Cell Statistics

Overview

The Cell Statistics tool performs cell-by-cell statistical calculations across a set of input rasters. Each output raster cell stores the statistic calculated from all input raster values at the same location.

Use Cases

Multi-temporal remote sensing analysis

• Calculate the mean or maximum value from multi-date NDVI imagery to analyze vegetation growth trends.
• Use standard deviation or range to measure vegetation cover variability.

Climate and environmental data integration

• Calculate mean or median values from multi-year temperature or precipitation rasters to build long-term climate surfaces.
• Use extreme-value statistics, such as maximum, minimum, and range, to analyze climate anomalies.

Land-use or classification result integration

• Use majority or minority statistics to combine classification results and create a voting-based classification raster.
• Use variety statistics to analyze land-use complexity.

Terrain analysis

• Compare multiple DEM versions or DEMs from different sampling methods to evaluate consistency and stability.
• Merge multi-source DEMs with mean or median statistics to reduce noise.

Risk and comprehensive assessment

• Combine multiple model outputs using mean or sum statistics for comprehensive assessment.
• Use standard deviation to identify uncertain areas where model outputs differ significantly.

Parameters

Parameter	Description	Notes
Select raster file or folder	Folder path containing the raster files to process.	The path must be valid and accessible.
Add raster file	Adds raster files to the input list.	Supports adding multiple files.
Statistical function	Statistic to calculate across the input rasters, such as sum or mean.	Choose a function that matches the analysis objective and data type.
Output path	Target directory for the result raster.	An absolute path is recommended. Make sure the directory exists and has write permission.
Output file name	Full output raster file name, including extension.	The extension determines the output format, such as .tif for GeoTIFF or .img for ERDAS IMG.

Steps

1. Start the tool.

   Open Spatial Analysis Tools, go to Local Analysis, and start Cell Statistics.

2. Select raster files or a folder.

   • Select raster file or folder: enter User Space/Toolbox/Base input data/Spatial analysis.

3. Add raster files.

   • Add raster file: click the add button on the right, add rasters from the folder to the raster list, and adjust their positions and order.

4. Select a statistical function.

   • Statistical function: select Sum.

5. Specify the output location.

   • Output path: User Space/Toolbox/Spatial Analysis Tools/Local Analysis.
   • Output file name: CellStatistics.tif.

6. Run the tool.

   • Click Run at the bottom of the pane and wait until the task list reports that the tool completed successfully.

Notes

Input alignment requirements

• Input rasters must have identical spatial reference, extent, and cell size. If they do not match, project, resample, or clip them first.

Result differences and interpretation

• Majority/minority: when multiple values tie for the highest or lowest frequency, the tool may select the first value encountered, which can introduce bias.
• Standard deviation and mean: if the input rasters are integer rasters, the output may be floating point. Check data type compatibility in later processing.

Performance and data volume

• More input rasters increase computation time.
• For large multi-temporal datasets, use block processing or parallel processing when available.

Choosing a suitable statistic

• Mean/median: suitable for continuous data, such as temperature and elevation.
• Majority/minority/variety: suitable for categorical data, such as land-cover or vegetation type.
• Maximum/minimum/range: suitable for extreme-value or stability analysis.
• Standard deviation: suitable for measuring variability or uncertainty.