Projections
Geographic (Lat/Lon)
Not a true projection. Treats latitude and longitude as a square grid.
Universal Transverse Mercator (UTM)
A mapping system commonly used by the USGS for quadrangle maps. All data used in a single map must be in the same UTM zone. The UTM coordinate system is used for the Texas Reference Frame.
Texas Centric Mapping System/Lambert Conformal (TCMS/LC)
A mapping system that is optimized for mapping the entire state of Texas within a single dataset. Conformal projections are true to shape but are not necessarily appropriate for measuring area and distance.
Projection | Lambert Conformal Conic |
Spheroid | GRS 80 |
Datum | North American Datum of 1983 (NAD83) |
Longitude of Origin | 100 degrees West (-100) |
Latitude of Origin | 18 degrees North (18) |
Standard Parallel #1 | 27 degrees 30 minutes (27.5) |
Standard Parallel #2 | 35 degrees (35) |
False Easting | 1,500,000 meters |
False Northing | 5,000,000 meters |
Units of Measure | meters |
Texas Centric Mapping System/Albers Equal Area (TCMS/AEA)
A mapping system that is optimized for mapping the entire state of Texas within a single dataset. Equal area projections allow areal measurements and are commonly used for thematic maps.
Projection | Albers Equal Area Conic |
Spheroid | |
Datum | North American Datum of 1983 (NAD83) |
Longitude of Origin | 100 degrees West (-100) |
Latitude of Origin | 18 degrees North (18) |
Standard Parallel #1 | 27 degrees 30 minutes (27.5) |
Standard Parallel #2 | 35 degrees (35) |
False Easting | 1,500,000 meters |
False Northing | 6,000,000 meters |
Units of Measure | meters |
For more information on map projections, please see the USGS Map Projections Poster.