Reddit reviews Strapdown Inertial Navigation Technology (Radar, Sonar and Navigation)

Please don't delude yourself that knowing which buttons to press in Matlab is a substitute for actually knowing the material.

I suggest you buy this book. Then you'll have a chance of understanding what Matlab is doing under the hood, and you can just do what needs to be done. And no, the book doesn't mention Matlab, to my knowledge -- it just explains how the math actually works.