World Geodetic System 1984

Using the protractor, measure the smaller angle between the beam and the plumb line. If the sun is directly over the Equator, this is your latitude reading. The angle to measure when using the sun or North Star. Note that the horizon is always 90º to the plumb line.

A latitude reading will tell you how far north or south a location is. The North Pole is at 90 degrees latitude (or 90.0° N) and the south poles is at -90 degrees latitude (or 90.0° S).

A grid system or graticule is formed in this manner using a base of two perpendicular circles. Latitude measures the number of degrees north or south of the equator which has a latitude of 0�. Lines of latitude (parallels) run east-west around the globe and are used to measure distances NORTH and SOUTH of the equator.

Tell students that the lines running across the page are lines of latitude, and the lines running up and down the page are lines of longitude. Latitude runs 0–90° north and south. Longitude runs 0–180° east and west.

The difference is that WGS 84 is a geographic coordinate system, and UTM is a projected coordinate system. Geographic coordinate systems are based on a spheroid and utilize angular units (degrees).

2-5 metres

Datums are used in geodesy (the branch of mathematics dealing with the shape and area of the earth), navigation, cartography and by Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS) and the Global Orbiting Navigation System (GLONASS).

On a construction project, a datum level is an arbitrary horizontal plane of reference from which all vertical dimensions are measured. It can show the vertical height difference between floor levels of a building as well as differences in levels between one part of the site and another.

In the Continental United States use NAD27 CONUS.) The Global Positioning System uses an earth centered datum called the World Geodetic System 1984 or WGS 84. WGS 84 was adopted as a world standard from a datum called the North American Datum of 1983 or NAD 83.

A datum reference or just datum (plural: datums) is some important part of an object—such as a point, line, plane, hole, set of holes, or pair of surfaces—that serves as a reference in defining the geometry of the object and (often) in measuring aspects of the actual geometry to assess how closely they match with the …

WGS84 datum

There are two main datums in the United States. 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.

A datum feature is a part feature (or FOS), that contacts a datum during measurement. A datum is a theoretically exact plane (or axis or center-plane), from which dimensional measurement should be made. During measurement, the datum feature will contact the simulated datum which in this case is a surface plate.

The datum features on a drawing are denoted with a series of capital letters. These letters are in boxes and tied to the datum feature with a black triangle. This letter will also show up in any feature control frame that uses this datum feature as a reference.

A tolerance is an acceptable amount of dimensional variation that will still allow an object to function correctly. Three basic tolerances that occur most often on working drawings are: limit dimensions, unilateral, and bilateral tolerances.

something known or assumed; information from which conclusions can be inferred. see also data. a real or assumed thing, used as a basis for calculations or measurements, as a level (also datum plane) from which elevations and depths are measured in surveying.

An example of a datum is a new scientific discovery used to reach a conclusion about the common cold. An example of a datum is the assumed altitude of a specific piece of land used as the basis in calculating the altitude of the top of a mountain on the land. noun.

Adindan is a geodetic datum determined in 1958 and suitable for the use in Sudan, South Sudan, Ethiopia and Eritrea. The reference ellipsoid of Adindan is Clark 1880, and its origin is 22° 10′ 7.1098″ latitude, 31° 29′ 21.6079″ longitude. Specific Area or country should only use its associated datum.

In English, the word datum is still used in the general sense of “an item given”. Any measurement or result is a datum, though data point is now far more common. Data is most often used as a singular mass noun in everyday usage. Some major newspapers, such as The New York Times, use it either in the singular or plural.

What is another word for datum?

North American Datum of 1983

Charted depths and drying heights on nautical charts are given relative to chart datum. One may calculate whether an area that dries is under water by subtracting the drying height from the [given] height calculated from the tide table.

Mean Sea Level (MSL) is a tidal datum which is computed by the National Ocean Service (NOS), Center for Operational Oceanographic Products and Services (CO-OPS) as part of the National Tidal Datum Epoch (NTDE) based on data collected over a 19-year tide cycle.

[′char·təd ′depth] (oceanography) The vertical distance from the tidal datum to the bottom.

The soundings printed on the chart normally represent the depth at mean lower low water (MLLW), so the actual depth is usually more than the charted depth. However, when the tide table shows a negative low-tide entry, actual depths will be less than the chart indicates.

G Topographic Terms. HYDROGRAPHY. H Tides, Currents. I Depths. J Nature of the Seabed.

6 feet

Numbers on a nautical chart are depth measurements. The depths may be in either feet or fathoms (the chart will indicate which). A fathom is a nautical unit of measurement and is equal to six feet .