SNAP Polarimetric Processing Sentinel-1

Description

A processing block that provides a SNAP polarimetric processing workflow that is applied on SAR scenes in the SAFE format.

See this block on the marketplace.

The SNAP block takes a Level 1C GRD image and generates a product ready for analysis by using a median filter for speckle filtering, creating a land-sea mask, and converting the image to the GeoTIFF format.

For each chosen polarization, a separate band will be generated in the output file. For instance, if both VV and VH polarizations are selected, the output will be a single GeoTIFF with two bands, one for VV and one for VH polarization.

Parameter	Overview
`bbox`	array of integers / required if Required if `intersects` or `contains` aren't specified. A bounding box to use as an AOI. Will clip to scenes that intersect with this box.
`contains`	object / required if Required if `bbox` or `intersects` aren't specified. A GeoJSON geometry to use as an AOI. Will clip to scenes that fully cover this geometry.
`intersects`	object / required if Required if `bbox` or `contains` aren't specified. A GeoJSON geometry to use as an AOI. Will clip to scenes that intersect with this geometry.
`polarisations`	array of strings / required Requested polarizations, vertical (V) or horizontal (H). The allowed values: `["VV","VH"]` `["HH","HV"]` `["VV"]` `["VH"]` `["HV"]` `["HH"]` The default value is `["VV"]`. If the requested polarization is not available in the input image to SNAP, the operation will fail and give a corresponding error message.
`mask`	string / required A type of surface to apply the mask to. The allowed values: `land` `sea`
`tcorrection`	boolean / required Whether to apply Range Doppler Terrain Correction based on a suitable Digital Elevation Model (DEM). The default value is `true`.
`clip_to_aoi`	boolean / required Whether the specified AOI should be clipped before processing: `true` — The AOI should be clipped first. `false` — The full scene should be processed. The default value is `false`.
`calibration_band`	array of strings / required Applies calibration to provide imagery in which the pixel values can be directly related to the radar backscatter of the scene. The allowed values: `beta` `gamma` `sigma` The default value is `sigma`.
`speckle_filter`	boolean / required Whether to apply Lee Sigma filter to remove speckle noise from the image. The default value is `true`.
`linear_to_db`	boolean / required Whether to convert the pixel intensity to normalized radar cross-section measured in decibel units. The default value is `true`.

Example

An example using the Sentinel-1 L1 GRD (SAFE) as a data source which is processed via SNAP after clipping it to the given AOI.

{
  "sobloo-s1-grd-fullscene:1": {
    "bbox": [13.358345031738283, 52.480689337378706, 13.395252227783203, 52.507654123207665],
    "ids": null,
    "time": "2018-01-01T00:00:00+00:00/2019-12-31T23:59:59+00:00",
    "limit": 1,
    "time_series": null,
    "orbit_direction": null,
    "acquisition_mode": null
  },
  "snap-polarimetric:1": {
    "bbox": [13.358345031738283, 52.480689337378706, 13.395252227783203, 52.507654123207665],
    "mask": null,
    "contains": null,
    "intersects": null,
    "clip_to_aoi": true,
    "tcorrection": true,
    "linear_to_db": true,
    "polarisations": ["VV"],
    "speckle_filter": true,
    "calibration_band": ["sigma"]
  }
}

Capabilities

Input

raster

up42_standard
`bands`	{ "or": [ [ "HH", "HV", "alpha" ], [ "VV", "VH", "alpha" ], [ "HH", "alpha" ], [ "VV", "alpha" ] ] }
`dtype`	`uint16`
`format`	`SAFE`
`sensor`	`Sentinel1GRD`
`resolution`	`10`
`processing_level`	`l1`

Output

raster

up42_standard
`bands`	`> (propagated)`
`dtype`	{ "or": [ "uint16", "float" ] }
`format`	`GTiff`
`sensor`	`> (propagated)`
`resolution`	`> (propagated)`
`processing_level`	`> (propagated)`

To know more please check the block capabilities specifications.

SNAP Polarimetric Processing Sentinel-1

Description

How it works

Example

Capabilities

Input

raster

Output

raster