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Frequently Asked Questions
General Questions Orthoimagery
Where Do I Find... Coordination Questions
Coordinate System Questions GIS Certification Questions
Digital Elevation Model (DEM) Add a New Question
Digital Raster Graphic (DRG)
Digital Orthophoto Quadrangles
General Questions
Graphic of the Geospatial Enterprise Office
Geospatial Enterprise Office
Is your data in the public domain?
Yes, but be sure to read our disclaimer statement prior to downloading data. This product is for informational purposes and may not have been prepared for, or be suitable for legal, engineering, or surveying purposes. Users of this information should review or consult the primary data and information sources to ascertain the usability of the information.
Does that mean the data is free?
Yes, the data off our site is free to download and use.
Can you plot data for me?
We are not set up to make maps for the public.
I do not have GIS software, is there a way I can still use your data?
  • Yes. There is a free software package called ArcExplorer that can be downloaded and used to make maps with our data. The software is put out by ESRI and can be downloaded from their Web site at ESRI.
  • If you only want access to the database portion of our data the shapefiles each have a .dbf file in them. This file is a dbase compliant database file.
  • Our ArcIMS site does not require GIS software, but it does not work with all browsers. It has been tested with Internet Explorer Version 6 and later, Netscape version 7 and later and Mozilla 1.1 and later.
Why doesn’t the data I downloaded line up with my data?
Our data may not line up with your data if it is in a different projection or at a different scale (resolution). With the exception of the 30 M DEM data, all the data on our Web site is projected using the Oregon Lambert Coordinate Reference System. Problems may also be caused by errors in either your data or our data.

Where Do I Find...
Is there an official process in place for naming geographic features in Oregon ?
Yes, information can be found at Oregon Geographic Names Board.
Do you have city or county road themes?
The best data we have for local roads is the 1:100,000 scale 2000 Census Roads theme.  Individual Cities and Counties will have more accurate data.
Where do I find GIS data from the USFS or the BLM?
Data for the USFS and BLM can be found at USFS and BLM.
BLM data can also be found at BLM Internet GIS Sites .
Is there some place where I can download Assessor Maps for Oregon?
Yes. You can go to ORMAP.
 
 

Coordinate System Questions
What coordinate system do you use?
With the exception of the 30 M DEM data, all the data on our Web site uses the Oregon Statewide Lambert Coordinate Reference System.  
How do you convert data to Oregon Lambert?
File downloads are available on the Spatial Data Library File Format  web page.

Digital Elevation Model (DEM)
If the DEMs are not in the Oregon Lambert what is the coordinate reference system?
They are UTM NAD27 with vertical units in reference to National Geodetic Vertical Datum of 1929 (NGVD 29).
The DEM files have no file extension. How do I use them?
Simply add a .dem extension to the file prior to importing.
Can I import DEMs into ArcView?
You need to have the Spatial Analyst extension in order to import DEMs into ArcView.
I have Spatial Analyst, but I still am not able to import the DEM file.
ArcView Spatial Analyst limits the number of characters themes can have in their names.
Find DEM Data

Digital Raster Graphic (DRG)
What are DRGs?
DRG is an acronym for Digital Raster Graphics. Digital Raster Graphics are scanned images of the USGS Topographic Quad maps. Our site contains DRGs at various scales.
What are the numbers the data is tiled by and how can I find the quad I want?
The numbers are the Ohiocode. These numbers uniquely identify each quad in the United States. Ohiocode Quad Names (doc)

Digital Orthophoto Quadrangles
What are the numbers the data is tiled by and how can I find the quad I want?
The numbers are the Ohiocode. These numbers uniquely identify each quad in the United States. To look up the Ohiocode for a specific quad name, click here: Ohiocode Quad Names (doc)
I downloaded a DOQ file from your Web site, but it is not showing up where I expected .
You have to download both the .sid file and the .sdw file. If you did not download the .sdw file it will show up in the wrong location. If you did download the .sdw file, check your file. Internet Explorer adds a .txt extension to .sdw files. If you have a filename .sdw.txt, simply remove the .txt ending and the file will operate properly.
Where can I get the DOQ files in their native tiff format?
Tiff formatted DOQ can be purchased from the USGS EROS Data Center.
Why are your DOQs in MrSID format?
Individual DOQs range between 150 and 200 mb. They were put into MrSID format in order to allow for Internet access to the files.

Orthoimagery
What is the latest date for statewide orthoimagery?
Statewide orthoimagery for Oregon was collected in 2005 and may be viewed and downloaded via the Oregon Imagery Explorer.
 
Digital Ortho Quads (DOQs) from 1995 and 2000 are available from the GEO Spatial Data Library  or the  Orthoimagery web page.

Coordination Questions
Can GIS organizations coordinate acitivities through GEO ?
Yes, we publish a statewide calendar on our Web site where you can schedule events. 
GIS Calendar

GIS Certification Questions
Ten Certification Questions (pdf)
Add a New Question
Have a new question?
 
Page updated: April 08, 2008

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