|The Newsletter of the Minnesota GIS/LIS Consortium|
Table of Contents
MN GIS/LIS Consortium
From the Chair
ArcGIS 9 Workshop
2007 Conference in Rochester
Call for Polaris/Lifetime Nominations
NAIP as a Web Mapping Service
By Andrew J. Lister, USDA Forest Service, Northeastern Research Station, Newtown Square, Pennsylvania
NAIP imagery consists of recent (~2003+) imagery that is collected over much of the country. It is available from the NRCS on DVDs. Thanks to Greg Liknes, who discovered this website, we can now get screenshots of the NAIP imagery holdings directly over the web, without having to deal with DVDs. Not all of the NAIP imagery is currently available this way, but large chunks are. The older DOQQs are available as well. The general site for accessing Web Mapping Services at NRCS is http://gdwweb1.ftw.nrcs.usda.gov/
The way to use the NAIP photos in Arc 9 (and maybe a similar way in Arc8, but you should really install Arc9 -- it's worth it!) is to choose add data, then choose "gis servers", and choose "add ArcIMS servers". When it asks you for the server's URL, put in the above website (http://gdw.apfo.usda.gov), and choose "get list". Choose the NAIP data you want (you can check several UTM Zones). Once you hit ok, that server will be listed in your server list. Double-click it, and then you can choose the UTM zone you want. When you load this, you will quickly see that you have the entire UTM zone's NAIP mosaic accessible. The quality of the images is the same, as far as I can tell, as the one found on the DVDs. It's not clear that they actually have loaded every new NAIP image onto this map service, but there are large parts of the holdings.
There is some chance you have to have the data frame set as wgs84 or decimal degrees nad83 for this to load correctly; you can try different projections if you're brave.
The forestry applications of this include: prefield reconnaissance, very quick and easy checking of classification results (e.g., forest/nonforest, vegetation type, etc.), and zooming into plots that seem to have strange data (giant trees? clearcut?). RSAC had been considering putting together an imagery server for the NAIP imagery -- does this change any of those plans? This is a really huge breakthrough!
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