Generate Masked SAR Raster (Image Analyst Tools)

Summary

Generates an output synthetic aperture radar (SAR) dataset that preserves radar measurements for the entire original input extent, while masking out a specified region of interest.

Usage

The output SAR data uses NoData pixels to mask out the specified region.
Ocean pixels are often used as the region to mask out.
Masking out the specified region of interest will help reduce noise, focus analysis on relevant regions, and improve subsequent analysis, such as classification, change detection, coherence estimation, interferogram generation, and phase unwrapping.
When the Input Mask Features parameter is not specified, the input digital elevation model (DEM) will be used to determine the land-water interface to generate the NoData mask for the ocean.

When the Input Mask Features parameter is specified, the input mask feature will be used to generate the NoData mask for the specified region of interest. In this case, a DEM raster is only required for nonorthorectified SAR data.

Both orthorectified and nonorthorectified SAR data are valid inputs.

Label	Explanation	Data type
Input Radar Data	The input radar data.	Raster Dataset; Raster Layer
Output Radar Data	The output radar data with a newly defined NoData mask.	Raster Dataset
Polarization Bands (Optional)	The polarization bands that will be processed. The first band is selected by default. Select all polarization bands if the output will be with the SAR Analysis tools.	String
Input Mask Features (Optional)	The input features that define where NoData pixels will be created.	Feature Layer
Mask Area (Optional)	Specifies whether pixels that are inside or outside the input mask feature will be used to generate the NoData mask. This parameter is only active when the Input Mask Features parameter is specified. Inside—Pixels that are inside the input mask area will be NoData pixels. This is default. Outside—Pixels that are outside the input mask area will be NoData pixels.	String
DEM Raster (Optional)	The input DEM raster. When the Input Mask Features parameter is not specified, this DEM will be used to generate the NoData mask for the ocean areas. When the Input Mask Features parameter is specified and the Input Radar Data parameter value is not orthorectified, this DEM is required to transform the feature's ground coordinates into radar coordinates.	Raster Layer; Mosaic Layer
Apply geoid correction (Optional)	Specifies whether the vertical reference system of the input DEM will be transformed to ellipsoidal height. Most elevation datasets are referenced to sea level orthometric height, so a correction is required in these cases to convert to ellipsoidal height. Checked—A geoid correction will be made to convert orthometric height to ellipsoidal height (based on EGM96 geoid). This is the default. Unchecked—No geoid correction will be made. Use this option only if the DEM is provided in ellipsoidal height.	Boolean

GenerateMaskedSARRaster(in_radar_data, out_radar_data, {polarization_bands}, {in_mask_features}, {mask_area}, {in_dem_raster}, {geoid})

Name	Explanation	Data type
in_radar_data	The input radar data.	Raster Dataset; Raster Layer
out_radar_data	The output radar data with a newly defined NoData mask.	Raster Dataset
polarization_bands [polarization_bands,...] (Optional)	The polarization bands that will be processed. The first band is selected by default. Select all polarization bands if the output will be with the SAR Analysis tools.	String
in_mask_features (Optional)	The input features that define where NoData pixels will be created.	Feature Layer
mask_area (Optional)	Specifies whether pixels that are inside or outside the input mask feature will be used to generate the NoData mask. This parameter is only valid when the `in_mask_features` parameter is specified. `INSIDE`—Pixels that are inside the input mask area will be NoData pixels. This is default. `OUTSIDE`—Pixels that are outside the input mask area will be NoData pixels.	String
in_dem_raster (Optional)	The input DEM raster. When the `in_mask_features` parameter is not specified, this DEM will be used to generate the NoData mask for the ocean areas. When the `in_mask_features` parameter is specified and the `in_radar_data` parameter value is not orthorectified, this DEM is required to transform the feature's ground coordinates into radar coordinates.	Raster Layer; Mosaic Layer
geoid (Optional)	Specifies whether the vertical reference system of the input DEM will be transformed to ellipsoidal height. Most elevation datasets are referenced to sea level orthometric height, so a correction is required in these cases to convert to ellipsoidal height. `GEOID`—A geoid correction will be made to convert orthometric height to ellipsoidal height (based on EGM96 geoid). This is the default. `NONE`—No geoid correction will be made. Use this option only if the DEM is provided in ellipsoidal height.	Boolean

Code sample

GenerateMaskedSARRaster example 1 (Python window)

This example will mask a region of interest using the input DEM to generate the NoData mask over areas of water.

import arcpy
arcpy.env.workspace = r"C:\Data\SAR"

out_radar = arcpy.ia. GenerateMaskedSARRaster (
     "S1B_IW_GRDH_1SDV_20181014T014104_20181014T014129_013142_018486_D82E.SAFE\manifest.safe",
     "VV", "dem.tif", "GEOID")
out_radar.save("IW_D82E_Mask.crf")

GenerateMaskedSARRaster example 2 (stand-alone script)

This example will mask a region of interest using a water feature class to generate the NoData mask.

# Import system modules
import arcpy
from arcpy.ia import *

# Set local variables
in_raster=r"C:/Data/SAR/SAR_RTC.crf"
polarization="VV"
in_mask_features=r"C:/Data/SAR/water.shp"
mask_area="INSIDE"
out_radar=r"C:/Data/SAR/IW_D82E_Mask.crf"

#Create output
out_Radar = arcpy.ia.GenerateMaskedSARRaster(in_raster, polarization,
    in_mask_features, mask_area)
out_Radar.save(out_radar)

Environments

Compression, Current Workspace, Parallel Processing Factor, Pyramid, Raster Statistics, Resampling Method, Scratch Workspace, Tile Size

Licensing information