PriceCollins
Inspector Detector
Reged: 08/10/05
Posts: 1569
Loc: Fairfax, VA, USA
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The exceptional online resources of the Perry-Castaņeda Library of the University of Texas at Austin provide a series of topographic maps created by the US Army Map Service. They date primarily from the 1940s and 1950s, so they are more detailed in areas of military concern during and after World War II. You can see the full TABLE OF CONTENTS. The USGS quadrangles are listed in the USA INDEX.
While the maps are somewhat outdated, they are excellent for locating tiny villages, finding islands which are not visible or named, and obtaining topographic details.
When using them in conjunction with Google Earth, it is often rather difficult to quickly find the specific map which covers an area of interest. This posting is designed to provide both the global area quadrangles and the city maps which show far greater details.
(The download file is only about 112 KB.)
With the addition of eastern Europe, Version 14 provides a set of 3,529 rectangles, with 4,387 clickable links in the icon bubbles which will load the relevent maps in your browser.
- BLUE: World, 2,516 rectangles with links to 3,318 maps, scale = 1 : 250,000
- RED: World, 348 maps, scale = 1 : 1,000,000
- GREEN: Africa, 31 maps, scale = 1 : 2,000,000
- YELLOW: 690 City Maps
have been provided globally. The east Asian region is illustrated here:
Sample: The following area in South Africa shows a large green Africa-36 map (1:2,000,000), three red World maps (SH 35, SH 36, and SI 35 at 1:1,000,000), many small blue quadrangles (1:250,000), and three yellow city maps (Bloemfontein, Durban, and East London).
Edited by PriceCollins (03/24/08 02:40 PM)
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Forkboy2
Cartographer
Reged: 07/16/05
Posts: 431
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Nice. If someone georeferences them, I'll create SuperOverlays and import them into Google Earth.
Matt
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Matt
Google Earth Library
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PriceCollins
Inspector Detector
Reged: 08/10/05
Posts: 1569
Loc: Fairfax, VA, USA
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Forkboy2,
Quote:
Nice. If someone georeferences them, I'll create SuperOverlays and import them into Google Earth.
If you examine them, you will see that the maps are various forms of conical projections, not rectangular Mercator projections. They only approximate projectable images in the equatorial regions, and would not lend themselves to significant orthorectification. Their margins would need to be removed if they were to be used in adjacent pairs, and in some cases copyright issues would have to be addressed.
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Forkboy2
Cartographer
Reged: 07/16/05
Posts: 431
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Quote:
If you examine them, you will see that the maps are various forms of conical projections, not rectangular Mercator projections. They only approximate projectable images in the equatorial regions, and would not lend themselves to significant orthorectification. Their margins would need to be removed if they were to be used in adjacent pairs, and in some cases copyright issues would have to be addressed.
As long as they were all produced by US Government agency, there should not be any copyright issues. You can't scan a US Government document and then claim copyright.
Collars can also be easily removed. I would actually leave the collars in and just make it so only one map can be viewed at a time so there is no overlap issues.
As for projection issues, any decent GIS program should be able to address that. For example here is Geologic Map of the United States that I did for Google Earth. The original map was a 23,000 x 15,000 JPG in conic projection. I georeferenced it and then converted to Geographic projection for GE.
Don't get me wrong, it would be an incredible amount of work to georeference all of these. But what a great resource that would make.
I'd be willing to help out, but it's too much work for one person.
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Matt
Google Earth Library
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Forkboy2
Cartographer
Reged: 07/16/05
Posts: 431
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Sorry I'm replying again before my last reply got approved. But here is a sample to show that it's not all that difficult to import these into Google Earth. This took me about 10 minutes. I first georeferenced to Polyconic Projection. Then converted to Geographic Projection. Then created SuperOverlay. Then uploaded to Server. Would take less time per image if done in batches. I'm willing to do everything but the Georeferencing.
San Francisco Bay AMS Map Test
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Matt
Google Earth Library
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