Uses as many measured angle values as are available (a minimum of three sets) to recreate the wellbore path through Simpson's rule for numeric integration, which approximates by passing a parabola through three points. (Bul D20)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}