-------- Original Message --------
Subject:        Re: Historic Maps in Google Earth
Date:   Tue, 23 Jan 2007 16:21:31 -0800
From:   Matt Fox <[log in to unmask]>
To:     Maps, Air Photo & Geospatial Systems Forum <[log in to unmask]>
References:     <[log in to unmask]>


Hi Dave, just wanted to let you know that there is a better way of posting
large map overlays in Google Earth that involves splitting the image up into
smaller tiles with different resolutions.  As the user zooms in, the higher
resolution tiles will load.  This method allows maps of almost unlimited
resolution to be viewed in Google Earth without making the user download the
entire image.  This only works with Google Earth 4 and high speed internet
is required.  To give you an idea of what's possible, my Sectional Chart
overlay is about 1.5 gigabytes of map images split into 40,000 tiles and
covers the entire US.

Here's a quick example of a Salt Lake Bathymetric map that I recently added.

http://www.fox-fam.com/gefiles/maps/SaltLakeBathymetric/SaltLake.kml

Many more at my website (http://www.topomaps.fox-fam.com/), including

60-minute historic topos of Western US. -
http://www.fox-fam.com/wordpress/?p=18
Los Angeles County 6-minute topos from 1920s -
http://www.fox-fam.com/wordpress/?p=39

Besides topos, have a bunch of others, such as Mars and Moon overlays for
Google Earth, Aeronautical Sectional Charts of entire US, and a bunch of
geologic maps.  Adding more all the time.  I'm always looking for more
public domain maps to add.  Unfortunately most of the map libraries these
days (yours included) do not allow users to download the original images and
only let us view the maps through a web-browser.

Matt








----- Original Message -----
From: "Maps-L" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, January 23, 2007 1:14 PM
Subject: Historic Maps in Google Earth


> -------- Original Message --------
> Subject:        Historic Maps in Google Earth
> Date:   Mon, 22 Jan 2007 19:39:14 +0000
> From:   [log in to unmask]
> To:     [log in to unmask]
>
>
> In my announcement of the latest additions at the Broer Map Library,
> you may recall that I mentioned that we will be making select maps
> available for viewing as a layer in Google Earth.  So far we have
> added about 40 such maps and you may find them here:
>
> http://www.broermapsonline.org/members/gemaps.html
>
> Users can control how visible the map layer is and so they can easily
> compare changes between the historic map and the current situation.
> We will be working on adding additional maps for same locations and
> that would allow a user to compare the changes between map versions in
> addition to satellite photography.
>
> This will be an on-going project for us, but I wanted to share what we
> have done so far.  We've created a help page too if users need
> assistance.
>
> Dave Broer
> Director, Broer Map Library
> http://www.broermaps.org
>