area surrounded by very steep terrain. Using STK’s Coverage module, you will determine when it’s safe to call in an air strike. Narrow down the analysis area by employing an ellipse Area Target object with a radius of one (1) kilometer.

Inserting a Coverage Definition object, make the Grid Area of Interest the Area Target. Set the Grid Definition – Point Granularity to 30.5 meters or less. Ensure the grid is using Altitude above Terrain. By creating a mask file for the Place object that you’re using as a visual representation point for the insurgents, and using the Az-El mask file as an Az-El Mask constraint, the constraint can be applied to your grid. Think of each grid point as a potential insurgent location. Finally, assign the GPS Constellation object as your coverage asset

Due to the size of the analysis area, the grid point resolution, and the number of satellites, computing accesses in parallel is a good idea if you’re employing a computer that contains a multi-core processor. Once the computation is complete, configure a Figure of Merit object to use Navigation Accuracy. In this instance, it seems prudent to use the following settings: 


After configuring the Figure of Merit, use the Navigation Uncertainties tool (GPS Satellite Outage Tool) to apply Asset Range Uncertainties to your analysis. The following shows the difference using constant values and actual values: 

Constant Uncertainties

Actual Uncertainties 

Creating animation color contours, set your values at zero (0) meter for minimum and 90 meters for maximum. In the following example, anything red is 90 meters or worse. If the insurgents were in a red area and you are within 250 meters of that area, you won’t call in a strike at that particular time. 

In the Report & Graph Manager, generate a Grid Stats Over Time report. This report will show you blocks of time when you can call in a strike no matter where you’re located in the mission area. In the following example, you have an eleven minute window to call in a strike no matter the location in the grid if you’re willing to accept an uncertainty of approximately 30 meters. 

If you know the grid point that the insurgents are located at, you can use the 2D Graphics window and the Grid Inspector Tool to generate a report or graph that tells you when that spot falls out of your 90 meter window. In the following example, you see a graph that quickly tells you when you can and cannot call in a strike. 


STK gives you terrific analysis and outstanding visual situational awareness. We have a tutorial called Position Accuracy in Mountainous Terrain that walks you through most of the steps in this blog. Picture your approved software and compare it to STK. Which one would you like to use? 

Posted: 9/25/2017 9:42:30 AM