Spectra Precision Survey Pro v3.80 Recon iPAQ Reference Manual - Manual (Page 63)

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R-57
Edit Segment – Spiral Card
The Spiral card is used to add a spiral curve to the alignment.
Radius : is the radius of the spiral. (This equals the
radius of the horizontal curve tangent to the spiral.)
Length : is the length of the spiral.
Turn : specifies if the curve turns to the Left or Right
as you face the curve from the beginning.
Dir : specifies if the curve runs from TS to SC (Tangent
to Spiral, to Spiral to Curve) or CS to ST (Curve to
Spiral, to Spiral to Tangent).
; Make this segment tangent to previous : When
checked, will automatically turn the spiral so the
beginning is tangent to the end of the previous segment.
$]LPXWK / %HDULQJ : is used to specify a known
azimuth or bearing of the start of the spiral.