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NEON flightlines · drone imagery · bulk analysis

SpectralBridge

Connect reflectance processing, spectral libraries and sensor comparisons.

Airborne, drone and satellite observations differ in wavelength coverage, ground footprint, geometry and processing history. SpectralBridge is an open-source Python package for processing, harmonizing and comparing these observations, with explicit assumptions, provenance and QA.

Install from a source checkout with python -m pip install -e .; follow the setup instructions. API Reference · How to cite · AI transparency

SpectralBridge logo

Common framework. Sensor-specific treatment.

Why it exists

One landscape, different measurements.

NEON airborne instruments record reflected light across many narrow wavelength ranges. Drones such as those carrying MicaSense cameras provide fine local observations. Landsat satellites observe wider areas with larger ground footprints. SpectralBridge gives these systems a common framework while treating each according to how it was collected. Configured Landsat-like bands do not prove agreement with Landsat observations; aligning or aggregating ground footprints remains a separate scientific decision.

SpectralBridge applies configured corrections, constructs sensor-like wavelength bands from NEON observations, and compares completed products. Drone observations follow their own preparation path. The software preserves the meaning of each measurement and records the choices needed to review it.

Choose your way in

Choose the pipeline for your inputs.

Scientific products

From measurements to interpretable spectra.

The three workflows produce corrected observations, configured sensor-like representations and compact comparison evidence. Polygon extraction and spectral-library analysis are downstream products and modules, not additional processing pipelines.

Empirical polygon spectral library showing category variability, sampling hierarchy, spectral PCA and paired NEON to synthetic OLI representations
Real polygon spectra retain both within-group variability and overlapping ecological structure. The library's physical scale remains unresolved, so values are labeled in stored units. Explore the library, data model and source provenance.
Correction and QASpectral libraryBiological variationSensor translationIndependent comparisonExperimental mixture readiness

Follow optional downstream analyses without changing the core NEON, drone and bulk processing routes. Sensor information retention and one real-Landsat pilot supply different evidence; operational abundance validation remains incomplete.

Explore the technical figures

The system at a glance

Three technical views. Read them one at a time.

The original scientific figure is separated into enlarged panels here. The plots, wavelength ranges, processing stages, and translation relationships remain unchanged; the surrounding text provides a readable path through them.

01 / Observing systems

Measure at three scales.

NEON airborne imaging spectroscopy, MicaSense UAS observations and Landsat each sample reflectance differently. The supplied conceptual artwork uses NBAR terminology; the independent pilot documented here uses Collection 2 Level-2 surface reflectance and does not establish NBAR agreement. The first panel keeps their spectral ranges and sampling patterns visible together.

Why cross-sensor calibration matters →
02 / Processing chain

Correct before you compare.

The supplied processing diagram is a conceptual view. In the current package, NEON hyperspectral products use spectral convolution, while drone products use optional post-correction affine translation. Bulk analysis estimates and reviews the relationships from completed products.

Walk through the full pipeline →
SpectralBridge processing and calibration pipeline The supplied technical panel showing input reflectance, topographic correction, BRDF correction, spectral convolution with sensor response functions, and empirical calibration.
The source figure is a conceptual research diagram. Its calibration labels do not certify independent sensor agreement; current drone and NEON processing routes differ.
03 / Translation network

Use NEON as the hyperspectral anchor.

Matched MicaSense and Landsat products generated from the same corrected NEON source support diagnostic regressions. Actual Landsat comparison is a separate, optional validation step; a strong synthetic fit alone does not prove sensor interchangeability.

Inspect sensor harmonization →
  • DeterministicFixed inputs and configuration
  • RestartableReuse validated products
  • VersionedRecord software and parameters
  • Provenance trackedInputs, models, and outputs
  • Open evidenceInspect sources and gaps

The NEON processing path

Source observations in. Traceable products out.

The five steps below describe the individual-flightline NEON workflow. Drone and bulk follow their own linked vignettes above.

01Acquire
02Correct
03Harmonize
04Tabulate
05Review QA

Evidence, not mystery

Every transformation should leave a trail.

Validation campaigns record input variation, expected behavior, observed diagnostics, runtime, provenance, and failures. QA panels turn those records into something scientists can inspect.

Distinguish tests, QA and independent validation →

Already halfway there?

Carry on from the files you have.

Individual-flightline processing validates existing artifacts and resumes at the first missing or invalid stage.

Carry On My Wayward Son →

Ready when you are

Translate reflectance across sensors and scales.

What have we learned?

Difference → identity → quantity. All 10 researcher-category pairs differ in the observed matched cohorts. Full-NEON recognition falls from 85.2% for unseen polygons to 73.8% for held sites. The original synthetic Ridge120 advantage disappears under the matched15 NEON library control: retained diversity matters. Better prediction does not imply unique composition. Read the scientific synthesis for the evidence, reusable methods, mathematical explanation and remaining field-validation gap.