Mapping Center

This post, is to announce the release of a map template for historical GIS called Historical GIS:  Boston 1775. If you’ve never given historical GIS a second, or a first thought, you might find the contents interesting and maybe even applicable to your work. Consider that the vast majority of GIS data is historical, even if it’s only a few minutes old. Read More...

This post is to announce the Map Templates Resource Center. Map templates are useful examples. Each map template is a kit that contains a collection of resources needed to transfer a specific map’s design and ArcGIS implementation to you.

These templates are not the template map documents that you might have saved as an .MXT file. Instead these templates are .ZIP files that typically include: Read More...

You will often be prompted to select the geographic transformation when you are projecting data or setting the projection of a data frame in a map document. Here are some concepts that might help you understand what this is all about AND how to make the right selection.

First, "geographic coordinates" are expressed in terms of latitude and longitude. "Latitude" is the north-south angular measure from the equator to the point of interest. "Longitude" is the east-west angular measure along the equator from the prime meridian to the point of interest's longitude. Assuming that the earth is a sphere, geographic coordinates are determined relative to the center of the sphere - these coordinates are called "geocentric latitude and longitude". (See the figure at the right; all figures are from Map Use: Reading and Analysis, 6th edition, ESRI Press.) Read More...

Someone pointed out to me that ESRI's CEO, Jack Dangermond recently did an interview that focused on web mapping. You can read and hear it here: http://radar.oreilly.com/2009/04/jack-dangermond-interview-web-mapping.html. Read More...