SNAC - SNAP S-1 GRD Amplitude Change

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SNAC - SNAP S-1 GRD Amplitude Change

The S-1 Amplitude change on-demand processing service provides RGB composite of backscattering from a pair Sentinel-1 GRD IW and EW products (e.g. pre- and post-event) processed in SNAP.

EO sources supported:

  • Sentinel-1 IW and EW GRD products

Output specifications

The service provides 3 output products.

Output-1 – Amplitude Change RGB Composite
Correspondent file Amplitude Change RGB Composite
Information types RGB Composite : RED=(Slave Sigma0), GREEN=(Master Sigma0), BLUE=(Master Sigma0)
Raster format GeoTIFF
resolution Native or User selection
Projection types EPSG:3857 - WGS84 – Pseudo Mercator
Bit depth Unsigned Integer 8 bit
Processing Level RGB composite
Physical product available NO but a 8 bit GeoTIFF Product is provided
Browse product available YES as 8 bit PNG file
Output Filename example S1_GRD_VV_20200925_20201007_RGB_Amplitude_Change.tif

Output-2 - Master Product Backscatter
Correspondent file Master Product Backscatter
Information types SAR backscatter calibrated and terrain corrected [db]
Raster format GeoTIFF
resolution Native or User selection
Projection types EPSG:4326 - WGS84
Bit depth Float 32
Processing Level L2
Physical product available YES
Browse product available YES (GeoTIFF)
Output Filename example S1A_IW_GRDH_1SDV_20200925T191558_20200925T191623_034519_040465_DFBA_Orb_Cal_ML_TC_DB.tif

Output-3 – Slave Product Backscatter
Correspondent file Slave Product Backscatter
Information types SAR backscatter calibrated and terrain corrected [db]
Raster format GeoTIFF
resolution Native or User selection
Projection types EPSG:4326 - WGS84
Bit depth Float 32
Processing Level L2
Physical product available YES
Browse product available YES (GeoTIFF)
Output Filename example S1A_IW_GRDH_1SDV_20201007T191558_20201007T191623_034694_040A8A_43BF_Orb_Cal_ML_TC_DB.tif

Note

  • the “Browse GeoTIFF” product is always a GeoTIFF file with the same resolution of the physical product, with Uint8 bit depth and projection EPSG:3857.
  • The “Browse PNG” product is always a PNG file with the same resolution of the physical product, with Uint8 bit depth.

The S-1 Amplitude change on-demand processing service provides RGB composite of backscattering from a pair Sentinel-1 GRD IW and EW products (e.g. pre- and post-event) processed in SNAP. For the purpose of change detection, the user can create RGB band combination out of two amplitude bands of S-1 for instance pre-disaster and post-disaster. The user can manually (e.g. drag and drop, choosing from the list) specify EO data products. Additionally, the user can cut the output product to the specified bounding box. The output product can be used in further processing (outside of the platform) to extract for instance extent of flood.

Select the processing

  • Login to the platform (see user section)
  • Select the processing service SNAC – SNAP S-1 GRD Amplitude Change:
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Select Input Data

The service accept in input: Sentinel-1 IW and EW GRD products

In order to perform a catalogue search for the selection of the input product to be processed the user shall:

  • Click on the “EO data” button on the top right menu
  • Select the mission: Sentinel-1
  • Click on the lens icon on the left side menu to set additional query parameters
  • Select GRD as product type
  • Draw a rectangular bounding box over the map which correspond to the area of interest
  • Set the start and stop time on the bottom sliding bar in order to select the time interval
  • Perform the catalogue search and select the products of interest
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Processing Service Parameters

The “S-1 SNAP Amplitude Change” service panel is displayed with six parameter values to be filled-in:

  • Job title: a job caption to be assigned in order to recognize the job within the job list
  • Master product reference: selected master product from the catalogue search results basket
  • Slave product reference: selected slave product from the catalogue search results basket
  • Product Polarization product polarization to be considered in the processing
  • Subset Bounding Box (optional): Bounding Box to be used to crop the output product around the area of interest ; if left empty the full scene is considered and no crop is applied
  • Pixel Spacing in meter: output product pixel spacing in meter unit

Fill the parameters

After the selection of input data, the user can start filling the parameters:

  • Insert a job title (e.g. “Amplitude Change 2020-10-05”).
  • From the Feature basket table drag and drop the EO data product that you want to use as master.
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Running the job

Click on “Run Job” button from the processor configuration panel and wait for the job to complete.

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You can monitor the job status under “My jobs” tag which contains the list of other jobs associated to your user. If a failure occur you can re-submit the job. Details on the submitted job can be accessed by clicking on the title of the job.

View results

Once the job is completed successfully, click on the Show results on map button.

The service provides as output the following products in GeoTIFF format:

  • RGB combination : Red=( Sigma0 slave ), Green=( Sigma0 master ) , Blue=( Sigma0 master )
  • Sigma0 of master product [db]
  • Sigma0 of slave product [db]
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