Download projection file utm zone 12, datum nad83.

Actually, because of these changes, there is more than one version of NAD For example, the National Geodetic Survey has adjusted the NAD83 datum four times since the original geodetic datum estimation in The coordinates for benchmark datum points are typically different between geodetic datums. This difference is known as a datum shift. To be clear, most monuments have not moved. Datum shifts happen because survey measurements improve. Also, it happens when there are more of them and methods of geodesy change.

This results in more accurate geodetic datums over time. The horizontal datums that form the basis of coordinates of all horizontal positions in North America improve. Because maps were created in different geodetic datums throughout history, datum transformations are often necessary. Especially, this is true when using historical data. You would need to apply a datum transformation when working with NAD83 data. A coordinate transformation is a conversion from a non-projected coordinate system to a coordinate system.

A coordinate transformation is done through a series of mathematical equations. The geodetic datum is an integral part of projections. All coordinates are referenced to a datum. A datum describes the shape of the Earth in mathematical terms. A datum defines the radius, inverse flattening, semi-major axis, and semi-minor axis for an ellipsoid.

It provides latitude and longitude and some height information. Before the current datum was defined, many maps were created using different starting points. Autodesk does not warrant, either expressly or implied, the accuracy, reliability or completeness of the information translated by the machine translation service and will not be liable for damages or losses caused by the trust placed in the translation service.

Back to Civil 3D Category. Back to Topic Listing Previous Next. Filter by Lables. Message 1 of Many thanks. Message 2 of Rick Jackson Survey Technician. Message 3 of Message 4 of Thanks for taking a look at this Dave. Which version of C3D are you using? I'm not sure what is going on. Message 5 of Set your shortcut for C3D to "run as admin" that reduces map etc issue It is also nice because it does a great job of preserving the shape of real world objects modeled in your GIS.

NAD83 became the statewide datum standard beginning in Web Mercator is relevant for 2 reasons and both reasons are related to basic, map display functions. First, it is great for maps of large areas, where more than the state of Utah may be needed. Second, it has become, and will likely remain for some time, the de facto coordinate system standard for web mapping applications, because, as mentioned above, it works well for maps depicting the portions of the globe we care about most, and because it performs coordinate conversion faster.

The gnomonic projection is not equal area or equidistant. These two properties increase as you move away from the center point. Stereographic This projection maintains direction from the center point. Each line represents a great circle. The stereographic projection is not equal area or equidistant.

Orthographic The orthographic projection involves projecting the globe onto a plane with the point of projection as infinity. As indicated in the name, all projection lines are orthogonal to the projection plane. This is a map projection commonly used for inset maps. Continue Reading. This projection maintains direction from the center point. The orthographic projection involves projecting the globe onto a plane with the point of projection as infinity. This sub-clause defines the geographic coordinate system.

This sub-clause defines the horizontal reference datum. This sub-clause defines the reference meridian used for longitude measurements. This sub-clause defines the projected coordinate system used to convert geographic coordinates to projected coordinates. This sub-clause defines the units used to measure distance.