When you are designing a collection strategy for your airborne sensor (which is moving), how do you define the azimuth and elevation angles for your sensor pointing? You have a pointing vector from a known fixed source in the body of that fixed source, but what you need are pointing vectors from a moving source. You could do the following:
- Convert the static pointing vectors you have from the body frame of the source to an inertial frame.
- Find position vectors to your moving platform in the inertial frame.
- Calculate difference vectors between the vectors from step 1 and vectors from step 2.
- Convert these vectors to the body of your moving platform
You could do all this, but there is a trick in STK that will have STK do all that math for you.
First, you need to have a known mapping pattern. You can create this via any number of methods. I created this one as a step/stare pattern using a stationary sensor with a specified sensor slew rate, settle time, and dwell time.
Secondly, set up a ground vehicle with an ephemeris using the timing and locations of your mapping pattern. I used a script that aligns a ground vehicle with a sensor boresight. Turn off the graphics of this vehicle so that it’s not visible in the 2D or 3D window.
Finally, set the sensor on your moving platform to target this ground vehicle.
You can then report out the pointing information of the sensor and use that to drive your physical sensor pointing.