Tiled Landsat

holeintheholeinthe Global Mapper UserPosts: 3
edited May 2008 in Downloading Imagery
The LS 7 mosaic hosted by JPL at NASA is very popular data, and according to the message they're now posting, access is now routinely blocked.

(See OnEarth, JPL WMS Server)

Those of us who want to use GM to download this data appear to have a couple of options. One, as has been mentioned in this forum and elsewhere on GM's website, is to use the LS mosaic hosted by USGS instead--which is in fact readily downloadable, and it's nice data. It's just not the same as the JPL data--it's only got one band from the visible-light part of the spectrum, as opposed to three in the JPL OneEarth mosaic.

A second workaround is discussed by JPL at the link above: using their server that has tiled LS7 data. Is this something that I can do through Global Mapper? How? I tried adding the WMS tiled server to the list in GM, which was easy enough, but then I didn't know how to call for the tiled data?

I am eager to try this. Can someone help me find out how to do it?

Thanks

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited May 2008
    Unfortunately the Tiled WMS that the web site speaks of for quicker access is something that requires a lot of programming changes internal to Global Mapper. It is not something that you can get at just by changing the WMS server parameters or anything. We do hope to eventually build-in access to the special tiles to make the Landsat access more reliable.

    Have you tried getting the Landsat imagery from Nasa at https://zulu.ssc.nasa.gov/mrsid/mrsid.pl or perhaps accessing the alternate Landsat7 sources using the File->Open ECW from Web menu command?

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • holeintheholeinthe Global Mapper User Posts: 3
    edited May 2008
    Oops. The NASA imagery on the zulu site that you refer to is the same data that I was referring to erroneously as USGS data. Sorry about that.

    Yes, the zulu mrsid data is easy to download, and it's nice data. But it's false color--near-infrared bands for the R and G channels, plus visible green data on the B channel. This is very useful data, for many purposes. But the LS7 mosaic that GM links to, on the JPL site, is made from 3 natural-color bands on the R, G, and B channels (plus panchromatic sharpening). It's useful for different purposes, particularly display.

    It's not just that one dataset has been "colorized" differently. The 2 mosaics utilize data collected by different sensors on the satellite. One mosaic can't really substitute for the other.

    If you can point us to another "natural color" mosaic, that would be wonderful.

    Thanks very much,
    hole
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited May 2008
    Hole,

    I'll let you know if I find another site with the data processed as you like, or if perhaps we change the Landsat access to use the pre-tiled data which is faster and not blocked.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
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