Methodology

This page documents the scope, inclusion criteria, tier logic, and limitations of the Research Map. It is the companion to the master directory and the ecosystems page.

Scope

Included are non-commercial, research-active entities whose public material explicitly mentions at least one of:

• emissivity / emittance (spectral, total, normal, hemispherical, directional)
• reflectance
• transmittance
• absorptance / absorptivity
• thermal emission / thermal radiative properties
• infrared radiometry / radiation thermometry
• radiative cooling
• land-surface emissivity.

Included entity types: universities, national laboratories, research institutes, public research centers, and public agencies. Companies, vendors, and for-profit consultancies are excluded, regardless of their technical quality or visibility.

Inclusion criteria

An entity qualifies for the map if at least one of the following is true:

1. Named research unit or program explicitly on the scope topics (e.g. PTB WG 7.35 “Emissivity”, CAE “Advanced Thermal Management”, Christensen Research Group “Thermal Emission Spectroscopy Laboratory”).
2. Dedicated facility or named instrument (e.g. DISCO at PROMES-CNRS, BMEIR at IMT Mines Albi, System for Infrared Spectral Emittance of Materials at NIST).
3. Curated public database on the scope topics (e.g. JEDI at NASA JPL, TPDS at AIST / NMIJ, EKHI at Thermomat / UPV-EHU, USGS Spectral Library).
4. Sustained peer-reviewed output on the scope topics with evidence of ongoing activity (e.g. conference contributions, HAL/arXiv records, group publication pages).

Entities that appear in only one IR-EMPOWER talk and whose own institutional pages do not back up the emissivity framing are retained but flagged (see Tier IV).

Tier logic

Four tiers are used. The tier of an entity is set by the strongest available evidence — unit name, facility, database, or sustained output — and by the centrality of emissivity / radiative properties to the entity’s public identity.

Tier I — Core (12 entities)

Directly centered on emissivity / thermo-optical metrology. Typical profile: a unit or facility on the scope topics and a named instrument or measurement capability and sustained output. Examples: PTB (WG 7.35 “Emissivity”), CEMHTI-CNRS (simultaneous T + spectral emittance), PROMES-CNRS (DISCO), IMT Mines Albi (BMEIR), ISI Brno (cryogenic emissivity), Institute VINČA (direct pulse-heating), NIST (System for IR Spectral Emittance), AIST/NMIJ (TPDS), and the Thermomat/EKHI group at UPV-EHU.

Tier II — Extended (5 entities)

Essential once the scope broadens to reflectance, spectral libraries, and radiative-property data infrastructures. These entities may have emissivity as one of several roles rather than as their primary identity. Examples: NASA JPL (JEDI), ASU TES Laboratory, Brown RELAB, USGS Spectroscopy, LTeN-CNRS (architectured ceramics).

Tier III — Engineered emissivity / thermal photonics (5 entities)

Academic groups that design emissivity through nanophotonics, metasurfaces, and radiative-cooling schemes, plus closely aligned applied-energy groups. Examples: Stanford Fan Group, Columbia / Nanfang Yu Group, Utah / TIFT Lab, Vanderbilt / Caldwell Lab, LBNL Heat Island Group.

Tier IV — Emerging / flagged (4 entities)

Ultrahigh-temperature frontier, application-specific, or conference-affiliated where the emissivity infrastructure evidenced in the public record is hosted elsewhere. Examples: University of Virginia (~4000 °C work), Ruhr University Bochum / LEAT (combustion / powders), University of Wisconsin–Madison (IR emission via FTIR, less institutionally visible), LASP Boulder (participant affiliation only — talk content evidenced at PTB).

Ranking within a tier

Ranks within a tier are relative centrality indicators, based on:

• explicitness of emissivity in the public institutional identity;
• breadth of radiative properties covered (emittance, reflectance, transmittance, absorptance);
• specificity and uniqueness of the measurement capability envelope (temperature range, wavelength range, angular resolution, sample state);
• presence of a curated database or spectral library;
• evidence of ongoing activity (recent conferences, 2024–2026 output).

Two entities at the same rank are treated as comparable. Ranks are not absolute prestige rankings.

What is deliberately excluded

• Companies, vendors, and for-profit consultancies, even those with strong technical reputations (scope criterion).
• Individual researchers without a traceable institutional unit on the scope topics — a person’s participation in a conference is not itself sufficient evidence to rank their home institution high.
• Historical-only entities with no evidence of recent activity.
• Entities whose public pages do not mention any of the scope topics, regardless of reputation in adjacent areas.

Limitations and known gaps

• Several known specialist groups in Asia (beyond AIST / NMIJ) are under-represented relative to their likely activity. This is a visibility gap, not an absence-of-activity gap, and should be closed in future updates.
• Latin America, Africa, Oceania, and India are similarly under-represented in this version. Contributions naming specific research units on the scope topics are explicitly welcome.
• Smaller CNRS laboratories beyond the five listed may have emissivity work embedded inside broader thermal-science programs — future updates will systematically scan CNRS and HAL for additional nodes.
• Commercial-academic hybrid centers (e.g. certain applied-research institutes in the Fraunhofer, AIDIMME, or Tecnalia network) sit at the boundary of the scope criterion and are currently excluded pending explicit evidence of non-commercial research activity on the scope topics.

Evidence sources used

The primary public-facing evidence sources used in compiling this map were:

• Institutional laboratory pages (PTB, NIST, CEMHTI, PROMES, ICA, ISI Brno, NTC, VINČA, CNR-INO, CAE, LEAT, Thermomat, etc.).
• The IR-EMPOWER program (EHU-hosted workshop on infrared emissivity measurement) as a concentrated source of European speakers, institutional affiliations, and specific measurement-technique attributions.
• Database landing pages (JEDI, TPDS, EKHI, USGS Spectral Library, ASU TES Library, RELAB).
• Peer-reviewed articles, HAL records, and ORCID profiles where relevant.

Each institution page lists its own evidence sources at the foot.

A note on methodology

The map ranks research entities, not individual researchers. In several cases a speaker in the IR-EMPOWER program was highly relevant but the institutional website was not explicit enough to prove that the whole institution has emissivity as a core platform. Where that happened, the institution was kept on the map but placed in a lower tier. That is why PTB, CEMHTI-CNRS, PROMES-CNRS, ISI Brno, IMT Mines Albi / ICA, and CAE Würzburg rise to the top: they are not only publishing in the area; they visibly maintain experimental infrastructure or institutionalized research lines on emissivity and thermo-optical properties.

How to contribute

The machine-readable source of truth for this directory is _data/institutions.yml. Corrections, additions (new units, new instruments, new databases, new publications), and newly qualifying institutions are welcome. The recommended contribution format is a pull request that updates _data/institutions.yml and, for new entries, adds a matching institutions/<slug>.qmd page using an existing entry as a template.