28Horizontal datum line and orientation

28 Horizontal datum line and orientation

28 Horizontal datum line and orientation

(1) A surveyor must, for each survey, determine the position of survey marks that define the horizontal datum line.

(2) A surveyor must obtain accurate MGA coordinates for datum connection, accurate MGA orientation and confirmation of the survey.

(3) The survey marks adopted for an accurate MGA orientation must be—

(a) permanent survey marks or reference marks, and

(b) within 1,500m of the land surveyed, and

(c) directly connected, by closed loop—

(i) to each of the other survey marks adopted for accurate MGA orientation and confirmation of the survey, and

(ii) to different corners of the land surveyed.

(4) The grid bearing adopted for accurate MGA orientation must be confirmed by angular and distance connection to a third survey mark that has accurate MGA coordinates.

(5) If confirmation of the measured datum lines reveals differences that are more than the tolerance specified in section 22, the surveyor must survey an additional connection to at least 1 other permanent survey mark or reference mark that has accurate MGA coordinates.