The direction of a survey leg with respect to the preceeding leg of the survey traverse. Several measuring conventions are used (Figure A-13). The first leg of the traverse is usually specified by azimuth or compass direction. Azimuth angles are measured clockwise with respect to north (either true north or magnetic north), occasionally with respect to south. Interior angles are the angles lying inside a closed traverse. Angles right are measured clockwise after backsighting on the previous station. A deflection angle is the angle between the onward extension of the previous leg and the line ahead.
FIG. A-13. Angle measuring conventions. Specifying by (a) interior angles, (b) angles right, (c) deflection angles, (d) azimuth angles. The first leg of a loop is specified by azimuth.