ICEYE GRD workflow

Available with Image Analyst license.

An ICEYE synthetic aperture radar (SAR) image must be processed before it can be used for visualization or analysis. Issues to address include calibrating to retrieve a meaningful backscatter value, mitigating speckle, removing radiometric and geometric terrain distortions, and rendering images with a large value range.

The Synthetic Aperture Radar toolset, in the Image Analyst toolbox, contains five tools you can use to generate calibrated, terrain-corrected, analysis-ready imagery data from ICEYE Ground Range Detected (GRD) data. The following tools are used to generate analysis-ready ICEYE GRD data, as shown in the table and diagram below:

ToolDescription

Apply Radiometric Calibration

Converts the input synthetic aperture radar (SAR) reflectivity into physical units of normalized backscatter by normalizing the reflectivity using a reference plane.

Apply Radiometric Terrain Flattening

Corrects the input synthetic aperture radar (SAR) data for radiometric distortions due to topography.

Despeckle

Corrects the input synthetic aperture radar (SAR) data for speckle, which is a result of coherent illumination that resembles a grainy or salt and pepper effect.

Apply Geometric Terrain Correction

Orthorectifies the input synthetic aperture radar (SAR) data using a range-Doppler backgeocoding algorithm.

Convert SAR Units

Converts the scaling of the input synthetic aperture radar (SAR) data between amplitude and intensity, between linear and decibels (dB), and between complex and intensity.

Workflow for processing analysis-ready imagery data from ICEYE GRD data

ICEYE GRD processing considerations

ICEYE auxiliary products provide a constant scaling factor to calibrate image values from digital numbers to sigma nought. Apply Radiometric Calibration uses the incidence angle coefficients, provided in the ICEYE auxiliary products, to calculate the incidence angle relative to the range. These incidence angles are used to convert sigma nought values to beta nought or gamma nought values.

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