PROProduction

Estimate interferometric coherence between SAR acquisitions (direct, complex, or bundle modes).

workflow pro

Workflow Narrative

SAR Interferogram and Coherence

Problem It Solves

Can this SAR pair be converted into defensible interferogram/coherence products with auditable provenance and QA diagnostics?

Who It Is For

InSAR practitioners and SAR operations teams requiring repeatable pair-level coherence/interferogram products.

Primary User

Infrastructure deformation monitoring teams, hazard intelligence groups, and SAR analytics operations.

What It Does

Produces interferogram, coherence, and valid-mask outputs from compatible SAR pairs in one dedicated workflow.
Accepts either direct SAR rasters, supported SAR bundles, or complex split real/imag SAR inputs.
Emits standardized machine-readable summary and optional HTML report artifacts for auditable downstream use.

How It Works

Resolves reference and moving SAR inputs from either direct raster mode, bundle mode, or complex component mode.
Optionally performs internal `sar_coregistration` handoff when grids are mismatched, unless the caller explicitly asserts a prealigned pair.
Computes either complex-domain interferometric phase and coherence magnitude (complex mode) or amplitude-domain proxy interferogram/coherence (scalar mode).
Uses summed-area coherence kernels and parallel row-chunk evaluation to reduce runtime on larger scenes; optional fast mode can further decimate coherence sampling.
Indicative formulas: $\phi = \mathrm{atan2}(\Im(z), \Re(z))$ for interferometric phase where $z = s_{ref}\,\overline{s_{mov}}$, and local-window coherence proxy from normalized cross-correlation magnitude.

Why It Wins

Unifies SAR pair ingest, optional alignment handoff, product generation, acceptance gating, and QA/report artifacts in one reproducible contract workflow.
Operational note:
When `auto_coregister_pair=true`, this tool invokes the existing `sar_coregistration` engine internally if the pair grids do not already match.
If the pair is known to already be aligned, prefer `assume_prealigned_pair=true` and leave `auto_coregister_pair=false` to avoid unnecessary alignment work.
Failed acceptance on the coreg residual gate indicates the pair/alignment should not be treated as registration-quality enough for trusted downstream interpretation.

Typical Buying Trigger

Teams need a dedicated production stage for interferogram/coherence outputs instead of ad hoc post-processing scripts.

Typical Presets

scalar raster pair: direct amplitude-domain processing with optional auto-coregistration.
bundle pair: bundle-native measurement resolution with identical output contract.
complex split mode: complex-domain phase/coherence computation from explicit real/imag rasters.
fast large-scene mode: reduced coherence workload via `performance_profile="fast"`, optional `coherence_decimation`, and selective artifact writing.

Inputs

Parameter	Optional	Description
reference_sar or reference_sar_bundle	no (unless complex mode)	Reference SAR source provided either as a direct raster path or supported SAR bundle root.
moving_sar or moving_sar_bundle	no (unless complex mode)	Moving SAR source provided either as a direct raster path or supported SAR bundle root.
reference_sar_real, reference_sar_imag, moving_sar_real, moving_sar_imag	no (complex mode)	Complex input mode components for explicit complex-domain interferogram/coherence processing.
reference_measurement_key, moving_measurement_key	yes	Optional bundle measurement selectors when SAR bundles include multiple measurement assets.
auto_coregister_pair, assume_prealigned_pair, coreg_mode	yes	Pair-alignment controls: either invoke internal `sar_coregistration` when needed or explicitly assert the pair is already aligned.
coreg_max_offset_px, coreg_decimation, coreg_min_overlap_fraction	yes	Optional scalar-mode coreg handoff tuning controls for search radius, sampling stride, and minimum overlap.
coherence_window, performance_profile, coherence_decimation	yes	Coherence kernel controls. Fast mode can reduce effective window size and decimate coherence sampling on very large scenes.
input_dem	yes	Optional DEM used for terrain-context masking and geometry-support pathways.
write_interferogram, write_coherence, write_valid_mask, write_html_report	yes	Optional artifact suppression controls used to reduce heavy-run output cost.
output_layout, output_compression, output_tile_size	yes	GeoTIFF write-profile controls for standard vs COG-style output and compression behavior.
output_prefix	yes	Output artifact prefix.

Outputs

Parameter	Type	Description
interferogram	optional GeoTIFF	Interferogram raster (complex phase in complex mode, amplitude-domain proxy in scalar mode) when writing is enabled.
coherence	optional GeoTIFF	Coherence magnitude raster from local-window pair statistics when writing is enabled.
valid_mask	optional GeoTIFF	Binary/flag mask indicating valid pair-support pixels used during computation when writing is enabled.
summary	JSON	Machine-readable summary report containing run metadata, QA diagnostics, timings, and artifact paths.
html_report	optional HTML	Human-readable customer-facing report generated from the summary contract for stakeholder review and QA traceability when writing is enabled.

Python Example

import whitebox_workflows as wbw

wbe = wbw.WbEnvironment(include_pro=True, tier="pro")

result = wbe.sar_interferogram_coherence(
    reference_sar="output/sar_coreg_reference.tif",
    moving_sar="output/sar_coreg_moving_aligned.tif",
    assume_prealigned_pair=True,
    coherence_window=7,
    performance_profile="balanced",
    output_prefix="output/sar_ifg_coh",
)

print(result)

License Notice

Use of this function requires a license for Whitebox Workflows Professional (WbW-Pro). Please visit www.whiteboxgeo.com to purchase a license.

Project Links

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