Spectra Precision Survey Pro v4.6 Recon-Nomad Reference Manual - Manual (Page 409)

Curve Menu
R-401
Spiral
Curve Spiral .
The Spiral screen will compute the details of a spiral curve, given the
spiral length and radius.
Spiral length: is the length of the spiral curve.
Radius: is the circular curve radius.
Solve : computes the details of the spiral curve.
Layout… : accesses the Spiral Layout screen (Page R-
402) where the location of stations on the spiral curve
can be computed.
Traverse… : accesses the Traverse on Spiral screen
(Page R-403).
Results
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.