Sentinel-1 Bursts
Working with Sentinel-1 Burst products from the Alaska Satellite Facility
Sentinel-1 Burst Overview
A Sentinel-1 SLC contains multiple measurement TIFFs that contain the radar response data. Each measurement TIFF can be further broken down into a single radar pulse response message which is referred to as a burst.
There are multiple parameters that allow searching for bursts across sub-swaths and burst cycles. Depictions of a single burst, and the three available burst-related IDs are below.
Burst Metadata
CMR provides information on the burst collection, as well as the full metadata record for each burst.
Geographic Search
Visit ASF's Data Search - Vertex portal to get started. In this demo, we will look at bursts over Mt. Edgecumbe.
Start with a Geographic Search in Vertex to find Sentinel-1 Burst acquisitions of interest.
Click the Dataset drop-down and choose S1 Bursts.
Select an area on the map manually using the Area Of Interest map tools. You can choose to draw a point, line, square, polygon, or circle on the map, and edit or delete your drawing.
OR
Expand the Area of Interest window. Here, you can import a shapefile, GeoJSON, or KML file. Drag and drop a file, or click the Import File button to browse to a file location.
OR
You can Search for a location by name. Start typing the name of the location, and click to choose your desired location from the drop-down list.
For this exercise, we will draw a box around Mt. Edgecumbe.
Click Filters to expand the additional filters window. You can narrow your search by date range, Full Burst ID, and other parameters.
Once you are satisfied with your filters, click Search.
Click on a scene of interest in the scene (left) column. The footprint will be outlined in red on the map. Metadata for the scene is shown in the detail (center) column, including burst metadata. The associated file is shown in the file (right) column.
Click the Zoom icon at the top of the list to zoom to the extent of all the results in the list.
You can click the Baseline or SBAS buttons to view a stack using the selected scene as the reference. We will choose Baseline first.
Baseline Search
The baseline tool helps to identify scenes that are appropriate for Interferometric SAR (InSAR) processing. It provides visualization of perpendicular and temporal baseline data and allows you to easily change the reference scene used in each stack.
Vertex will direct you to the Baseline search, using the reference burst you selected.
The temporal and perpendicular baseline values are displayed in the scene (left) column, and scenes are plotted in the chart (right) column. You can sort the stack results by Meters or Days.
Clicking on a scene in the chart will navigate to that scene in the stack list.
You can click Baseline Criteria above the chart for additional filters.
In the Baseline Filters, you can adjust the ranges for temporal and perpendicular baseline with the sliders. You can also apply start and end date filters, or choose a seasonal range.
The chart and scene list will update according to the filters.
If you wish to set a different reference scene, you can select a scene from the list or chart, and click Baseline.
You can also launch an SBAS search using your chosen reference scene by clicking the SBAS button.
SBAS Search
SBAS is an acronym for short baseline subsets, which is a technique used in interferometry. The SBAS tool provides perpendicular and temporal baseline data, as well as scene pairs, for a chosen reference scene.
SBAS search lists the pairs with their temporal and perpendicular baseline values in the pair (left) column, and pairs are plotted in the chart (right) column.
Clicking on a pair in the chart will navigate to that pair in the stack list. Alternatively, clicking a pair in the list will highlight it on the chart.
You can click the Pairs icon to export the pair list as a CSV, which includes download URLs and temporal and perpendicular baselines.
Above the chart, you can use the Zoom icons to zoom in or out, or you can click Zoom to Fit to view all pairs.
You can adjust the temporal and baseline sliders.
You can also click SBAS Filters for additional filters.
In the SBAS Filters, you can choose an overlap threshold. You can also apply start and end date filters, or choose a seasonal range.
The chart and pair list will update according to the filters.
If there are gaps detected in your SBAS pairs, a warning message will be displayed.
If you wish to eliminate the gaps, you can modify your search filters. You could also add custom pairs for the missing connections. Click the Plus icon above the chart to start adding the custom pair.
Click a scene on the chart to start adding your custom pair. If you wish to stop adding the pair, you can click the Stop icon. To finish adding the pair, click another scene on the chart.
Custom pairs will be displayed with a dashed line on the chart. They will also be added to the pair list.
If you wish to remove a custom pair, select the dashed line from the chart, and click the Minus icon.
Downloading
You must be signed in to download data. Click the Sign in icon in the top right, and sign in using your Earthdata Login credentials.
Click the Add to Cart icon to add files to your Downloads Queue.
Click on the Downloads icon in the top right to open the queue.
You can use the icons next to a file to copy the file name, download the individual file, or remove it from your queue.
If you are using Google Chrome browser, you may download all files by clicking Data Download and selecting Download All. Progress indicators will appear next to each file as they download, and checkmarks will appear when the file is downloaded.
There are additional Data Download and Metadata Download options available.
Burst Extraction
Historically, accessing the individual bursts required downloading the entire archive hosting them. The Burst Extractor asynchronously extracts individual burst GeoTIFF and metadata XML products from a Sentinel-1 SLC.
Burst Extractor Overview
The following images showcase a single burst, half the bursts, and finally all bursts for IW3 over Southern California using the scene: S1A_IW_SLC__1SDV_20230525T015850_20230525T015918_048684_05DAF3_A621
More Info
Links to documentation, asf_search notebooks, and more are below.
Scan the QR Code to access this Storymap
