USGS Open-File Report 2009-1089

Digital data from the Great Sand Dunes and Poncha Springs aeromagnetic 
surveys, south-central Colorado

Drenth, B.J., Grauch, V.J.S., Bankey, Viki, and New Sense Geophysics, Ltd.

This report contains digital data, image files, and text files describing 
data formats and survey procedures for two high-resolution aeromagnetic surveys 
in south-central Colorado:  one in the eastern San Luis Valley, Alamosa 
and Saguache Counties, and the other in the southern Upper Arkansas Valley, 
Chaffee County. In the San Luis Valley, the Great Sand Dunes survey covers a 
large part of Great Sand Dunes National Park and Preserve and extends south 
along the mountain front to the foot of Mount Blanca.  In the Upper Arkansas 
Valley, the Poncha Springs survey covers the town of Poncha Springs and vicinity.
The digital files include grids, images, and flight-line data.  

The data files and information about their formats and use are organized into 
three folders (directories) as follows. Files pertaining to this report are 
contained in the "report" folder; files pertaining to the gridded data and 
images are contained in the "grids" folder; files pertaining to the flight-line 
data are contained in the "linedata" folder; and files pertaining to the color 
shaded-relief images are contained in the "images" folder.  In each folder, 
ASCII files with the extension "txt" describe the format and contents of the 
data files.  Read the "txt" files before using the data files.

To begin, read the file "sdreport.pdf" in the "report" folder.  This report lists 
and describes the files available in the other folders.  To view this report, 
you need an Adobe Acrobat reader, which can be downloaded 
at no cost through http://www.adobe.com/.  Next, open the report folder and 
double-click on the sdreport.pdf icon to open the report.  Refer to the 
built-in help system in Adobe Acrobat Reader for assistance with commands.  
                       
Disclaimer

This report has not been reviewed for conformity with U.S. Geological Survey 
editorial standards and stratigraphic nomenclature.

This publication is prepared by an agency of the United States Government. 
Reference to any specific commercial product, process, or service by trade name, 
trademark, manufacturer, or otherwise does not necessarily constitute or imply 
its endorsement, recommendation, or favoring by the United States Government 
or any agency thereof.  

System Requirements

MAC OS X

Adobe Reader 7.0 Macintosh
  PowerPC G3, G4, G5 processor
  Mac OS X v.10.2.8 or higher
  128 MB of RAM
  80 MB of available hard disk space (110 MB required for the full version)
  800 x 600 screen resolution

Adobe Reader 6.0.x Macintosh
  G3 or faster processor
  Mac OS X v10.2.2 or higher
  32 MB of RAM (64 MB recommended)
  70 MB of available hard disk space
  800 x 600 screen resolution

WINDOWS

Adobe Reader 7.0 MS Windows
  Pentium-class processor
  Windows XP Professional or Home Edition with SP1 or SP2, or Tablet PC 
  Edition; Microsoft Windows 2000 with Service Pack 2 (SP2)
  128 MB of RAM
  90 MB of available hard-disk space for the full version
  800 x 600 monitor resolution

Adobe Reader 6.0 MS Windows
  Pentium-class processor
  Windows XP Professional, Home, or Tablet PC Edition; Windows Me; 
  Windows 2000   Professional SP2; Windows NT   Workstation 4.0 SP6; 
  Windows 98 Second Edition
  32 MB of RAM (64 MB recommended)
  80 MB of available hard disk space
  800 x 600 monitor resolution