Fill Nodata / Gap Fill

Interpolate small nodata gaps from surrounding valid raster values.

Raster AnalysisEnd-User DocumentationTheory + Formula + Parameters

1. What This Feature Does

Interpolate small nodata gaps from surrounding valid raster values.

Cloud workflow: choose data → configure the scientific method → run → review the resulting layer/report. No programming is required.

2. Recommended Workflow

Choose bands. ↓ Set maximum search distance. ↓ Choose optional smoothing iterations. ↓ Fill gaps. ↓ Inspect whether interpolated areas are small enough to be scientifically defensible.

3. Theory, Methods & Equations

Neighborhood Gap Interpolation

Estimates missing cells from nearby valid values found within a search radius.

ẑ(p) ≈ weighted combination of nearby valid z(q)
Best used when: small holes or acquisition gaps need interpolation.

Post-Fill Smoothing

Optionally smooths the newly interpolated surface to reduce local artifacts.

Best used when: filled continuous data appear locally rough.

4. Input Data

InputTypeRequirementDescription
Input RasterrasterRequired

5. Parameters Available in the Application

ParameterDefaultChoices / RangeHow to Use It
Raster BandsLeave empty for All bands
Maximum Search Distance (pixels)1001 to —
Smoothing Iterations00 to 20

6. Output & Interpretation

The result should be interpreted according to the selected method and the physical meaning of the input data. Preserve source units, coordinate reference information, NoData meaning, acquisition date, and preprocessing level when comparing results.

Scientific interpretation: an algorithm can produce a numerically valid result even when the input data are unsuitable. Always check masks, units, sensor characteristics, spatial resolution and reference data.
Important: Do not use gap filling to invent large missing regions. Interpolated values are estimates, not observations.

7. Best Practices

  • Use analysis-ready inputs and remove invalid/cloud/noise artifacts that are not part of the target phenomenon.
  • Choose parameters from the physical scale of the data, not only from visual appearance.
  • Keep categorical and continuous rasters conceptually separate when selecting interpolation/resampling methods.
  • Compare the result with the source image and independent reference information.
  • Document the settings used when results will be compared across dates, sensors or study areas.