What is the meaning of vertical datum?

The vertical datum is a collection of specific points on the Earth with known heights either above or below mean sea level. Near coastal areas, mean sea level is determined with a tide gauge. In areas far away from the shore, mean sea level is determined by the shape of the geoid.

What is the difference between CGVD2013 and CGVD28?

CGVD28 is a tidal datum defined by mean sea level whereas CGVD2013 is a gravimetric datum defined by an equipotential surface known as a geoid. CGVD28 was realized using levelling observations whereas CGVD2013 was realized using satellite measurements of gravity and Global Navigation Satellite Systems.

What is the current vertical national datum?

1. National Geodetic Vertical Datum of 1929 (NGVD29) Commonly used vertical datums in North America are the National Geodetic Vertical Datum of 1929 (NGVD29) and the North American Vertical Datum of 1988 (NAVD88).

What are the different vertical datums?

Vertical datums come in three categories: those based on a form of Mean Sea Level (MSL), called orthometric datums, those based on tidally-derived surfaces of high or low water, called tidal datums, and three-dimensional (3-D) datums realized through space-based systems such as Global Positioning System (GPS) which are …

How is a vertical datum set?

You can set the Vertical Datum using the Search button to launch the Search Dialog which will search on vertical coordinate systems only. Note that this is typically set via your choice of the Geoid Height Model and/or Height Correction Model.

What is CGVD2013?

The Canadian Geodetic Vertical Datum of 2013 (CGVD2013) is the first major update to the vertical datum in Canada in almost 100 years. Canada is not only moving to a new vertical datum, but it is also using a modernized approach to realize it.

What does NAVD stand for?

North American Vertical Datum
The vertical control datum established for vertical control surveying in the Unites States of America based upon the General Adjustment of the North American Datum of 1988. It replaces the National Geodetic Vertical Datum (NGVD) of 1929.

What vertical datum does WGS84 use?

In this case WGS84 refers to a vertical datum or a vertical reference level. Important to know here is that the elevation that comes with the pictures acquired by your drone uses WGS84 as the vertical datum. Often the end user will require the elevation model with respect to a different vertical datum.

What are horizontal datums?

Horizontal datums measure positions (latitude and longitude) on the surface of the Earth, while vertical datums are used to measure land elevations and water depths.

What is the vertical datum for nad83?

The North American Datum of 1983 (NAD 83) and the North American Vertical Datum of 1988 (NAVD 88) provide a more accurate representation of the Earth’s shape and a more accurate depiction of the location of objects in North America than previous datums.