Import from Web
GMS, SMS, and WMS make use of the Import from Web feature.
The Import from Web feature connects to the internet to download free data – images, elevation data etc. If able to connect to the internet, this is an easy and convenient way to acquire this type of data.
The data is made available for free by various entities who provide web services. Each of the XMS programs has a number of available data types they can retrieve.
It should be noted that the Import from Web feature links to external internet sites which can change without warning. For example, historically the XMS programs retrieved data from the TerraServer site which was terminated. The termination or modification of an online source may result in invalid links in the XMS program until the links can be corrected.
The Import from Web command is accessed in a number of ways. These include:
- From the File menu.
- From the Get Data From Map macro (WMS only).
- From the Get Data tool (SMS and WMS).
In the first two options the XMS program brings up a map locator tool (Virtual Earth) that allows selecting (via pan and zoom) an area of interest and download data for this area (as shown below).
The Get Data tool is available from the data toolbar when the XMS application is using a global projection. When this tool active in SMS or WMS, graphically select a rectangle in the graphics window and download data inside this rectangle.
The XMS programs also have a Get Online Maps tool which can be used to get dynamic raster data, such as image or raster elevation data. The dynamic map is updated automatically when zooming in or out in the graphics window. Any instance of a dynamic map on the screen can be downloaded by right-clicking on the map and selecting the Export command. This command will download the map to the computer.
Available data sources include:
- World Imagery More Info
- World Street Maps More Info
- World Topo Maps More Info
- USA Topo Maps More Info
- Worldwide Elevation Data (Variable Resolution)
- NLCD and CORINE (European) Land Cover data
- USA Flood Hazard Zones
- USA Base Flood Elevation Lines
- Land Use Shapefiles
- STATSGO and SSURGO Soil Type Shapefiles
- Harmonized World Soil Database v 1.1
- Global Land Cover
Elevation (NED, ASTER, and SRTM) Data
- NED data contains the best available raster elevation data of the conterminous United States, Alaska, Hawaii, and territorial islands. NED data are not available for other areas.
- ASTER and SRTM data are available for most of the earth's surface. The ASTER dataset is reliable and high-quality.
Most of the imagery (World Imagery, Street Maps, Topo Maps, and OpenStreetMap.org data) are available for anywhere on the earth. Some imagery, such as US Topo Maps, are only available for areas of the United States. Besides downloading these images using the Import from Web command, these images can be read as online maps that change resolution dynamically depending on the location.
Land Cover Data
- The 100 m Resolution CORINE dataset (raster) is available for anywhere in Europe.
- The 30 m NLCD dataset (raster) is only available for the conterminous United States.
- The Land Use Shapefile dataset is available for the entire United States.
- The Global Land Cover dataset is available in 2 degree by 2 degree blocks for the entire world. The following steps were used to convert the Land Use data to a format that can be used for WMS hydrologic modeling:
- Go to the European Space Agency site to download land use data.
- Download the .zip file Globcover2009_V2.3_Global_.zip and unzip this file on the computer.
- Open GLOBCOVER_L4_200901_200912_V2.3.tif in a GIS (such as ArcMap) and convert it to an ESRI raster file. Trim the raster as needed, then convert the raster to a shapefile.
- Convert the file Globcover2009_Legend.xls to a *.dbf file and join this file with the shapefile values to get the land use names and IDs.
- SSURGO soil datasets are available for all available SSURGO survey areas in the United States (as of August 2013).
- A STATSGO soil dataset is available for every state in the United States.
- Data from the Harmonized World Soil Database are available in 2 degree by 2 degree blocks for the entire world. The WMS developers used the following steps to convert the soil data to a format that can be used for WMS hydrologic modeling:
- Download and install the Harmonized World Soil Database program from the Harmonized World Soil Database web site.
- Launch the HWSD Viewer on the computer. The soil data will be copied to the folder c:\program files (x86)\HWSD_v<xxx>\Data where <xxx> is the version of the viewer downloaded. The program may also be installed in c:\program files\<...> if running a 32-bit version of Windows. The following files are contained in this folder:
- The HWSD Raster *.zip file.
- The HWSD DBF file.
- The HWSD_META DBF file.
- Copy the files in the data folder to a writable location on the computer and unzip the HWSD Raster *.zip file.
- Open the .bil file in ArcMap and convert the *.bil file to a shapefile using the IDs.
- Join the HWSD DBF file with the IDs in the shapefile.
- Join the attribute IDs with the HWSD_META DBF file. This gives a shapefile with the soil IDs and various soil attributes that can be used for hydrologic modeling in WMS.
Note that more vector-based soil and land use datasets are available; Contact Aquaveo if interested in adding data from a specific area to the list of available land use or soil data that can be downloaded. A comprehensive list of soil and land use data available for download is located here.
TerraServer images are no longer available because this web service has gone offline.
Using the Import from Web Command
Using the Import from Web command will bring up a number of dialogs as described in the next sections.
Virtual Earth Map Locator
When the Import from Web command is invoked from a menu or macro, the Virtual Earth Map Locator dialog is launched. The dialog has the following options.
- Virtual Earth Map Locator: Use the map in this dialog to go to the location of interest.
- Search using latitude/longitude coordinates or place name.
- Zoom In or Zoom Out using the controls or the mouse wheel.
- Pan by clicking and dragging. It's also possible to enter the latitude and longitude to jump to a specific location.
- Use the drop-down menu to switch between different views. Available views include:
- National Geographic
- Dark Gray
- Imagery (Clarity)
- Imagery (Firefly)
- Shaded Relief
Using the Add Online Maps menu command or macro will also launch the Virtual Earth Map Locator, but only the first time the command or macro is used in a project. The dialog will not appear if dynamic images are already in the project.
Additional Import Dialogs
Once the region for data download is defined, a series of dialogs appear which defines the data to be downloaded. These dialogs include:
- Data Service Options
- Here select which type of data of interest.
- Next a dialog asks where to save the data. It is only necessary to specify one file name, even if having selected more than one type of data in the previous dialog. The files will all be given the same prefix but different suffixes.
- Confirm File Creation
- A dialog may ask to confirm creating the files.
- Initialize Connection
- The following dialog is shown while the connection is being made.
- Select Scale
- Smaller numbers (larger scales) will result in better resolution, but longer download times.
- This dialog reports the download progress. If Abort is clicked, the image will exist but will be only that portion that has been downloaded so far.
Steps will repeat for each data type selected.
After everything is finished, the data (images etc.) will appear in the Project Explorer.