Polynomial filtering up to 5th degree with variable time steps
[Morrison1969] Morrison, Norman, "Introduction to Sequential Smoothing and Prediction", McGraw-Hill, NY, 1969
[Morrison2013] Morrison, Norman, "Tracking Filter Engineering: The Gauss-Newton and Polynomial Filters", IET Radar, Sonar and Navigation Series 23, The Institution of Engineering and Technology, 2013
[RMKdR2012] Reyneke, Pieter, V., Morrison, Norman, Kourie, Derrick G., de Ridder, Corne', "Polynomial Filtering: To any degree on irregularly sampled data", Automatika, Vol. 52, 4, 2012, DOI 10.7305/automatika.53-4.248, https://pdfs.semanticscholar.org/f357/a8d3861d74034138699810944e06e8c9cd5a.pdf