| (1) | A land surveyor shall determine the positions of all stations and beacons within the limits of accuracy prescribed in regulation 5 and shall check every part of his or her survey. |
| (2) | Unless otherwise adequately checked, the minimum requirements for the determination of the position of a point are: |
| (a) | when its position is determined by intersection or trilateration, the angle at the vertex of any triangle used in such determination shall not be less than 30 degrees nor greater than 150 degrees; |
| (b) | when its position is determined by resection, at least four favourably situated known points shall be used, and sufficient observations shall be made to ensure the required accuracy of determination of its position: Provided that at least one arc shall be observed; |
| (c) | when its position is determined by a single triangle only, observations shall be made at all three points and on at least two different parts of the circle; |
| (d) | when its position is determined by GNSS, at least two known points or two independent vectors shall be used; |
[Regulation 3(2)(d) substituted by section 2 of Notice No. 645 of 2013]
| (e) | when its position is determined by photogrammetric methods, it shall: |
| (i) | fall wholly within the perimeter of the ground control points; |
| (ii) | be measured in at least two stereoscopic models where the base/height ratio shall not be greater than 0,80, or be measured in at least four photographs for bundle intersections, where the intersection for any pair of rays shall not be less than 30 degrees and not greater than 150 degrees; |
| (iii) | be positively identified on the photographs by the land surveyor. |
| (3) | When traversing between two known points, observations shall be taken at both known points, unless the orientation is otherwise adequately checked. |
