cross-sensor-cal

Stage 01 Raster Processing

DO NOT EDIT OUTSIDE MARKERS

Purpose

• Convert NEON HDF5 scenes to ENVI rasters.
• Export ancillary layers for geometry and topography.
• Apply polygon and QA masks.
• Run topographic correction followed by BRDF adjustment.

Inputs and assumptions

• HDF5 reflectance products with NEON-style filenames.
• CRS defined in metadata (map info or coordinate system string); override if missing.
• Metadata keys used: Reflectance/Reflectance_Data, Ancillary_Imagery/*, Logs/Solar_*, to-sensor_*.

Outputs and guarantees

• Reflectance ENVI: NEON_<domain>_<site>_<product>_<tile>_<date>_<time>_reflectance_envi.img plus .hdr.
• Ancillary stack: *_ancillary_envi.img with bands Path Length, Sensor Azimuth, Sensor Zenith, Solar Azimuth, Solar Zenith, Slope, Aspect.
• Masked rasters append _masked.
• Topo+BRDF corrected raster: *_reflectance_brdfandtopo_corrected_<suffix>.img.
• Band names preserved from source metadata.

Configuration keys

• input_files: list of ENVI reflectance images.
• anc_files: mapping of ancillary band names to [path, index].
• corrections: ordered list, e.g., ["topo", "brdf"].
• export.output_dir and export.suffix: where corrected files land.
• num_cpus: Ray worker count.
• bad_bands, topo, brdf: sections controlling masking and coefficient options.

How to run

CLI

python src/neon_to_envi.py --images scene.h5 --output_dir out -anc
python src/topo_and_brdf_correction.py config.json

Python

from src.neon_to_envi import neon_to_envi
from src.mask_raster import mask_raster_with_polygons
from src.topo_and_brdf_correction import topo_and_brdf_correction

neon_to_envi(["scene.h5"], "out", anc=True)
mask_raster_with_polygons(envi_file, "polygons.geojson")
topo_and_brdf_correction("config.json")

Performance knobs

• num_cpus controls Ray parallelism.
• HyTools iterate(by="chunk") respects chunk_size to limit memory.

QA checks

• Confirm reflectance ranges (0–1); ancillary angles 0–180°.
• Plot per-band histograms to catch saturation or negative values.
• Verify masked pixels equal nodata values.

Troubleshooting

• Filenames must match NEON regex; use metadata_override when they do not.
• Inject missing metadata via metadata_override or raster_crs_override.
• ENVI header shape mismatches (samples, lines, bands) cause HyTools load errors—fix headers or regenerate files.

Last updated: 2025-08-18