Monday, January 25, 2010

Hood GIS Files?

Today:

Spent a while today downloading GLIMS glacier outlines for Hood and figuring out how to transfer the non-projected files I downloaded into GIS. With some help from an email to Bruce Raup I figured it out. According to the metadata all the outlines (which are in red in the kml google earth version to the right) were created by Andrew Fountain. What confuses me is that I think he created outlines for snowfields as well but the data either indicates “glacier outline” or “rock outline” in the meta data. He has labeled the metadata according to the major glacier names such as “elliot”. Should I stick with just the major glacier outlines or keep all the red polygons as you can see to the right. I also finally got things working with Arc Globe today so I was able to put the LiDAR DEM in as the elevation source with the hillshade on top of it. Below to the right is a quick image I made showing Fountain’s polygons for the “glaciers” with the blue representing the 1987 band ratio image with a threshold of .3 cropped to within those polygons.

This is just a start and I’m still working on cropping a few things and getting the projections perfect. I’m going to try to grab a recent NAIP from Watershed (hopefully they have one) of Hood that I’ll drape over top the hillshade to figure out which polygons of Fountain’s appear to be snow fields or glacier or if there is even anything there anymore.

Questions:

Do you know of any place for me to get any more glacier outlines for Hood rather than GLIMS which I’ve done? Should I email Andrew Fountain to see if he has any newer ones or different ones than the ones I have? Also, would it be possible for me to get ASTER or SPOT images for 1987, 1992, or 2005? It may help to clarify some things if I had a higher resolution imagery.

1 comment:

Jonathan Ellinger said...

Anne
Jon,

The glacier outlines for Mt. Hood are based (I think) on digitized USGS maps. They are not accurate. You should email Andrew Fountain and ask if he has more up-to-date versions of glacier outlines for Mt. Hood.

ASTER wasn't functional until 2000 -- they were trying to collect imagery every year but not sure they have 2005. Check the ASTER archive. You could try SPOT but I haven't worked with it that much. Could be interesting to see if it's better than Landsat.

For the missing years of interest, are they considered low, medium or high snow years? If they are not low snow years with early melt out then you wouldn't use them anyways.
Thursday, January 28, 2010 - 10:44 AM