Albers Equal Area Conic
Flat maps will show distortions when portraying the shape of the earth. Maps can show true directions, distances, areas or shapes but never all of these at one time.[1] Map projections are required to account for such distortions. Each projection is suitable to address the distortion issues and to best represent the globe for a particular purpose.
The Albers Equal-Area Conic Projection was developed by German scientist Heinrich Christian Albers in 1805 three months after Mollweide presented his elliptical world map in the same journal. Albers (1773-1833), a native and life long resident of Luneburg, Germany, derived the formulas for the projection of the sphere using two standard parallels.[2] The Albers projection is a way to project a sphere or ellipsoid onto a cone.[3] It is a projection that is useful for regions that run east to west and that require an equal-area representation.[4] The USGS uses this projection to show the United States (particularly the lower 48 states) or large areas of the United States. This projection is well suited for large countries and is handy for thematic mapping.[5]
All areas will be proportional to the same areas on the earth. Directions are reasonably accurate in limited regions. Distances are true on both standard parallels. Scale is true along standard parallels.[6] Total range in latitude from north to south should not exceed 30–35 degrees.[7] Any keywords for the Lambert conformal conic also apply to the Albers conic.[8]
Sources
- ↑ http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html
- ↑ http://www.geo.hunter.cuny.edu/mp/conic.html
- ↑ Glassner, Andres W. (1993)Graphic Gems Morgan Kaufmann Pub.
- ↑ www.csiss.org/map-projections/Conic/Albers_E_a_Conic.pdf
- ↑ http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html
- ↑ http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Albers_Equal_Area_Conicrange
- ↑ http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Albers_Equal_Area_Conicrange
- ↑ http://idlastro.gsfc.nasa.gov/idl_html_help/Cylindrical_Projections.html
| Authors | Laurie H. |
|---|---|
| Editors | Brian Bunker,Robert McCleary |
| BoK Topics | DN1, CV2, CVG |
| 311 Weeks | 7 |
| Tags | projection, conic |
