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Vertex is the Alaska Satellite Facility’s data portal for remotely sensed imagery of the Earth.
You can view the first of three ASF Datapool videos here, or you can see all of our training videos on our YouTube Channel located at www.youtube.com/AlaskaSatellite.
Simply follow the three steps listed below, and you will be using the ASF Datapool in no time.
To begin a search, use your mouse to draw a two-point box over your area of interest. If you have a specific set of geographic coordinates identified, you can enter them in the text box of the geographic region tab. The only parameter necessary to perform a search is the geographic region.
Choose a start and end date to bound the returned data; by default, searches will return all data available over that area for the past two years. To search seasonally, click the seasonal search box and enter the months and years of interest. The ASF Datapool contains data first collected in 1991 and is continuously receiving data from active SAR missions.
The platform tab lists all of the SAR platforms with data in the ASF Datapool; the icon button on the right will provide more information about the platform and sensor. By default, all platforms are included in your search.
If you have a list of specific granules that you would like to research, paste those granule IDs in the granule list text box. Otherwise, just skip this tab.
Click the search button below the list of parameters to reveal data matching your search parameters in the ASF Datapool.
Vertex returns all data available in the ASF Datapool that corresponds to your entered search parameters. Up to 1000 granules appear per page in the list; page controls and total number of returns are in the top right of the search returns list.
Scroll through the returned granule list on the right, as the yellow box on the map identifies the precise location of the data you are touching with your cursor.
There are two ways to filter, or narrow, your search returns: 1) the pre-defined platform post-search filters on the left or 2) the text filter at the top of the search returns list. The post-search filters on the left allow you to select specific beam modes, flight directions, and paths and frames of the satellite SAR data returned in your initial search. Select the specific filter attributes you are interested in and click the apply button. Your search results list and the map will soon reflect the results of your post-search filter choices. You can return to your original results by clicking reset within the specific platform filter or resetting all filters.
The second way to narrow your search results is with this text Find bar. Simply type any basic SAR parameter into this box and your search results list will filter according to your keystrokes.
Delete the text in the box to return to your original search results list.
Product profile pages are available for all returned data; click anywhere within the cell, or on the grey icon, to examine the profile page for that piece of data. Product profiles contain right-click downloadable browse images of the data, as well as some basic metadata about the granule. Also available through the product profile pages are two download options.
Direct download links for the data and the option to add the data to your download queue for bulk download at a later time are available through the product profile pages. You can also add to your download queue directly from the results list by clicking on the blue icon that contains a plus sign and a drop down symbol. If you have already filtered your results, you may want to choose the "Add all by type" option at the top of the search returns list, which will add all data associated with the chosen processing level to your download queue.
The download queue provides information about your selected data, such as granule name and anticipated file size, with the option of removing any data you may have decided not to download after all. Download options here include a Google Earth KML, a csv file (includes direct links for downloading granules individually), and Metalink for bulk downloads. Both the KML and Metalink files will download to the user's system. Users then must use the applications to open the files. A download client is required to translate the Metalink bundled files into the individual zip files containing your data. A list of download clients and access links for those tested and recommended by ASF to receive Metalink bulk deliveries is also available through the download queue.
The unrestricted products UAVSAR and AIRSAR are available for direct download and bulk download without the creation of an account on Vertex.
Restricted data will not be available to add to your download queue until you log in to your Vertex (and have the appropriate permissions on your account based on your approved proposal) account. To login to Vertex, open the login modal at the top right of Vertex, and use your ASF DAAC user id and password. If you do not have an account on Vertex for accessing restricted data, please click the register button in the login modal for information on account creation. Once logged in, you can directly or bulk download all restricted data.
All processed SAR data delivered through Vertex is via zip file compression, with the use of zip64 for UAVSAR data products.
You can view our ASF Subsetter video here, or you can see all of our training videos on our YouTube Channel located at www.youtube.com/AlaskaSatellite.
Simply follow the three steps listed below and you will be using the ASF Subsetter in no time.
The ASF Subsetter offers numerous SAR mosaic datasets delimited as distinct seasonal datalayers. Using your mouse, choose a continent, then a unique datalayer for further examination. Select the note button next to a datalayer to access the Dataset Profile of accompanying information about that specific mosaic.
A mosaic Dataset Profile describes the sensor, acquisition conditions, and basic mosaic parameters. Each profile also contains a brief dataset abstract.
Shift, click and drag a bounding box over the area you are interested in cutting, or subsetting, out of the moasicked image.
This is the location to define the way you want your subset image of the mosaic to be delivered to you. Below are descriptions of the available download options.
A type of transformation that maps coordinates from the surface of a spheroid (i.e. Earth) to coordinates on a plane using mathematical algorithms
Vertex offers these image formats for immediate download: JPEG, GeoTIFF.
Interpolation is an algorithm-based imaging method to increase (or decrease) the number of pixels in a digital image. Vertex uses these interpolation methods: Nearest neighbor, Moving average, and Bilinear interpolation.
Denotes the number of distinct pixels displayed in the X and Y dimensions. Units (e.g., decimal degrees, meters) depend on the associated projection; default resolution is the native pixel resolution of the datalayer.
Values represent the geographic coordinates of the area selected from the image using the bounding box tool. Subsets can only be selected from one datalayer at a time, and are limited to a rectangular shape.