Kalman filters (htmlpreview.github.io)
This is a great explanation on how to use a kalman filter to use data from two sensors to make measurements that are more precise than the individual inputs.
These are all articles and videos I have completely read or watched. I have listed them because I have gotten value out of them and believe they offer value to others. The references are things that I have not read in completion, but use to look up useful tidbits of information.