Most of the data by GPS drivin sites I've encountered have big problems moving away from the poles. Which tells me, while the site may be great they really just threw something together and didnt look at the algorithms that could have made their job easier, although just slapping gmaps into a site is easy, it's just not accurate. While some may know this, others may not... ArcMap will not let you use the EPSG codes 4326 or 900913 to do distance calculations. You might think you are but in the background it's transforming them and spitting it all back to you correctly(ish).
What did I figure was the best?... plate carrée.
Info: WGS 84 / Plate Carree is a projected CRS last revised on 11/06/2001 and is suitable for use in World. WGS 84 / Plate Carree uses the WGS 84 geographic 2D CRS as its base CRS and the World Equidistant Cylindrical (Sphere) (Equidistant Cylindrical (Spherical)) as its projection. WGS 84 / Plate Carree is a CRS for Graticule coordinates expressed in simple Cartesian form. It was defined by information from OGP. Origin is at intersection of equator and Greenwich meridian. Note: this is not the same as plotting unrectified graticule coordinates on a computer display using the so-called pseudo Plate Carre method: here the grid units are metres.
| Projected CRS Details | |
|---|---|
| NAME: | WGS 84 / Plate Carree |
| CODE: | 32662 |
| CRS TYPE: | projected |
| AREA OF USE: | World |
| COORDINATE SYSTEM: | Cartesian 2D CS. Axes: easting, northing (X,Y). Orientations: east, north. UoM: m. |
| BASE GEOGRAPHIC CRS: | WGS 84 |
| PROJECTION: | World Equidistant Cylindrical (Sphere) |
| META DATA | |
| REMARKS: |
Origin is at intersection of equator and Greenwich meridian. Note: this is not the same as plotting unrectified graticule coordinates on a computer display using the so-called pseudo Plate Carre method: here the grid units are metres.
|
| INFORMATION SOURCE: | OGP |
| DATA SOURCE: | OGP |
| REVISION DATE: | 11/06/2001 |
Meridians: Equally spaced straight parallel lines half as long as the Equator.
Parallels: Equally spaced straight parallel lines, perpendicular to and having same spacing as meridians
Poles: Straight lines equal in length to the Equator
Symmetry: About any meridian or the Equator
How I got my data into Postgres 9.1 with PostGis 1.5
SELECT AddGeometryColumn( 'public', 'zctas', 'thepoint_lonlat', 32662, 'POINT', 2 );
UPDATE zctas SET thepoint_lonlat = ST_SetSRID(ST_Point( longitude, latitude),4269);
