The paper by McGee and Schmidt (1985): https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19860003843.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.

The paper by McGee and Schmidt (1985): https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19860003843.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/198600... "Discovery of the Kalman Filter as a Practical Tool for Aerospace and Industry -- Leonard A. McGee and Stanley F. Schmidt"