GIS Tools

ASF ArcGIS Toolbox

The ASF_Tools ArcGIS Python Toolbox can be used with either ArcGIS Desktop or ArcGIS Pro, and contains tools that perform geoprocessing tasks useful for working with Synthetic Aperture Radar (SAR) data. The tools were designed to be used with Sentinel-1 Radiometric Terrain Corrected (RTC) SAR datasets, such as those available on-demand using ASF’s Data Search-Vertex portal, 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.

Toolbox Contents

Unzip Files Tool
This tool assists in file management when downloading .zip files from ASF. It 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 file paths that are so long that they are beyond the maximum allowed in default Windows unzip utilities.

Scale Conversion Tool
This tool converts 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/scales.

Reclassify RTC Tool
This tool generates a raster that includes only those pixels below a user-defined threshold value, and is designed for isolating water pixels. While intended for RTC files in dB scale, this tool could be used for any application where the user is interested in generating a spatial mask for values below a given threshold in a single-band raster.

Log Difference Tool
This 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. While intended for RTC files in amplitude scale, this tool could be used to compare the pixel values of any two single-band rasters, as long as there are no negative values (NoData values will be returned for pixels with a negative number in either of the datasets).

RGB Decomposition Tool
This tool generates an RGB image using the co- and cross-polarized datasets from an RTC product. Input datasets can be in either amplitude or power scale, and the primary polarization can be either vertical (VV/VH) or horizontal (HH/HV). Visit https://github.com/ASFHyP3/hyp3-lib/blob/develop/docs/rgb_decomposition.md for more information about interpreting RGB Decomposition images and the processing steps used to generate the color values.

Tutorials

After installing the Toolbox (see below), learn with ArcGIS StoryMaps how to use the different Tools. Visit the RTC On Demand! story map to learn how to order RTC products from ASF and work with the data using a variety of tools. Or, click on the buttons below to open the story maps for specific tools.

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, 2.5.x and 2.6.1, 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 (ArcMap)

  • 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.

Using 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 ArcGIS 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.
  • 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.

Accessing Help from within the Tool Dialog Box

ArcGIS Desktop

  • Click on the Show Help button at the bottom of the tool window to open the help panel.
    • This panel will display information about the tool in general if no field is activated.
    • If the user clicks on any of the parameter fields, information specific to that parameter will be displayed.
  • Click on the Tool Help button at the bottom of the Help pane to open another window that displays most of the information that would be displayed in the tool’s Item Description.

ArcGIS Pro

  • When you hover over any of the parameter fields in the tool dialog, a blue i appears. Hover over or click the blue i icon to view helpful tips specific to that parameter.
  • Hover over the blue question mark at the top of the geoprocessing pane to display information about the tool. Click on it to open the full tool description in a browser window.

Accessing Help from the Catalog Interface

ArcGIS Desktop

ArcCatalog displays the information contained in the xml metadata files in the Description tab for the toolbox and each tool.

In the ArcMap Catalog window, the Item Description for the toolbox or any of its constituent tools displays the xml content.

  • Right-click the toolbox or tool in the Catalog window and select Item Description to view the information.

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.

Current Release Information

ASF GIS Tools Release Notes

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

Custom Processing

ALOS PALSAR     If you are not able to find L1.1 (SLC) products for FBS, FBD, or PLR beam modes using Vertex or the ASF API, send a list of scene names to uso@asf.alaska.edu. We will process the data and provide you with options for downloading the finished products.

Sentinel-1     ASF HyP3 (pronounced “hype”) is a user service for processing Synthetic Aperture Radar (SAR) imagery that addresses many common issues for users of SAR data:

  • Most SAR data require at least some processing to remove distortions before they are analysis-ready
  • SAR processing requires a lot of computing resources
  • Software for SAR processing is complicated to use and can be prohibitively expensive
  • Producing analysis-ready SAR data is hard to learn

HyP3 On-Demand Radiometric Terrain Correction (RTC) and Interferometric SAR (InSAR) processing using GAMMA software are available through the ASF Vertex data search application. This allows you to use the powerful search tools of Vertex and then directly order data for processing without leaving the application. Processing is done in the cloud and results are available to download in less than an hour. 

Step-by-step instructions for using the Vertex On-Demand processing services are available in the RTC On Demand! and InSAR On Demand! user guides.

GAMMA RTC and InSAR processing are also available programmatically using the HyP3 API and HyP3 SDK. Detailed information about what these services provide and how to use them can be found in the ASF HyP3 User Guide.

Vertex Getting Started User Guide

Geographic Search Options

  • The Vertex map defaults to Satellite View
  • Navigate to your area of interest by dragging the map while holding down the left mouse button.
  • By default, the map-drawing tool is a bounding box. Click on the map once to specify the starting corner, move the mouse, then click again to finish the box. Additional drawing tool options are available in the toolbar at the top of the screen, including point, linestring, and polygon options.
    • Point allows you to define an area of interest by clicking on the map to place a point.
    • Line allows you to define an area of interest over a series of line segments by clicking on the map multiple times. Double-click to stop adding segments.
    • Polygon allows you to define an area of interest over an arbitrary polygon. You will receive an error message at the bottom of the window if there was a problem with the polygon (self-intersecting, reversed polygon winding order, etc.).
    • Box allows you to define an area of interest over a lat/long-aligned bounding box by clicking once to set one corner, and again to set the opposite corner.
    • Once a shape has been drawn, select the Edit current area of interest icon on the toolbar to move, add, and delete points. Select the Draw new area of interesticon to create a new AOI.
  • Dataset enables you to choose the dataset of interest.
    • If you need more information about a particular dataset, click on the appropriate icon in the Dataset selector.
  • Area of Interest gives you the option of importing an area of interest as a geospatial file or by entering a set of geographic coordinates.
    • Click on the down arrow next to Area of Interest in the top menu
    • Click the Import Area of Interest button in the Options window
    • Click Select Files and navigate to a folder on your computer, or drag and drop files into the box. GeoJSON, shapefiles, and KML files are supported provided they are in a latitude/longitude-based coordinate system, such as WGS84.
      • When importing a GeoJSON file, all geometries in the file will be included. If multiple geometries are found, a convex hull will be used to represent them in the search.
      • Shapefiles can be either a single .shp file, multiple shapefile components (.shp, .shx, .dbf), or a zip file containing one or more shapefile components. At a minimum, the .shp component must be included in all cases.
    • An area of interest may also be defined by a set of coordinates entered in the Options window.
      • Coordinates should be entered as decimal degrees in well-known text (WKT) format. Coordinates entered as a comma-separated long/lat string (e.g. -97.38,36.46,-53.44,36.46…) will be automatically converted by Vertex to WKT format.
    • You can save the coordinates of a search so they can be used to exactly recreate an area of interest in later searches.
      • Once the Area of Interest has been set, mouse over the coordinates. A Copy to clipboard icon will appear. Click on the icon and paste the coordinates into a new search or to a text file for later use.
      • Note: See the section Other Vertex Options for additional ways of saving searches.
    • At any time you can clear your search area by clicking on the Trash can icon in the top menu bar. 
  • Filters… enables you to further refine your search
    • Date Filters  Search dates are optional, so they default to empty.  If you are searching for specific dates, you can define the date range further in the Start Date and End Date fields. The date picker will automatically constrain your selection to a valid range for the selected dataset.
      • Note: this information may also be found by clicking on for a dataset.
      • Seasonal Search allows constraining the search to certain annual periods within an overall range of dates.  Click the Seasonal Search toggle and additional options will appear, allowing you to enter an overall date range (Start Date/End Date) and the seasonal range (Season Start Day/Season End Day).
    • Additional Filters allow for additional parameters to be applied to narrow your search and reduce the number of results. Not all filters will be available for all datasets.
      • File Type – Limit the search to specific types of files. Multiple selections allowed.
      • Beam Mode – Limit the search to specific beam modes. Multiple selections allowed.
      • Polarization – Limit the search to specific polarizations. Multiple selections allowed.
      • Direction – Limit the search to a specific orbit direction.
      • Subtype – Limit the search to a specific mission spacecraft.
    • Path and Frame Filters are available for select datasets. You may enter a single path or frame, or a range. Due to inconsistent Sentinel-1 framing, we recommend searching for a frame of interest by ±1-2 frames.
  • Once all parameters have been chosen, click SEARCH. Search results will appear in the footer area of the Vertex window, and on the map.
    • Note: The number of files that are predicted to match the current search parameters is displayed under the SEARCH button. If there are no predicted matches, the search button will be greyed out and display NO RESULTS.

List Search Options

  • Selecting List Search opens the List Search window and allows you to enter a list of scenes or file names.
    • Scene allows searching for specific scene names (granule names), and the results will include any files that are part of those scenes.
    • File allows searching for specific file names (product names), and the results will only include exactly those files.
  • Edit List – Opens the List Search window so you can make changes to your list
  • Once all parameters have been chosen, click SEARCH. Search results will appear in the footer area of your browser window, and on the map.
    • Note: The number of files that are predicted to match the current search parameters is displayed under the SEARCH button. If there are no predicted matches, the search button will be greyed out and display NO RESULTS.

Baseline Search Options

  • Selecting Baseline Search provides a space to enter the name of a Master Scene, and will then search for all secondary scenes that match the coverage area of the Master.
    • Note: If there are no matching scenes, the RESULTS button will be greyed out and display NO RESULTS.
  • Once a Master Scene has been entered, click SEARCH. Search results will appear under the map. Clicking on the Zoom to results icon  at the top of the left results column will display the location of the stack of scenes on the map.
  • The graph displays the Temporal and Perpendicular (spatial) relationship of the secondary scenes to the Master.
  • Clicking on  above the graph will open the Baseline Search window. Using the sliders, the Temporal and Perpendicular extents can be adjusted to limit the number of secondary scenes displayed in the results.

Search Results

  • In Vertex, a scene is considered to be a package containing all files, or products, that are related to a specific location and time.
    • For example, the column on the left of the Results panel displays the scenes returned from a search. The column on the right displays the file contents of each scene.
  • The maximum number of files that a search will return is displayed under the SEARCH button.
    • This number can be adjusted by clicking on the down arrow.  
    • The total number of files that match the search parameters is also displayed.
  • The Scenes column (left).
    • Click on the cart icon next to a scene name to add all the scene’s files to the download queue. The cart changes appearance when this is done.
    • Click on the zoom icon next to a scene name to zoom-in to the scene’s location on the map.
  • To view more information about a scene, click on the scene in the left column and the Scene Detail and Files columns will populate.
    • The Scene Detail column (center) provides a more detailed description of the scene, including Start Date/Time, Beam Mode, Path, Frame, Flight Direction, Polarization, Absolute Orbit, and a browse image (if available). Not all scenes will have all the extra information.
      • The Baseline Tool button opens the ASF Baseline Tool, which is used for creating InSAR stacks.
      • The SBAS Tool button opens the ASF SBAS Tool, which is another method of creating InSAR stacks.
      • The Citation button opens a new window with citation guidance for published works using data, imagery, or tools accessed through ASF.
      • The More Like This button creates a search based on the selected scene’s path and frame.
    • The Files column (right) displays a list of files available for the currently selected scene. You may download files immediately or add them to your download queue by clicking on the appropriate icon.
      • Clicking on the right arrow  in front a file (product) name will expand the file to show the ancillary files included. These files may be downloaded individually or added to the download queue.
        • Notes:
          1) You must be logged in to Vertex for this feature to work.
          2) This feature is not available for all datasets.

Downloads Queue

  • Clicking on the cart icon in the header, labeled Downloads, will display the contents of your current download queue.
    • Within the download queue, the list of files you have selected to download is displayed with some basic information on each file, such as file type and size.
      • File IDs (names) can be copied
      • Files can be individually downloaded
      • Items can be removed from the queue
    • Clear will clear all files from the queue. The option Restore will be displayed to allow you to undo this action.
    • Copy File IDs will copy the file names of all files in the queue for use elsewhere. For example, this list could then be pasted into the List Search window.
    • Data Download – Is used to download multiple products, with either the Download Python Script (.py) option or Metalink (metalink) file option.
    • Metadata Download – Is used to export the contents of the download queue to a CSV, KML, or GeoJSON file. The KML and GeoJSON files provided by this feature are compatible with the Geographic Search Import feature.

Other Vertex Options

  • Click on the three-bars menu icon next to the Sign in icon to display the menu options.
    • Copy Search Link will copy all the search parameters that have been set in the current search as a URL. The URL can then be pasted into a browser search bar to recreate the search exactly, or pasted into a document and saved to recreate the search later.
    • Share With Email will open a new email with the URL of the search to send to others.
    • Help & Tutorials provides both illustrated and video demonstrations on the basic steps for setting up a search and viewing the results.
    • What’s New provides updated information on new features and changes that have been added to Vertex for improved performance and functionality.
  • Click on the down arrow on the Search
    • Clear Search will clear all search parameters that have been set except for Search Type and Dataset.
    • Save Search* allows you to name and save all current search parameters in Saved Searches.
    • Saved Searches…* opens a list of searches that you have named and saved. Click on the  icon to load the search settings.
    • Search History…* opens a list of your 10 last searches that were not named and saved. Click on the  icon to load the search settings.
    • Help & Tutorials provides both illustrated and video demonstrations on the basic steps for setting up a search and viewing the results.
      • *Note: You must be logged in to Vertex for these options to be available.