{"@context":"https://schema.org","@type":"TechArticle","id":"PR-LGT-001","slug":"light-mapping","canonical_url":"https://flavorotor.com/research/light-mapping","machine_readable_url":"https://flavorotor.com/research/data/chapters/light-mapping.json","markdown_url":"https://flavorotor.com/research/markdown/light-mapping","title":"Light-distribution mapping","description":"A polar and position-indexed method for measuring spectrum, PPFD, DLI and temporal exposure in the rotating geometry.","chapter":"Research methods","version":"1.1","updated":"2026-07-26","table_of_contents":[{"id":"grid","label":"Measurement grid"},{"id":"conditions","label":"Required conditions"},{"id":"uniformity","label":"Uniformity statistics"},{"id":"output","label":"Published output"},{"id":"spectral-scope","label":"Spectral scope"}],"html":"
In brief

A polar and position-indexed method for measuring spectrum, PPFD, DLI and temporal exposure in the rotating geometry.

Measurement grid

\n

Measure at every cultivation position or at a justified symmetric subset covering axial level, angular position and radial plant plane. Record the detector orientation and distance from the central source.

\n

Required conditions

\n
ConditionMeasurement
Rotor staticposition-by-position PPFD and spectrum
Rotor operatingtime-resolved exposure or rotation-integrated measurement
Empty systemoptical baseline
Representative canopyself-shading and reflection effect
Thermal steady statelight output and leaf-temperature stability
\n

Uniformity statistics

\n
L-2
CVPPFD = 100 · sPPFD / mean(PPFD)
Position-to-position coefficient of variation.
\n
L-3
Umin/mean = PPFDmin / mean(PPFD)
Minimum-to-mean uniformity ratio.
\n

Published output

\n

The calibration report contains the raw grid, polar heat map, spectrum, measurement uncertainty, detector model, light state, system geometry and DLI calculation. A single centre-point value is insufficient.

Spectral scope

The mapping protocol records the measured spectrum and includes far-red photons separately where present.

","text":"In brief A polar and position-indexed method for measuring spectrum, PPFD, DLI and temporal exposure in the rotating geometry. Measurement grid Measure at every cultivation position or at a justified symmetric subset covering axial level, angular position and radial plant plane. Record the detector orientation and distance from the central source. Required conditions Condition Measurement Rotor static position-by-position PPFD and spectrum Rotor operating time-resolved exposure or rotation-integrated measurement Empty system optical baseline Representative canopy self-shading and reflection effect Thermal steady state light output and leaf-temperature stability Uniformity statistics L-2 CV PPFD = 100 · s PPFD / mean(PPFD) Position-to-position coefficient of variation. L-3 U min/mean = PPFD min / mean(PPFD) Minimum-to-mean uniformity ratio. Published output The calibration report contains the raw grid, polar heat map, spectrum, measurement uncertainty, detector model, light state, system geometry and DLI calculation. A single centre-point value is insufficient. Spectral scope The mapping protocol records the measured spectrum and includes far-red photons separately where present. [R33]","source_ids":["R33"],"visuals":[],"sources":[{"id":"R33","authors":"Zhen, Shuyang; Bugbee, Bruce","year":2020,"title":"Far-red photons have equivalent efficiency to traditional photosynthetic photons: Implications for redefining photosynthetically active radiation","publication":"Plant, Cell & Environment, 43, 1259–1272","doi":"10.1111/pce.13730","source_type":"peer-reviewed research","relevance":"Supports measuring far-red as part of the photon environment and evaluating it in combination with shorter wavelengths.","verification":"Publisher metadata checked 2026-07-26","url":"https://doi.org/10.1111/pce.13730","verified_on":"2026-07-26","verification_status":"DOI METADATA CHECKED","verified_against":"Publisher, DOI landing page, PubMed or official repository where available"}]}