Sounding Datum and Chart Datum: Definitions  Sounding Datum is the plane to which soundings are reduced during a hydrographic survey. It is the datum
{"Image DocumentName": "Sounding Datum and Chart Datum: Definitions", "Image ImageDescription": "Sounding Datum is the plane to which soundings are reduced during a hydrographic survey. It is the datum used when compiling a survey fairsheet and should be connected to chart datum via a landborne benchmark (BM). Chart Datum is the datum plane adopted for the published chart and is the level above which charted depths, tidal predictions and tidal levels are given in the Australian National Tide Tables (ANTT), AusTides and on the published chart. Ideally, sounding datum for a survey should be the same as the chart datum.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}