(SOLVED!) What Is Wgs84 Map Datum?

Prior to advent of satellites, most surveying was done on the ground or by using photos taken from an airplane 🔥 Early maps and surveys were carried out by teams of surveyors on the ground using transits and distance measuring “chains” 🔥 Surveyors start with a handful of locations in “known” positions and use them to locate other features. These methods did not span continents well. Frequently they have also done not cross political borders. The “known points”, their positions and the ellipsoid used are the information that the map datum is based. NAD 23 CONUS datum is one of these terrestrial based datums established from a triangulation station in Meades Ranch, Kansas. [1]
WGS84 is defined and maintained by the United States National Geospatial-Intelligence Agency (NGA). It is consistent, to about 1cm, with the International Terrestrial Reference Frame (ITRF). It is a global datum, which means that coordinates change over time for objects which are fixed in the ground. This is because the tectonic plates on which New Zealand sits are constantly moving, albeit reasonably slowly. In New Zealand this movement is about 5cm per year. This continuous ground movement means that even in the absence of earthquakes and other localised land movements, WGS84 coordinates are constantly changing. These are often referred to as dynamic or kinematic coordinates. Therefore it is important that coordinates in terms of WGS84 have a time associated with them, especially where the best levels of accuracy are required. [2]
Image #2
The researchers from confluence.qps.nl offer us with additional insight. WGS84 is an Earth-centered, Earth-fixed terrestrial reference system and geodetic datum. WGS84 is based on a consistent set of constants and model parameters that describe the Earth’s size, shape, and gravity and geomagnetic fields. WGS84 is the standard U.S. Department of Defense definition of a global reference system for geospatial information and is the reference system for the Global Positioning System (GPS). It is compatible with the International Terrestrial Reference System (ITRS). The current realization WGS84 (G1762) follows the criteria outlined in the International Earth Rotation Service (IERS) Technical Note 21 (TN 21). The responsible organization is the National Geospatial-Intelligence Agency (NGA). NGA plans to conduct a WGS84 reference frame network adjustment in 2013 to incorporate IERS Conventions 2010 Technical Note 36 (TN 36). (last emended 65 days ago by Lary Schrader from Nellore, India) [3]
Image #3
Skybrary.aero also mentions that iCAO specifies the World Geodetic System 1984 (WGS-84) as the geodetic reference datum Standard for air navigation latitude/longitude coordinates. Although most countries meet the requirement, not all locations have adopted, or have completely converted to, the ICAO standard. Jeppesen has compiled and maintains a WGS84 Status Report based on information found in the Aeronautical Information Publication (AIP) (or equivalent publication) of each country. Note that many countries include only international airport and airspace information in their AIP. Therefore, coordinates associated with domestic and military airports and airspace may not be WGS-84 compliant, even if the status report indicates that the country is “compliant”. The Jeppesen Status Report categorises countries as follows: (last modified 80 days ago by Basel Lemus from Basra, Iraq) [4]
Image #4

Article References

  1. https://www.maptools.com/tutorials/map_datum
  2. https://www.linz.govt.nz/data/geodetic-system/datums-projections-and-heights/geodetic-datums/world-geodetic-system-1984-wgs84
  3. https://confluence.qps.nl/qinsy/en/world-geodetic-system-1984-wgs84-29855173.html
  4. https://www.skybrary.aero/index.php/World_Geodetic_System_1984_(WGS84)
Kelly-Anne Kidston

Written by Kelly-Anne Kidston

I am a writer of many words, from fiction to poetry to reviews. I am an avid reader and a lover of good books. I am currently writing my first novel and would love to find some beta readers who are interested in getting an early look.

What Happened To Quinn In Season 6 Of Homeland? [RESOLVED]

(SOLVED!) What Did The Temple Of Athena Look Like?