Fill NoData by Linear Interpolation
Overview
Linear interpolation fills NoData cells by estimating values from nearby valid cells along a linear trend. It is suitable for repairing small gaps in continuous raster surfaces. Different interpolation methods vary in smoothness, local-extreme preservation, and edge behavior.
Use Cases
- Fill small NoData holes in continuous raster data.
- Prepare spatially continuous raster input for later zonal statistics, threshold extraction, or map production.
- Repair gaps before visualization or downstream analysis.
Parameters
| Parameter | Description | Notes |
|---|---|---|
| Input raster file | Raster file whose NoData cells need linear interpolation | Required |
| Output raster file | Output raster file after linear interpolation | Required |
Steps
- Start the tool: Open Geoprocessing Toolbox → Spatial Analysis Tools > Raster Synthesis > Fill NoData, then start the Fill NoData by Linear Interpolation tool pane.
- Prepare input: Select the Input raster file and confirm that the data is complete and readable.
- Set core parameters: Confirm that the NoData areas to be filled are appropriate for linear interpolation.
- Set output: Specify the Output raster file and confirm that the output path, format, and naming rules meet downstream requirements.
- Run and inspect the result: Click Run, then check whether filled cells, value range, and spatial position meet expectations.
Notes
- Linear interpolation is best for small or narrow NoData gaps with gradual value changes.
- Use a projected coordinate system for distance-sensitive interpolation when possible.
- Sparse valid cells, uneven distribution, or outliers can reduce the reliability of the filled surface.