File formats

Overview¶

Spire soil moisture data are distributed in four formats to support a wide range of use cases, including scientific analysis, GIS workflows, visualization, and point-based monitoring.

The available formats are:

• NetCDF4 — Comprehensive gridded data with full metadata

• GeoTIFF — Visualization-ready raster products

• CSV — Point-based time series

• GeoJSON — Point features with associated attributes

NetCDF4¶

NetCDF4 files provide the most complete representation of the data and metadata and are recommended for scientific and operational applications.

Characteristics:

• Generated for the user-defined region of interest

• Gridded data with full spatial referencing

• Plate Carrée (equirectangular) projection

• Coordinate reference system: WGS84 (EPSG:4326)

• Contains all variables, quality indicators, and metadata

• Suitable for analysis with scientific tools (e.g., Python, MATLAB, R)

Grid spacing depends on the product:

Common encoding¶

All core soil moisture variables share a consistent encoding:

To convert: soil_moisture = raw_value × 0.005. Valid range: 0–254 (0.000–1.270 m³/m³).

Anomaly files differ: they use int16 with fill value -9999 and the same scale factor of 0.005.

For complete variable tables, see the individual product pages:

• D-MSSM variables

• D-ESSM variables

• D-HSSM variables

• Anomaly variables

GeoTIFF¶

GeoTIFF files provide raster representations suitable for GIS applications and visualization.

Characteristics:

• Gridded soil moisture data with georeferencing

• Includes an associated advisory flag layer

• Generated for the user-defined region of interest

• Same grid spacing as the corresponding NetCDF4 product

• Plate Carrée projection referenced to WGS84

• Color-encoded for visualization purposes

• No-data value: 255

• Compatible with common GIS software (e.g., QGIS, ArcGIS)

CSV¶

CSV files provide time series data for specific point locations.

Characteristics:

• One file per location

• Contains soil moisture values over a specified time period

• Includes ref_local_time as the time reference column

• Includes geometry column in Well-Known Text (WKT) format

• Tabular format for easy use in spreadsheets or analysis tools

• No spatial grid information (point-based only)

• Suitable for monitoring applications and statistical analysis

JSON¶

JSON is the default format for the /soil-moisture/point API endpoint. Responses follow a consistent structure with data, location, times, and values fields. See the API endpoints documentation for response schemas.

GeoJSON¶

GeoJSON files provide geospatial point features with associated attributes.

Characteristics:

• Open standard geospatial interchange format

• Represents individual geographic locations as point features

• Includes soil moisture values and associated quality flags

• Human-readable JSON structure

• Compatible with web mapping tools and GIS software

Choosing a format¶

Select the format best suited to your application:

• NetCDF4 — Scientific analysis, modeling, and full metadata access

• GeoTIFF — GIS workflows and visualization

• CSV — Time series analysis at specific locations

• JSON — Programmatic access via API

• GeoJSON — Web mapping and lightweight geospatial exchange

For information on how files are named and versioned, see the file naming page.