=This is the datum plane adopted by the national authority for its published chart and tidal predictions.
= The datum only is used around of tidal observation.
= It is different at different locations.
= Depends on the range of tidal or water level.
= It will only be the same as the SD when the Hydrographic Office has analyzed the survey data and confirmed the suitability of field surveyor’s choice. The surveyor cannot establish CD in field.
= CD is defined by the International Hydrographic Bureau (IHB) as a level below which the tide will but seldom fall.
= In none-tidal waters, CD is normally established at MSL.
= Because LAT is so difficult to define precisely, CD for Admiralty and Australian charts has been more broadly defined as the level below which no predicted tide shall fall more than 0.1m.
Tiada ulasan:
Catat Ulasan