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| docs:autocad:land_desktop:establishing_a_spatially_accurate_drawing [2007/04/25 15:36] – created billh | docs:autocad:land_desktop:establishing_a_spatially_accurate_drawing [2008/08/03 00:25] (current) – external edit 127.0.0.1 | ||
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| + | ====== Autodesk Land Desktop: Establishing a Spatially Accurate Drawing ====== | ||
| + | This procedure will create a drawing project that will be accurate with planar coordinates as well as spatial coordinates, | ||
| + | ===== Prerequisites ===== | ||
| + | * a known point in the drawing, representing a Latitude/ | ||
| + | * rotation of true North, if not straight up | ||
| + | * a local geodetic coordinate system, using the same units as your drawing | ||
| + | |||
| + | ===== Scope ===== | ||
| + | * define a spatial coordinate system for the drawing coordinate system | ||
| + | * allow a local coordinate system to be used, such as for surveying purposes | ||
| + | * allow .shp files to be imported accurately | ||
| + | |||
| + | ===== Procedure ===== | ||
| + | (this will be shown after the project has been created, so that older files may be updated as well) | ||
| + | - open an existing project | ||
| + | - go to Map -> Tools -> Assign Global Coordinate System | ||
| + | - select the appropriate coordinate system for the file, using the same units (Example: Category=USA, | ||
| + | - if you have objects in the drawing, you may need to move them now to match up with the coordinate system you just selected | ||
| + | * tip: if you don't know the coordinates of the local system, but you do know the WGS84 Lat/Long, simply use the Map -> Tools -> Track Coordinates tool to digitize a point using WGS84 Lat/Long (or any other system); then move your objects to the new point | ||
| + | - once your objects are positioned properly in the drawing, you may want to set up a custom Northing/ | ||
| + | - Projects -> Drawing Setup -> Orientation tab | ||
| + | - use the Base Point dialog to select a point on your drawing that will correspond to a Northing/ | ||
| + | - you may also use the North Rotation to define another direction for North, rather than straight up | ||
| + | - you should now be able to: | ||
| + | * import/ | ||
| + | * import/ | ||
| + | * digitize, locate, inquiry etc... any point on your drawing, with geodetic accuracy | ||
| + | |||
| + | ===== Points of Confusion ===== | ||
| + | * the Autocad coordinate system (X,Y) will have to match up with the local coordinate system of the earth, such as | ||
| + | HARN(HPGN)Arizona State Planes, Central Zone, US Foot | ||
| + | * your points will NOT use the Autocad coordinate system (X,Y), but instead use a Northing/ | ||