Difference between revisions of "The National Map"

From PathlossWiki
Jump to: navigation, search
(How to download)
Line 1: Line 1:
'''To go directly to the National Map viewer page, go here: http://viewer.nationalmap.gov/viewer/'''
+
'''Important Note regarding the National Map Viewer'''
  
 +
Because of ongoing changes to the National Map Viewer file formats we recommend using the Multi Resolution Land Characteristics Consortium [[MRLC]] page to download elevation and clutter data in the BIL format. You can also use the prepackaged grid float format described below.
  
 +
The National map view page can be found at http://viewer.nationalmap.gov/viewer/ (Not recommended)
 +
 +
==Information==
 
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/.
 
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/ .
+
==Prepackaged Gridfloat download==
== How to download ==
+
The data can be downloaded at http://viewer.nationalmap.gov/viewer/.
+
 
+
There is online help available by clicking on the '''Tutorial''' link in the header of the page.
+
 
+
* Select the '''Download''' button, located on the top right hand side of the display.
+
 
+
* Select which download template to use.'''.
+
 
+
 
+
[[File:Natmap-1.jpg]]
+
 
+
 
+
* Using the Zoom tool, you can zoom into the area you are interested in.
+
 
+
* Select the area by clicking the template area desired.
+
 
+
 
+
 
+
[[File:Natmap-2.jpg]]
+
 
+
 
+
 
+
* Select the types of data required. Use the '''BIL_16INT''' format for NED data and '''BIL''' for Land COver data.
+
 
+
 
+
[[File:Natmap-3.jpg]]
+
 
+
  
* Select from the available data for the requested area. Use '''Best Avaiable''' and '''Dynamic'''.
+
http://cumulus.cr.usgs.gov/webappcontent/neddownloadtool/NEDDownloadTool.html
  
 +
==Using the Gridfloat data in Pathloss 5==
  
*
+
Click Configure -> Setup GIS Configuration
  
== How to use the seamless NED data with the Pathloss program. ==
+
==Using the seamless NED data with Pathloss 4==
 
Decompress the dataset to its own directory. The dataset is comprised of 16 files…
 
Decompress the dataset to its own directory. The dataset is comprised of 16 files…
  

Revision as of 15:14, 21 December 2012

Important Note regarding the National Map Viewer

Because of ongoing changes to the National Map Viewer file formats we recommend using the Multi Resolution Land Characteristics Consortium MRLC page to download elevation and clutter data in the BIL format. You can also use the prepackaged grid float format described below.

The National map view page can be found at http://viewer.nationalmap.gov/viewer/ (Not recommended)

Contents

Information

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/.

Prepackaged Gridfloat download

http://cumulus.cr.usgs.gov/webappcontent/neddownloadtool/NEDDownloadTool.html

Using the Gridfloat data in Pathloss 5

Click Configure -> Setup GIS Configuration

Using the seamless NED data with Pathloss 4

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

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