[Geoinquiets Barcelona] comparar zones

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[Geoinquiets Barcelona] comparar zones

Raf Roset
Per comparar superfiícies a Google Maps http://mapfrappe.com/index.html?show=2385 (no som res!)

Raf
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Re: [Geoinquiets Barcelona] comparar zones

Alexandre Nobajas
Com diu a baix, comparar superfícies amb una projecció de tipus Mercator és agosarat. Però com a divertimento està molt bé!

Shape Distortion

If you draw the outline at a given latitude in the Reference map, and then view the outline at a different latitude in the Comparison map, the relative orientation of the marker positions will be distorted. This distortion occurs for two different reasons.

First, Google Maps uses a Mercator projection for its maps. By design, this projection distorts distances at different latitudes. Distances are magnified at higher latitudes.

Second, my calculation of comparison marker positions attempts to preserve true distances between markers. These calculations account for the fact that units of longitude have different lengths depending on latitude. The calculations somewhat reverse Mercator distortions of horizontal distances, but not vertical distances.



--- On Wed, 2/23/11, Raf Roset <[hidden email]> wrote:

From: Raf Roset <[hidden email]>
Subject: [Geoinquiets Barcelona] comparar zones
To: [hidden email]
Date: Wednesday, February 23, 2011, 11:05 AM

Per comparar superfiícies a Google Maps http://mapfrappe.com/index.html?show=2385 (no som res!)

Raf

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