Save Online Data as Raster Image
Global Mapper User
edited July 2014
What is the best way to save a large area (say Northeast USA) but at a close zoom level so the data does not have to re-download each time a new area is worked on?
edited July 2014
That's kind of a big question with many possible answers, probably many of which are not what you are hoping for. To save many of the online sources that are orthophoto layers at high resolution, the storage for something as large as the entire Northeast US would be prohibitively large, not to mention the download time for an area that size. Some of the lower resolution terrain grids would take up much less space and might actually be somewhat practical to work with on that scale however like the NASA ASTER terrain surface or SRTM terrain. However you were to approach the project, you would certainly want to create a tiled output dataset rather than attempting to store the layer as a single or even small group of large files.
What I would recommend in general would be not necessarily exporting the entire region, but when you need a particular area, export just that local area at the desired resolution into a tile set of sizes that make them more manageable to work with, then creating Map Catalog files for them to streamline their loading. Perhaps setting up a tile set export and letting it run overnight or over a weekend if you are looking at large, subregional areas. If you really do need an entire regional dataset at your fingertips, you will likely be looking at a rather sizable hardware purchase for storage, and you would find much greater efficiency of transfer by actually getting the data directly from the source rather than piping it through the WMS feeds. If you can give any more detail on the layers you are interested in and the resolutions you are hoping to work with, we can give you a more nuanced recommendation.
Director of Product Management
Blue Marble Geographics