Yes. I was director of Research and Innovation in a company that produces equipment for people to do VTS and VTMIS, which is the maritime equivalent of Air Tra

Yes. I was director of Research and Innovation in a company that produces equipment for people to do VTS and VTMIS, which is the maritime equivalent of Air Traffic Control. We track targets (mostly ships, mostly maritime, but not always) and we use Kalman Filters (and variants) extensively. https://en.wikipedia.org/wiki/Kalman_filter#Nonlinear_filters https://en.wikipedia.org/wiki/Kalman_filter#Nonlinear_filter... Contrary to your experience, there was a time when we were ridiculed for not using Kalman Filters, but in the limited niche we inhabited then, our internally developed algorithms out-performed Kalman. But mostly, these days, yes, we use Kalman Filters of various types.