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How To: Use tangent bearings in COGO

Summary

Instructions provided describe how to use tangent bearings in COGO. The tangent bearing can be used by finding the radial bearing, the bearing pointing to the curve's center, if the tangent bearing is going into the beginning point. Once the radial bearing is known, the TRAVERSE command can be used.

Procedure

Users need to enter a curve with the following data:

  radius
tangent bearing
arclength

The TRAVERSE command only accepts the following curve parameters:

arclength
chord
delta
radius
radial direction (non-tangent curve)
tangent

  1. Find the radial bearing, the bearing pointing to the curve's
    center, by adding 90 degrees to the tangent bearing.

    Code:
    Arcedit: &ty [calc [angrad s63-27-56e] + [angrad 90]]
    7.390868213232
    Arcedit: &ty [radang 7.390868213232 -dms -bearing]
    N26-32-04E

  2. Use the radial bearing in TRAVERSE as RDDRN

    Code:
    Arcedit: TRAVERSE OPEN 0,0
    course (1): N79-03-04W 10.83
    course (2): N11-20-30E 161.46
    course (3): NTCLEFT RDDRN N26-32-04E