Please see the UserManual
Kyle Wolma retooled and improved my original code.
This code was used for the work described in this paper:
Larson, K.M., A Methodology to Eliminate Snow and Ice-Contaminated Solutions from GPS Coordinate Time Series, J. Geophys. Res, Vol. 118(8), 4503-4510,doi:10.1002/jgrb.50307, 2013 (pdf)
Kristine M. Larson May 2, 2020