Traditional flat map making methods are making it possible. See the following article:
The Earth is Not Round! Utah, NAD83 and WebMercator Projections
The above article explains that on the inside of the spherical models such as WebMercator (the web based version of WSG 84), it takes data from a mess of smaller flat maps to present more accurate data. The flat maps are more accurate, as the author describes.
Fact Check:
False No where in the article does it state: "it takes data from a mess of smaller flat maps to present more accurate data."
The article states this about WebMercator (the web based version of WSG 84): "In short, it uses the same WGS84 datum as the GPS system.”
World Geodetic System (WGS84)
"The Global Positioning System uses the World Geodetic System (WGS84) as its reference coordinate system. It comprises of a reference ellipsoid, a standard coordinate system, altitude data and a geoid.
Because the Earth is curved – and in GIS we deal with flat map projections – we need to accommodate both the curved and flat views of the world. Surveyors and geodesists have accurately defined locations on Earth.”
https://gisgeography.com/wgs84-world-geodetic-system/NAD83 = Flat Map Coordinate System
Fact Check:
Misleading"The North American Datum of 1983 (NAD 83) is the most current datum being used in North America. It provides latitude and longitude and some height information using the reference ellipsoid GRS80.”
NAD83 is derived from an ellipsoid earth model, not a flat earth model.
https://en.wikipedia.org/wiki/State_Plane_Coordinate_System
The State Plane Coordinate System (SPS or SPCS) is a set of 124 geographic zones or coordinate systems designed for specific regions of the United States. Each state contains one or more state plane zones, the boundaries of which usually follow county lines. There are 110 zones in the contiguous US, with 10 more in Alaska, 5 in Hawaii, and one for Puerto Rico and US Virgin Islands. The system is widely used for geographic data by state and local governments. Its popularity is due to at least two factors. First, it uses a simple Cartesian coordinate system to specify locations rather than a more complex spherical coordinate system (the geographic coordinate system of latitude and longitude). By using the Cartesian coordinate system's simple XY coordinates, "plane surveying" methods can be used, speeding up and simplifying calculations.
Fact Check:
MisleadingYou left off the last two sentences from the paragraph:
"Second, the system is highly accurate within each zone (error less than 1:10,000).
Outside a specific state plane zone accuracy rapidly declines, thus the system is not useful for regional or national mapping."
NAD83 is a flat coordinate system.
Fact Check:
MisleadingIt is a datum based upon an ellipsoid earth model, not a flat earth model.
Web Mercator = WSG 84
The full name of Web Mercator is WGS 84 Web Mercator
https://en.m.wikipedia.org/wiki/Web_Mercator_projection
While the Web Mercator's formulas are for the spherical form of the Mercator, geographical coordinates are required to be in the WGS 84 ellipsoidal datum.
It's a web-based version of WGS 84. The WGS part is also mentioned in the Earth Not Round! article.
Fact Check:
TrueWeb Mercator & WGS 84 are based on a spherical earth.
NAD83 is one of them. These are all flat coordinate systems for different locations around the earth. It's taking data from flat systems, because as the "Earth Not Round!" article said, it is these flat systems that are more accurate and give out more accurate figures.
Fact Check:
FalseAs shown above, it is not taking data “from flat systems”, it is taking data from, among other things, a spherical (ellipsoid) earth model, not from a flat earth model.
Show Posts
