OBSERVATIONS BASED COORDINATES

Although coordinates have an important role in Landonline, the most important information for survey definition is observations - traverse observations, boundary ties and boundary dimensions.

Prior to Landonline, surveyors were required to supply adjusted coordinates on traverse sheets and ensure these were based on the most appropriate and up-to-date origin coordinates. In Landonline, and particularly for e-surveys, the role of coordinates supplied by the surveyor is greatly diminished. What is still important is connections to well defined origin points which, where practicable, should be geodetic marks or traverse marks connected to geodetic marks.

For all marks new to Landonline (which includes new survey marks as well as old or adopted traverse marks that have not yet been captured) an approximate coordinate is required. This allows Landonline to display the layout of the survey correctly. The coordinates provided by the surveyor are subsequently changed in Landonline. After approval of the survey, a cadastral network adjustment is carried out using least squares. This generates authoritative coordinates that may play a role in future survey work. The approximate coordinates supplied by the surveyor play no future role.

This also means you need not be concerned if you extract coordinates from Landonline and the coordinates for these points are subsequently updated in Landonline. Even in this case, though the coordinates submitted with the survey would differ from the new official coordinates in Landonline, this would not affect validation and approval of the survey because validation makes no use of the surveyor-supplied coordinates. Validation only relies on the survey accurate coordinates in Landonline and the surveyor's observations.

In the past LINZ placed considerable reliance on the coordinates supplied by surveyors. Often surveyors were requisitioned for issues concerning the source of their coordinate origins. The removal of these requirements for e-surveys represents a significant change.

This will reduce the effort currently spent by surveyors to search for the latest coordinates and will reduce the risk of requisition. The need to access historical traverse sheets will be limited to cases where clarification is required of hard-to-read observations on the paper plan or to check the misclose in underlying work.