gama-local SQLite database, distances are given in meters
and their standard deviations (rms errors) in millimeters.
Angular values are given in radians as well as their standard deviations.
Conversions between radians, gons and degrees:
rad = gon * pi / 200 rad = deg * pi / 180 gon = rad * 200 / pi deg = rad * 180 / pi