Weatherhill airport program · Published 14 October 2026 · Source-linked research, prepared with AI assistance. No airport trial results are reported.
RVR answers an aviation question
Runway visual range, or RVR, is a calibrated estimate of the horizontal distance a pilot should see along a runway. FAA guidance ties it to runway lights or the contrast of other targets. Instrumented runways can have observations associated with touchdown, midpoint and rollout areas.
For a proposed intervention, the implication is straightforward: a promising observation at one location does not establish conditions along an entire runway. The study must identify which location, time period and operational question the measurement represents, and where it has no coverage.
MOR describes atmospheric optical transmission
Meteorological optical range, or MOR, describes visibility through the atmosphere using a defined contrast convention. RVR assessment also considers background light and runway-light intensity. These quantities can be related, but they should not be casually substituted in a research report or marketing claim.
A FogLab experiment should report the quantity its instrument actually measures. If it measures transmission over a short path, the result belongs to that path and configuration. Any conversion needs its assumptions stated, and any aviation interpretation needs a separate justification.
Build a measurement chain you can inspect
The proposed measurement plan starts with instrument selection, calibration history, physical siting and a stable reference. It records sampling intervals, clock synchronization, missing data and the treatment of contaminated or invalid readings. Those details make comparison possible when conditions change quickly.
Measurements should also reveal the system's footprint. Several positions can help distinguish a localized effect from a broader change in ambient fog. A research team should look for unintended sensor effects, such as a cleaner optical window, before attributing an improved reading to useful atmospheric clearing.
A useful data record links each observation to its instrument, location, quality flag and treatment state, so another reviewer can reconstruct the comparison.
From an optical result to an operational case
Four separate questions belong in the evaluation: did atmospheric extinction change, did the effect cover a useful area, was it sustained under relevant conditions, and could it support an airport decision? Passing one test does not automatically pass the next.
Weatherhill's proposed reporting keeps these stages visible. A local optical result remains a local optical result until further evidence supports expansion. Forecasts of recovered movements or reduced delay should be treated as scenarios and tested against the airport's actual constraints, traffic patterns and approved operating procedures.
Use public data for the right purpose
FAA's public RVR website describes itself as a situational-awareness resource rather than an official source. That makes source identity, timestamp, completeness and intended use essential features of any research display. A polished interface should never blur the distinction between a research feed and operational authority.
A design-partner study would inventory available observations and establish a permitted route to the records needed for analysis. It would also document what remains unknown. Airport-specific low-visibility plans and authorized procedures remain the basis for operating decisions throughout the research process.
Questions from airport teams
Is RVR the same as ordinary weather-station visibility?
No. RVR is a runway-focused aviation quantity. A weather-station visibility observation, a local optical experiment and RVR can differ in method, location and interpretation.
Can an experimental MOR improvement lower landing minima?
No. An experimental measurement does not change approved operating minima or establish that aircraft operations are authorized.
What would Weatherhill report first?
The directly measured optical result, its spatial and temporal limits, uncertainty, test conditions and instrument method. Operational benefit would be evaluated separately.
Sources & further reading
- Order 6560.10D — Runway Visual Range ↗Federal Aviation Administration · RVR definitions, visibility-sensor siting and use for aviation operations.
- Visual Guidance Lighting Systems — Runway Visual Range ↗Federal Aviation Administration · The role of runway visual range in precision approaches and low-visibility operations.
- Meteorological optical range — LT31 technical documentation ↗Vaisala · Manufacturer documentation explaining the optical relationship underlying MOR.
- Understanding Runway Visual Range with Vaisala Expert Jarmo Pilli ↗Vaisala · Manufacturer explanation of MOR, background luminance and runway-light inputs to RVR.
- Runway Visual Range Website Help ↗Federal Aviation Administration · The public display is a situational-awareness resource, not an official operational source.
- AC 120-57C — Low Visibility Operations / Surface Movement Guidance and Control Systems ↗Federal Aviation Administration · Airport-specific planning for low-visibility surface movements; issued September 26, 2023.