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Equal-area and equidistant projections appear in the National Atlas. Other projections, such as the Miller Cylindrical and the Van der Grinten, are chosen occasionally for convenience, sometimes making use of existing base maps prepared by others. Some projections treat the Earth only as a sphere, others as either ellipsoid or sphere.
- USGS Publication
Equal-area and equidistant projections appear in the...
- USGS Publication
Equal-area and equidistant projections appear in the National Atlas. Other projections, such as the Miller Cylindrical and the Van der Grinten, are chosen occasionally for convenience, sometimes making use of existing base maps prepared by others. Some projections treat the Earth only as a sphere, others as either ellipsoid or sphere.
A flat map can show one or more--but never all--of the following: True directions. True distances. True areas. True shapes. Different projections have different uses. Some projections are used for navigation, while other projections show better representations of the true relative sizes of continents. For example, the basic Mercator projection ...
- Determine What Projection Your Source Map Is in
- Find The SRID of Your Target Projection
- Convert The Shapefile to The New Projection
- Save Your New Map with A Useful Filename
This will vary with what kind of spatial file you’re using, but we’re assuming shapefile. A shapefile actually is a folder containing several files. There are sometimes more, but shapefiles almost always have a .shp, a .dbf and a .prj file. As you might have guessed, the projection information is in the .prj file. Here’s a .prj file from a Californ...
There are a few ways you might find the SRID of the new projection you want. If you found the projection on a government mapping site, the site might list the EPSG IDof the projection. If you’re not lucky enough to have an SRID in hand, your next best friend is a search engine and spatialreference.org. For example, if you need to look up the Google...
In Quantum GIS, this is as easy as right-clicking the layer you want to project, choose Save As, then choose Browse next to CRS (that stands for coordinate reference system), and search by EPSG.
This seems like a minor point, but I have maybe 10 identical shapefiles of the California state border in different projections. Do yourself a favor and include the SRIDin the filename (e.g. california_border_4326.shp).
Lambert Conformal Conic are used. Equal -area and equidistant projections appear in the National Atlas. Other projections, such as the Mi ller Cylindrical and the Van der Grinten, are chosen occasionally for convenience, sometimes making use of existing base maps prepared by others. Some projections treat the Earth only as a sphere, others as ...
CanVec – The Atlas of Canada's 1:1 000 000 National Scale Framework; CanVec – 1:250 000 scale National Topographic Data Base; CanVec – 1:50 000 scale CanVec; More information on the data used in Toporama - Mapping Tool can be found on our Map Sources page. 4. What projection / coordinate system, datum and ellipsoid are used for Toporama ...
People also ask
Which projections are used in the National Atlas?
Which conformal projections are used in the National Atlas?
What are the different types of Earth projections?
How many map projections does the USGS use?
Why is the National ATLAST equal area projection different?
What is a map projection?
projections such as the Transverse Mercator and the Lambert Conformal Conic are used. Equal-area and equidistant projections appear in the National Atlas. Other projections, such as the Miller Cylindrical and the Vander Grinten, are chosen occasionally for convenience, sometimes making use of existing base maps prepared by others.
