SLC

20100616 20100916 20101101 20101217 20110201

• SAR Processing is done for reconstruction of the raw image data.

• In order to have the image of a regular grid arrangement (Single Look Complex

(SLC)).

• The process is performed on SAR Processing is reading SAR parameters, Radar Signal Processing, and Range

and Azimuth Compression.

MULTI-LOOKING AND COREGISTERATION

The Super Master is the reference image of the whole processing, and all the processed slant range pairs will be co-registered on

this reference geometry.

Azimuth looks = 4 Range looks = 1

Based on the value of the following parameters which is available in the _slc.sml header file

PixelSpacingAz , PixelSpacingRg , IncidenceAngle

In case of different pixel spacing in the input data stack (the PALSAR FBD-FBS stack), the software will tune

automatically the multi-looking for each analyzed pair, to obtain the same pixel dimension set by the user with the

multi-looking factor on the Super Master image.

INTERFEROGRAM GENERATION

20100916_20100616 20100916_20101101 20101101_20101217 20101217_20110201

INTERFEROGRAM FLATTENING

20100916_20100616 20100916_20101101 20101101_20101217 20101217_20110201

Remove topography with DEM (ASTER GDEM V2). This process is a way to separate the effects of deformation in the

interferogram image from the effects of topography.

ADAPTIVE FILTER AND COHERENCE GENERATION

The filtering of the flattened interferogram enables to generate an output product with reduced phase noise. The

Interferometric Coherence, which is an indicator of the phase quality, is also generated.

This filtering approach, which is an extension of the Goldstein method, significantly improves fringe visibility and

reduces noise introduced by temporal or baseline related decorrelation.

20100916_20100616

Coherence image Image filtering

20100916_20101101

Coherence image Image filtering

20101101_20101217

Coherence image Image filtering

20101217_20110201

Coherence image Image filtering

PHASE UNWRAPPING

Phase unwrapping use a region growing algorithm. A coherence threshold is used to avoid or minimize unwrapping

error. Typically low threshold values between 0.15 and 0.2 are suggested to limit interruptions like phase jumps

during the region growing process. In this case a value of 0.18 will be used for the threshold value.

20100916_20100616 20100916_20101101 20101101_20101217 20101217_20110201

REFINEMENT AND REFLATTENING

This step is crucial for a correct transformation of the unwrapped phase information into height (or displacement)

values. It allows both to refine the orbits (i.e. correcting possible inaccuracies) and to calculate the phase offset (i.e.

getting the absolute phase values), or remove possible phase ramps.

In this case we used a Ground Control Point file that we have previously generated. The points is located onto the

Super Master image.

Super master image and GCPs

20100916_20100616 20100916_20101101 20101101_20101217 20101217_20110201

ATMOSPHERIC CORRECTION AND PHASE TO DISPLACEMENT + GEOCODING

Displacement from -60mm (dark blue) to +8mm (red).

20100616 20100916

Before atmospheric correction After atmospheric correction

20100616 20101101

Before atmospheric correction After atmospheric correction

20100616 20101217

Before atmospheric correction After atmospheric correction

20100616 20110201

Before atmospheric correction After atmospheric correction