GIS Tools

ASF ArcGIS Desktop SAR Toolbox

ASF has developed a Toolbox for use with either ArcGIS Desktop or ArcGIS Pro, containing tools that perform geoprocessing tasks useful for working with Synthetic Aperture Radar (SAR) data. The tools were designed to be used with Radiometric Terrain Corrected (RTC) SAR datasets, but several of the tools have the potential to be used with a variety of rasters, including non-SAR datasets.

The Toolbox is distributed as a zipped archive including the .pyt Toolbox script and associated .xml files. There is an XML file for the toolbox itself and one for each of the tools it contains. These XML files contain the metadata displayed in the item descriptions and tool help windows, and must be kept in the same directory as the Python Toolbox (.pyt) file, or the information they contain will no longer be accessible to ArcGIS.

The current Toolbox contents

  • Unzip Files Tool assists in file management when downloading .zip files from ASF. This tool could be used to extract to a specified location any zip files with an additional internal directory containing the individual files. The tool deletes the original zip files once they are extracted, and is especially helpful when dealing with filenames that are so long that they are beyond the maximum allowed in default Windows unzip utilities.
  • Scale Conversion Tool allows easy conversion of pixel values in calibrated SAR datasets (such as RTC rasters) from power or amplitude scale into power, amplitude or dB scale. This is an application specific to SAR data values.
  • Reclassify RTC Tool generates a raster that includes only those pixels below a user-defined threshold value, and is designed for identifying water pixels. This tool could be used for any application where the user is interested in identifying values below a given threshold.
  • Log Difference Tool compares two rasters by calculating the log difference on a pixel-by-pixel basis to identify areas where backscatter values have changed over time. This tool could be used to compare the pixel values of any two single-band rasters; it is not specific to SAR data.

Prerequisites

  • Users must have either ArcGIS Desktop (ArcMap) or ArcGIS Pro installed and licensed on their computer. The Toolbox has been tested with Desktop versions 10.6.1 and 10.7.1 and Pro versions 2.4.2 and 2.5, but it may work with earlier versions as well.
  • Note that several of the tools require the Spatial Analyst extension. Users who do not have licensing for this extension in ArcGIS will not be able to use many of the included tools.

To install the Toolbox

  • Download the zip file and extract the contents to any directory accessible by the computer running ArcGIS.
  • Ensure that the Spatial Analyst extension is licensed and enabled.
    • ArcGIS Desktop  Click on the Customize menu in ArcMap and select Extensions… Check the box next to Spatial Analyst and click the Close button at the bottom of the Extensions window. If you are unable to check this box, you do not have access to the Spatial Analyst extension and will not be able to make use of tools requiring this extension.
    • ArcGIS Pro  Click on the Project tab and select the Licensing tab. In the list of Esri Extensions, scroll down to verify that the Spatial Analyst is licensed and enabled. If it is not, an organization administrator will need to enable the extension in your user account. If your organization does not have a license available for you to use, you will not be able to make use of tools requiring this extension.

To use the Toolbox

  • In the ArcMap Catalog window or the ArcGIS Pro Catalog pane/view, navigate to the directory containing the toolbox (create a new folder connection if necessary).
    • To open the Catalog window in ArcMap, click on the Windows menu and select Catalog. To open the Catalog pane or view in ArcGIS Pro, click the View tab and click on either the Catalog Pane or Catalog View button.
    • Note that if you explore the extracted contents of the zip file outside of the ArcGIS environment, the directory will contain one .pyt file and a number of .xml files. In the ArcGIS Catalog window/pane/view, only the Toolbox is displayed, and when it is expanded, all of the Tools contained in the Toolbox script are displayed. The XML files are automatically referenced when ArcGIS requires the information they contain, and do not appear as additional files in the ArcMap Catalog environment. The XML files must remain in the same directory as the .pyt file, and their filenames should not be changed.
  • Double-click the ASF_Tools.pyt file to display the Tools (Scripts) included in the toolbox.
  • Double-click on a Tool (displayed with a Script icon) to launch the dialog box or geoprocessing pane, as you would for any other ArcGIS Tool/Script.
  • In ArcMap, click on the Show Help button at the bottom of the tool window to see more information about the tool and helpful tips specific to each parameter. In ArcGIS Pro, hover over the blue question mark at the top of the geoprocessing pane or the blue i icon next to each parameter to display this information.
  • In ArcMap, click on the Tool Help button at the bottom of the Help pane to open another window that displays most of the contents of the tool’s Item Description. In ArcGIS Pro, click on the blue question mark at the top of the geoprocessing pane to open the full tool description in a browser window.
  • Enter the parameters as prompted and click the OK button to execute the tool.
  • Note that output products are not automatically added to a project by default. You must navigate to them in the Catalog window/pane/view (or using the Add Data dialog) and add them to your project if desired.

Tool Help

The XML files included in the zip file are accessed when a user views the metadata for the toolbox, individual tools, or even different fields within the tool dialog. 

  • ArcGIS Desktop
    • The xml metadata is displayed in the Item Description for the toolbox or any of its constituent tools in the ArcMap Catalog window.
      • Right-click the tool in the Catalog window and select Item Description to view it.
    • The information can also be found in the Description tab for the toolbox and each tool in ArcCatalog.
    • Portions of the xml contents are displayed as appropriate in the tool dialog box when a tool is launched in ArcMap.
      • Click on the Show Help button in the tool dialog box to display helpful tips about the tool and each field in the dialog box.
  • ArcGIS Pro
    • The xml metadata is displayed in the Metadata tab in the Catalog view.
      • Right-click a tool in the Catalog pane and select View Metadata to open the Metadata tab for the item in the Catalog view, OR
      • Open the Catalog view directly to navigate to the tool and select the Metadata tab.
    • Portions of the xml contents are displayed as appropriate in the tool dialog pane.
      • Hover over the blue question mark at the top of the tool pane to view the tool description summary.
      • If you click the question mark, it will open the full tool description in a browser window. The formatting is not as viewer-friendly as it is when you open it in the Catalog view, but it does contain all of the same information.
      • When you hover over any of the fields in the tool dialog, a blue i appears. Hover over or click the blue i icon to view helpful tips specific to that field.

Contact ASF if you have questions about the Toolbox, or if you have suggestions for other tools to include.