NAME

KEYWORDS

SYNOPSIS

DESCRIPTION

i.hyper.import imports hyperspectral imagery into a 3D raster map (raster_3d).

The module reads supported hyperspectral products and converts their spectral bands into a single 3D raster map. The vertical (z) dimension of the 3D raster represents the spectral dimension, where each cell (voxel) contains the reflectance value for a specific spatial position (x, y) and spectral band index.

i.hyper.import is part of the i.hyper module family designed for hyperspectral data import, processing, and analysis in GRASS. It is typically used in combination with i.hyper.preproc, i.hyper.explore, i.hyper.composite, and i.hyper.export.

The module currently supports the following hyperspectral products:

• PRISMA – PRecursore IperSpettrale della Missione Applicativa (ASI)
• EnMAP – Environmental Mapping and Analysis Program (DLR / GFZ)
• Tanager – Planet Labs hyperspectral mission

During import, the appropriate product library from i_hyper_lib is automatically loaded (for example, enmap, prisma, or tanager). Metadata are parsed, bands are validated, and the resulting 3D raster map is created with band metadata (wavelength, FWHM, validity) and scene radiometric metadata (radiometric_quantity, radiometric_units).

The metadata are used by other i.hyper.* modules, so data imported with i.hyper.import or created with the same metadata structure are fully compatible across the toolset.

The resulting raster_3d map can be analysed with standard GRASS 3D raster tools (r3.mapcalc, r3.stats, r3.univar) or processed further with the i.hyper suite of modules.

NOTES

Imported 3D raster maps store hyperspectral reflectance or radiance values (depending on the product). Bands containing only NULL values are not added to the output raster_3d.

With the -n flag, source-band validity is recorded directly in bands.validity (with bands.count and bands.count_valid) without adding all-NULL bands to the output cube.

Imported datasets are written with metadata key derived=false. Datasets produced later by processing modules (for example i.hyper.preproc) are written as derived=true.

Extended metadata are written under unified branches (extended_metadata.acquisition, geometry, radiometry, atmosphere, quality, processing, uncertainty) and product-native provenance branches (extended_metadata.enmap, prisma, tanager). Unified and product-native keys may contain the same value when a unified key is derived directly from a source product key.

When the composites option is used, predefined or custom band combinations are exported as 2D raster composites (e.g., RGB, CIR, SWIR). All temporary rasters are automatically removed after import.

During import, i.hyper.import temporarily adjusts the computational region to match the input data, ensuring consistent alignment between imported bands. This region setting is temporary and restored at the end of processing.

i.hyper.import can also restore hyperspectral data directly from a native archive with product=ihyper. The archive structure is validated from its contents rather than the filename suffix, so any input filename is accepted as long as it contains a valid native archive. Such archives are unpacked into the current mapset and restore the native raster_3d together with its metadata.

Product notes:

• EnMAP L2 products are imported from the native single spectral image.
• EnMAP L1B products use two detector images (VNIR, SWIR). The importer first creates temporary north-up GeoTIFF files with gdalwarp, then runs the same band selection, composite, and r.to.rast3 steps as for L2.
• Because of the north-up preprocessing step, EnMAP L1B import usually takes substantially longer than EnMAP L2 import.
• Product levels that are not orthorectified are imported using product geolocation and nearest-neighbor assignment onto the current GRASS grid. This preserves original values, but may leave small holes or irregular borders where no source pixel maps to an output cell, which can be interpolated or otherwise handled later with existing GRASS tools.
• Tanager BASIC products (/HDFEOS/SWATHS/HYP/...) use per-pixel geolocation and Planet_Ortho_Framing for projection and gridding.
• Tanager ortho products (/HDFEOS/GRIDS/HYP/...) are imported directly in native map grid geometry (no geolocation reprojection).
• For Tanager ortho products, map grid parameters are read from /HDFEOS INFORMATION/StructMetadata.0 (UL/LR corners), /HDFEOS/GRIDS/HYP attribute epsg_code, and spectral dataset shape (rows/cols).

EXAMPLES

# EnMAP example
# Create a new GRASS project with EPSG:32633 (UTM Zone 33N)
grass -c EPSG:32633 -e ~/grassdata/hyper_33N

# Initialize and enter the new project (PERMANENT Mapset)
grass ~/grassdata/hyper_33N/PERMANENT

# PRISMA L2D example
i.hyper.import input=/data/PRISMA.he5 \
               product=prisma \
               output=prisma \
               composites='rgb,cir,swir_agriculture,swir_geology'

# Console output:
Importing product: PRISMA
Loading floating point  data with 4  bytes ...  (1254x1222x234)
Created 3D raster map with all bands: prisma (234 bands).
Generated composite raster: prisma_rgb
Generated composite raster: prisma_cir
Generated composite raster: prisma_swir_agriculture
Generated composite raster: prisma_swir_geology
(Fri Nov  5 13:12:00 2025) Command finished (1 min 23 sec)

Figure: PRISMA SWIR-geology composite generated with i.hyper.import
Data source: PRISMA Product © Italian Space Agency (ASI), used under ASI License to Use.

# Import an EnMAP L2A product and create RGB and CIR composites
i.hyper.import input=/data/EnMAP_data_folder/ \
               product=enmap \
               output=enmap \
               composites='cir,swir_agriculture' \
               composites_custom='650,1650,2200'

Figure: EnMAP SWIR-agriculture composite generated with i.hyper.import
Data source: Copyright © 2012-2025 EnMAP at Earth Observation Center EOC of DLR.

# Tanager BASIC radiance example
i.hyper.import input=/data/Tanager.h5 \
               product=tanager \
               output=tanager \
               composites='rgb'

Figure: Tanager-1 RGB composite generated with i.hyper.import
Data source: Planet Labs - Open Data, CC-BY-4.0.

# Restore a native hyperspectral archive into the current mapset
i.hyper.import input=/data/hyperspectral_data.ihyper \
                product=ihyper \
                output=ignored_name

For native archive restore, the archived map name is restored as-is and the output option is ignored.

SEE ALSO

DEPENDENCIES

• NumPy – Core numerical operations and array manipulation.
• h5py – Interface for reading and writing .h5 (HDF5) hyperspectral data products such as PRISMA and Tanager.
• pyproj – Coordinate reference system and geospatial transformation library.
• GDAL command line tools – gdalwarp is used for EnMAP L1B detector-image north-up preprocessing.

AUTHORS

SOURCE CODE

Available at: i.hyper.import source code (history)

Latest change: Wednesday Jun 17 14:05:16 2026 in commit: 2b69c1e5403d2a3377c287af027fcbad020a088c

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