tsc_DistanceOffsetObservation

This is a subclass of tsc_PointObservation, and it's a special circle observation that contains a tsc_RawCircle coordinate and the related disance offset. This type of observation is used to store measurements taken by a total station.

The offsets will apply left and right of the observed horizontal angle, up and down vertically at the observed point and in and out horizontally along the observed line.  Note that apart from locating the original observation the vertical angle and slope distance do not affect the sense of the offsets.

The tsc_OffsetPerspectiveMode will affect the sense of left and right and in and out:

enum tsc_OffsetPerspectiveMode

{

    tsof_OffsetFromInstrument,    Operator looking through the total station reticule at the target.

    tsof_OffsetFromTarget         Operator holding the target looking backs towards the total station.

};

Such an observation can only be appended to the database while a current station setup exists.

Each distance offset observation requires environment information - the station and the target - which are supplied by the tsc_TsEnvironment class and can be sourced from the database or the tsc_TsModes object. An instance of tsc_TsEnvironment should be passed in when setting the tsc_RawCircle and distance offset on the tsc_DistanceOffsetObservation to ensure the correct environment information is stored with the point.