Land Boundary Information System
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DOQQ Frequently Asked Questions
I have downloaded DOQQs in JPEG2000 format, but I get an error message that some of them are corrupted when I put them in ArcMap. Why won't they display?
There is a bug in ArcMap 9.1 (and earlier versions) that will only allow 15-17 JPEG2000 images to be put in an ArcMap project. After that, you will get error messages that make it appear as if the images are damaged. The images are fine, however -- the problem is with ArcMap. There is a patch that solves this problem (and this bug is supposed to be corrected in ArcMap 9.2). You can find the patch at www.esri.com. Choose the Support tab, then Downloads from the Support menu. Choose the Patches & Service Packs option on the Downloads page, and then choose the ArcEditor option from the Patches & Service Packs page. The upate you want is ArcGIS 9.1 Service Pack 2.
How can I determine the correct metadata for DOQQs that are in more than one Water Management District? (For example, the Kissimmee quad, q3512, is in multiple Water Management Districts)
For some DOQQs, they fall in a single flight line and thus in a single WMD. The others in fact do fall in multiple flight lines. What you are observing is a “problem” with digital imagery in general. It is entirely possible for those images that fall in multiple flight lines to actually be a blend of pixels from multiple image captures.
In the future we are attempting to limit this problem by dividing the state into 5000 foot cells and assigning specific vendors to specific sets of cells. The vendor will then be responsible for the metadata for those cells. It does not necessarily solve the problem however because the vendor make take multiple days to capture the imagery for a single cell, but the problem of determining which metadata is appropriate is shifted to the vendor (who knows the most about the imagery at this point) and not the end user.
St. Johns WMD imagery was captured by 3001 while the other 4 districts used Earthdata. Both companies used the same specs and camera type so, in theory, the metadata should be very similar with the exception of fly dates (which, again, should be fairly close also).
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