residual: average residual across a measurement type
hs: Multiplier for inclination claculations. +1 if measurment was taken in northern hemisphere, -1 if measurement was taken in the southern hemishpere.
ordinate: Variometer data. Ordinate object(contains a datapoint for H, E, Z, and F)
ud: Multiplier for inclination calculations. +1 if instrument is oriented upward, -1 if instrument if oriented downward.