Difference between revisions of "USGS SDDS"

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(How to use the seamless NED and SRTM data with the Pathloss program.)
(How to use the seamless NED and SRTM data with the Pathloss program.)
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== How to use the seamless NED and SRTM data with the Pathloss program. ==
 
== How to use the seamless NED and SRTM data with the Pathloss program. ==
Decompress the dataset to its own directory. The dataset is comprised of 10 files…
+
Decompress the dataset to its own directory. The dataset is comprised of 16 files…
  
13692282.aux
+
* *.aux
13692282.bil
+
* *.bil
13692282.bil.aux.xml
+
* *.bil.aux.xml
13692282.blw
+
* *.blw
13692282.hdr
+
* *.hdr
13692282.prj
+
* *.prj
13692282.stx
+
* *.stx
meta1.html
+
* meta1.html
METADATA.dbf
+
* METADATA.dbf
METADATA.prj
+
* METADATA.prj
METADATA.shp
+
* METADATA.shp
METADATA.shx
+
* METADATA.shx
Metadata.xml
+
* Metadata.xml
NED DataDictionary.pdf
+
* NED DataDictionary.pdf
NED_Release_Notes_June10.pdf
+
* NED_Release_Notes_June10.pdf
output_parameters.txt
+
* output_parameters.txt
  
 
 
 
 
 
 
{| border =0
 
|-
 
|*.BIL
 
|METADATA.DBF
 
|-
 
|*.BLW
 
|METADATA.PRJ
 
|-
 
|*.HDR
 
|METADATA.SHP
 
|-
 
|*.PRJ
 
|METADATA.SHX
 
|-
 
|*.STX
 
|METADATA.TEX
 
|}
 
  
 
In Version 4.0 make sure to use NED CONUS for data in Alaska. Do not use NED Alaska.
 
In Version 4.0 make sure to use NED CONUS for data in Alaska. Do not use NED Alaska.
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The SRTM data uses the WGS84. NAD83 and NAD27 Coordinates are transformed automatically.
 
The SRTM data uses the WGS84. NAD83 and NAD27 Coordinates are transformed automatically.
  
In the Pathloss program click '''''Configure''''' – '''''Terrain Database''''' and depending on the dataset select either '''''NED CONUS''''', '''''NED Alaska''''' or '''''SRTM''''' from the drop down list.  
+
In the Pathloss program click '''Configure''' – '''Terrain Database''' and depending on the dataset select either '''NED CONUS'''or '''NED Alaska''' from the drop down list.  
  
Click '''''Setup Primary''''' (or Secondary depending on your selection).  
+
Click '''Setup Primary''' (or '''Setup Secondary''' depending on your selection).  
  
 
Click the file button and browse to find and load the file with the BIL extension. The program is now setup to use the selected BIL file.
 
Click the file button and browse to find and load the file with the BIL extension. The program is now setup to use the selected BIL file.

Revision as of 13:03, 3 August 2010

To go directly to the NED download page, go here: http://seamless.usgs.gov/


The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey. NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data. NED has a resolution of one arc-second (approximately 30 meters) for the conterminous United States, Hawaii, and Puerto Rico and a resolution of two arc-seconds for Alaska. More info can be found at http://gisdata.usgs.net/NED/.

SRTM 30m and SRTM 90m data is also available from the the USGS Seamless Distribution site. Information on the SRTM data can be found at http://srtm.usgs.gov/ .

How to download

The data can be downloaded at http://seamless.usgs.gov/. Click on the View and Download United States Data graphic to go to the download page.

There is online help available by clicking on the Tutorial link in the header of the page.

  • Select the Download tab on the right hand side of the display.
  • Check the boxes for NED, 1/3 NED or 1/9 NED.


Sdds select.JPG


  • Using the Zoom tool, you can zoom into the area you are interested in.
  • Define the area by either clicking the Define Download Area by Coordinates tool under Download tool group.


Sdds download.JPG


  • If using the Define Download Area by Coordinates, a dialog will appear that is used to define an area for download. (The example shown is for a 1X1 degree block)


Sdds define.JPG


  • Once the area is defined you will be taken to the download page. You will need to click "Modify Data Request" and change the format to the BIL_16INT format. Click Save Changes & Return to Summary.


  • Click Download. You will be prompted to save the file once it is ready for download

How to use the seamless NED and SRTM data with the Pathloss program.

Decompress the dataset to its own directory. The dataset is comprised of 16 files…

  • *.aux
  • *.bil
  • *.bil.aux.xml
  • *.blw
  • *.hdr
  • *.prj
  • *.stx
  • meta1.html
  • METADATA.dbf
  • METADATA.prj
  • METADATA.shp
  • METADATA.shx
  • Metadata.xml
  • NED DataDictionary.pdf
  • NED_Release_Notes_June10.pdf
  • output_parameters.txt


In Version 4.0 make sure to use NED CONUS for data in Alaska. Do not use NED Alaska.

The NED (CONUS) data uses the NAD83. NAD27 Coordinates are transformed automatically.

The SRTM data uses the WGS84. NAD83 and NAD27 Coordinates are transformed automatically.

In the Pathloss program click ConfigureTerrain Database and depending on the dataset select either NED CONUSor NED Alaska from the drop down list.

Click Setup Primary (or Setup Secondary depending on your selection).

Click the file button and browse to find and load the file with the BIL extension. The program is now setup to use the selected BIL file.