It's all about time
- Jun 1, 2020
- Tech Tip
- Analysis Workbench
Several recent blog posts have highlighted the amazing and useful things you can do with Analysis Workbench (namely, How I solved two customer use cases with Analysis Workbench and Visualizing STK Intervals). I'd like to use these examples as a springboard to talk about an underlying concept - the idea that in STK, it really is All About Time. We don't call STK a 4D analysis tool for nothing - sure, the 3D graphics are beautiful and analytically powerful, but that fourth dimension of Time is perhaps the most powerful of all!
Along with satellites and transmitters and multi-hop chains and all the other objects in STK, Analysis Workbench (AWB) lets you construct building blocks out of Time itself, and use those building blocks to accomplish other tasks in STK. Even better, the AWB lets you tell STK about analytical things that you think are important - and then STK will tell you about the times when those analytical things occur by building those Time blocks for you!
What do I mean by that? Well, by using the Calculation Tool in AWB, you can build Scalars - which are numerical values that may change over time - and then you can set boundaries on those numbers. For example, you may have an angle that must fall inside a certain min/max range of values, or a separation distance whose second derivative must be below some threshold - you can build those concepts up in the Calc Tool. Then, without you having to do any more work, the Time Tool portion of the AWB will kick in and automatically create those building blocks of time - called Intervals (or Interval Lists) - for the times when your condition is true. Then you can get really fancy in the Time Tool itself and combine intervals and do logical math on them...there's really no limit to the things you can accomplish!
Let me give you a more concrete example. Let's say that I have an aircraft with sensors arrayed in quadrants around the body of the vehicle. My aircraft tracks other aircraft, and for my analysis I need to know which quadrant the other aircraft is in, so that I can make use of different Sensor objects. Well, using the AWB, I can first build up the Vector that points from my aircraft to the other aircraft, relative to the nose of my own vehicle. Then using the Calc Tool, I can create a Scalar that grabs the numerical value of the angle. Finally, I can create a Condition Set and assign boundaries at 0, 90, 180, 270, and 360 degrees. Then, the AWB will automagically create Interval Lists that tell me when the angle value is in each one of the resulting quadrants!
"Well, so what?!" - you might say. "Here's where the real power is revealed," would be my answer. Now that you have those Time Intervals, you can apply them to other objects, all throughout STK, to accomplish your analytical goals! Want to turn one Sensor Off and another one On? You can do that with Intervals! Want to tell your Satellite to stop tracking one ground target and start tracking another? You can do that with Intervals! Want to tell your Aviator Aircraft to interrupt its current procedure and start doing something else? You guessed it - Intervals! (Or Instants, which are also automagically created along with Intervals.) The applications are endless - and require no scripting! (And if you really want to do some scripting to create and manipulate Intervals...well, you can do that too!)
Want to get started building up AWB constructs yourself? I thought you might be! Here's the best place to start - a tutorial that walks you through the whole Analysis Workbench and uses all the tools I've described here!