-------- Original Message --------
Subject:        Re: Lat/long in Google maps
Date:   Wed, 8 Aug 2007 15:38:24 -0500
From:   Nat Case <[log in to unmask]>
To:     Maps, Air Photo & Geospatial Systems Forum <[log in to unmask]>



And I was confused in my initial post: Google MAPS uses Mercator.
Sorry folks., and thanks Zachary for the reference.

--
Nat Case
Hedberg Maps, Inc


Zachary Christman wrote:
>Maps-L wrote:
>>FYI, I think that the Google Earth is using the
>>>Platte Carre projection.
>>
>>Nope, good ol' Mercator. Hence it is conformal at all scales...
>>Actually an application where it makes a lot of sense, since it is
>>mostly used at large scales.

>Just an update, from the horse's mouth (both answers are "correct";
>Plate Carree for display and Mercator for data storage and importing):
>
>http://earth.google.com/userguide/v4/ug_importdata.html
>"A Note About Projections and Datums
>
>Google Earth uses Simple Cylindrical projection with a WGS84 datum for
>its imagery base
>
>   1. Simple Cylindrical (Plate Carree) Projection
>   2. Google Earth Image Base
>
>Typically, the data you import into the Google Earth application is
>created with a specific geographic coordinate system, such as a
>Universal Transverse Mercator (UTM) projection and a NAD27 datum (North
>American Datum of 1927). Each geographic coordinate system may assign
>slightly different coordinates to the same location on the earth. When
>you import data into Google Earth, your data is interpreted according to
>the Google Earth coordinate system.
>
>In the majority of cases, reprojection works as expected. In some
>situations, the transformation might not work properly. In that case,
>you can use a third-party tool to transform your data from its original
>coordinate system into the one used by Google Earth.
>
>The rest of this section provides a brief overview of map projections
>and datums."