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Suggestions for exporting large amounts of satellite imagery?

SwoodySwoody Global Mapper UserPosts: 97Trusted User
edited June 2015 in Downloading Imagery
Hi all,

Need help figuring out the best way to download satellite imagery (World Imagery) for a person who will be without internet connection (near the North Pole) for a month. The area covers an approximately 200-300 mile radius. The maps will mostly be used for flight planning. I know I need to tile the imagery, but it is more the resolution and format I am confused about.

Preferably I would like him to view the downloaded maps in Google Earth (which will be offline, of course), since he will be on a Mac and does not have Global Mapper.

I did a export test: (Export > Raster image > JPEG2000) of an area which was approx. 125 square miles, divided into 4 tiles. Each tile exported at around 350MB. It took 7 hours. They opened fine in Global Mapper, but I cannot import or open them in Google Earth (probably because they are so big). So, I tried to resize them in Photoshop, but it would not open them: "Could not complete your request because the file-format module cannot parse the file." I did another test where I downloaded NED maps of the same area as JPEG2000 files. These are only 450KB, so no size issue. They also will not import or open in Google Earth. Aargh!

OK - so then I tried exporting my raster imagery as KMZ. Got a very small area test to work, but trying to export a larger area has been unsuccessful (My box keeps locking up) or it says it will take forever, so hard to test.

Any suggestions on best settings for exporting (large swaths of) satellite imagery at a quality which will be good enough to view landforms, but does not need to be super-detailed?? And in a format which will work in Google Earth (open to other map viewers if need be). I tried screen capture but not good enough resolution, and also not geo-referenced.

Please note I am not a GIS person, so please pardon if this last question is “geo-ignorant”. Why, oh why, can’t I view the North Pole area in Nadir view? It only allows me to view from an angle, which makes it somewhat difficult. In google earth I have no problem with Nadir, but cannot view (that area) in Global mapper this way. (see attachment)

Any suggestions greatly appreciated!
Sara

Screen Shot 2015-06-11 at 3.07.50 PM.png

Comments

  • SwoodySwoody Global Mapper User Posts: 97Trusted User
    edited June 2015
    Hi, correction - near Greenland, not North Pole.....
  • Ice Age MarkIce Age Mark Global Mapper User Posts: 324Trusted User
    edited June 2015
    Hi there,

    If you use an Orthographic projection, with the center Lat/Long values at the center of the view you want, it should appear as though you are looking straight down. Don't know about your export issue.

    Regards,

    Mark
  • SwoodySwoody Global Mapper User Posts: 97Trusted User
    edited June 2015
    Hi Ice Age Mark,

    Thanks for the suggestion. I tried to change projection (under configuration) for my workspace, but it made the computer lock up. Also tried creating a new workspace with no data, and Orthographic projection. Same freeze up. Satellite imagery momentarily appeared, but was very slanted and weird. Darn it! Thanks again.....
  • bmg_bobbmg_bob Global Mapper Programmer Posts: 2,278
    edited June 2015
    Hi Swoody,

    I recommend that you contact Blue Marble Geographics support (geohelp@bluemarblegeo.com) for these issues. For the hang when you switch projections, please provide a detailed description of your workflow for downloading the imagery (a screen capture of the Online Data Source options would also help) and changing the projection so the support team can try to reproduce the problem. Then can also help with your original question -- feel free to link back to your forum post.

    Cheers,

    Bob
  • SwoodySwoody Global Mapper User Posts: 97Trusted User
    edited June 2015
    Thanks Bob. I do need to figure the why changing to Orthographic projection doesn't work, but right now my main concern is figuring out how to download this imagery. I started a raster download last night, of a small area, and it was useless. Came in this morning to a spinning ball, nothing downloaded. aarhg! Does anyone at least know of a site, kind of like "National Map" that I can just go and download or buy maps for this area?
  • SwoodySwoody Global Mapper User Posts: 97Trusted User
    edited June 2015
    I have just figured out that the area is technically part of Canadian territory, so that helps narrow it down!
  • Ice Age MarkIce Age Mark Global Mapper User Posts: 324Trusted User
    edited June 2015
    This site may have what you need.

    Geospatial Data Extraction | Natural Resources Canada

    Regards,

    Mark
  • SwoodySwoody Global Mapper User Posts: 97Trusted User
    edited June 2015
    Thank you, Mark!
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