AS 3962:2020 pdf free download.Marina design. A uniform survey grid should be adopted for the total project area. All terrestrial and hydrographic surveys should use this survey grid. Consideration should be given to incorporating the survey grid for the project area into the regional coordinated survey grid, e.g. Mapping Grid Australia (MGA). Where a local survey grid is adopted, this should be clearly noted on the drawings. The correlation to an established regional coordinated grid should be nominated on the drawings. 2.1.1.2 Survey datum All survey data shall be reduced to one of the following recognized datum: (a) Chart datum (CD) — the preferred datum for surveys and mapping of marine works and offshore topography, as it provides direct correlation to navigable water depths. (b) Australian Height datum (AHD) — the preferred datum for terrestrial surveys, but this often does not have a definitive correlation to CD at specific locations. All survey and design levels within any project shall be reduced to the same datum. A diagram showing the correlation between survey marks, AHD and CD for the specific location shall be provided on the drawings. 2.1.2 Hydrographic survey Where there is insufficient survey data to make an assessment of…