Spectra Precision Survey Pro v4.5 Recon and Nomad Reference Manual - Manual (Page 400)

Survey Pro Reference Manual
R-392
Results
Tangent In: the tangent direction entering the spiral at the TS or
CS.
Tangent Out: the tangent direction exiting the spiral at the SC or
ST.
X of Throw: is the distance along the tangent where a perpendicular
line intersects with the radius point.
Y of Throw: is the minimum distance between the tangent and the
extended circular curve.
X: is the distance from the TS to the SC along the tangent.
Y: is distance from the SC to the tangent.
Delta: is the angle between the tangent, and the line between the PI
and SC.