There are plenty of control theory ebooks in the ebooks upload/download section of this forum that can help you in your aim.
I recommend the ff:
Advanced Control Engineering*
Modern Control Engineering*
Stochastic Models, Estimation and Control by Peter Maybeck, (excellent) and
Kalman Filter books, since this is about optimal estimation --
Kalman Filtering: Theory and Practice*
Tracking and Kalman Filtering made easy*
*available in ebooks section
All of these books are heavy in mathematical foundations and theory, and I think they are just what you need. Hope this helps.