Public sample — real engine run next to Wonderboom (FAWB). Flight paths use published runway thresholds. Demonstration PV footprint on open land beside the airport (AIP runways 11/29 and 06/24). ATCT cab location is indicative. Not a client deliverable or an assessment of any real project or obstacle application. Walkthrough video.
PQRS · Glint & Glare
Wonderboom Airport sample (FAWB)
Report no. PQRS-GG-SAMPLE-FAWB-002
Report date/time 2026-08-13 · 12:00 · Workspace 0.1.0 set to FAA 2021
Prepared for (client)
Public sample (demonstration)
Prepared by (contractor)
PQRS · PQRS Online
pqrs-online.com
Annual ocular glare assessment for the modelled PV array and receptors. Results are informational and do not constitute authority approval.
Origin -25.65861, 28.22430Origin ASL 1249.0 mDEM open-elevation (SRTM-class)Array area 341156 m²Panel tilt 20° / az 45°Eaves 2 m AGL
1. Executive findings
This assessment evaluates whether sunlight specularly reflected from the PV array can reach defined receptors (observation points, air traffic control tower cab, and/or approach paths), and classifies any predicted glare using established ocular hazard categories.
Green glare has low potential for after-image; yellow glare has potential for after-image before a typical blink response; red indicates higher retinal irradiance potential.
This workspace is set to FAA 2021. The ATCT card is the aviation PASS/FAIL (no glare of any kind at the cab). The flight path card reports approach glare hours for design context only — FAA 2021 does not apply the older 2013 yellow/red approach colour rule as a co-equal FAIL. A short historical note on FAA 2013 is in the appendix.
ATCT · FAA 2021
2021 policy guideline indicates “no glare of any kind” for ATCT
ATCT PASS
No glare predicted at the modelled ATCT cab.
Flight path · FAA 2021
Approach-path glare is reported for design context under this FAA 2021 workspace (not a 2021 PASS/FAIL test)
Flight path glare · 178.8 h
Predicted on modelled approaches: green 0.0 h · yellow 178.8 h · red 0.0 h. FAA 2021 does not use the older yellow/red approach colour rule as a PASS/FAIL; ATCT above is the aviation verdict.
2. Site and receptor maps
Basemap: Esri World Imagery (network required when opening the report). Overlays are this project’s modelled geometry.
Site footprint
Figure — Array footprint at site scale (satellite basemap · analysis overlays).
Airport / receptor context
Figure — Array with observation points, ATCT (if any), and flight-path geometry.
3. Method in brief
This assessment answers three practical questions: when reflected sunlight can reach a receptor through the year; where it can be observed (OP, ATCT cab, and/or approach path); and what ocular hazard category applies.
At each analysis time step the engine:
Sun position — solar elevation and azimuth for the site latitude/longitude and time.
Panel normal (n) — from fixed-mount tilt and azimuth (optics), independent of roof-pitch geometry used only for vertex heights.
Specular reflection (r) — incident sun direction reflected about n using r = 2(n·s)n − s.
Beam cone — sun angular size plus surface scatter; glare if the cone intersects the array footprint as seen from the receptor (within FOV where applicable).
Ocular classification — retinal irradiance Er and subtended source size ω place each event on the green / yellow / red hazard plot.
Figure — Specular reflection model used for this assessment, stamped with this site’s panel and height inputs.
4. Definitions supporting the findings
Green glare — low potential for after-image (flash blindness) before a typical blink response.
Yellow glare — potential for after-image before a typical blink response; historically screened on 2‑mile flight paths under FAA 2013 (informational in this report).
Red glare — potential for permanent eye damage under the classification framework; uncommon for typical PV specular glare with standard ocular parameters.
ASL / AGL / total elev. — ground height above mean sea level; height of the surface or eye above local ground; total = ASL + AGL used in 3‑D geometry.
Reflectivity (ρ) — fraction of incident irradiance treated as specularly reflected for ocular calculations (constant or incidence-dependent mode as recorded in parameters).
DNI — direct normal irradiance (W/m²); clear-sky / clear-day profile unless otherwise stated.
5. Footprint vertex heights
Each vertex carries ground elevation (m ASL) and height above ground (m AGL). Total elevation = ASL + AGL. Fetch ASL on the map before running for DEM-based ground heights. Roof pitch assigns per-vertex AGL from the eaves (low edge) toward the high-edge bearing.
Vertex
Lat (°)
Lon (°)
Ground ASL (m)
Height AGL (m)
Total elev. (m)
V1
-25.65947
28.22070
1249.0
2.00
1251.0
V2
-25.66299
28.22591
1249.0
2.00
1251.0
V3
-25.65824
28.22996
1249.0
2.00
1251.0
V4
-25.65714
28.23001
1249.0
2.00
1251.0
V5
-25.65661
28.22353
1249.0
2.00
1251.0
V6
-25.65949
28.22070
1249.0
2.00
1251.0
6. Receptor heights
OP / ATCT eye height is AGL; flight-path threshold crossing height is AGL at threshold. Ground ASL is from DEM when fetched.
Receptor
Type
Lat
Lon
ASL (m)
AGL (m)
Total (m)
FAWB-ATCT
ATCT
-25.65796
28.21528
1249.0
30.0
1279.0
FAWB-RWY11 threshold
flightPath
-25.65308
28.21279
1231.0
15.2
1246.2
FAWB-RWY29 threshold
flightPath
-25.65383
28.23098
1248.0
15.2
1263.2
FAWB-RWY06 threshold
flightPath
-25.66217
28.21624
1241.0
15.2
1256.2
FAWB-RWY24 threshold
flightPath
-25.65380
28.22484
1242.0
15.2
1257.2
7. Annual glare by receptor
The bar chart shows annual green and yellow glare hours stacked per receptor. Prefer these figures over a single site total when interpreting impact.
Receptor
Type
Glare
Yellow
Green
FAWB-ATCT
atct (ATCT)
0.0 h
0.0 h
0.0 h
FAWB-RWY06
flightPath
0.0 h
0.0 h
0.0 h
FAWB-RWY11
flightPath
0.0 h
0.0 h
0.0 h
FAWB-RWY24
flightPath
0.0 h
0.0 h
0.0 h
FAWB-RWY29
flightPath
178.8 h
178.8 h
0.0 h
Site total glare (sum across receptors): 178.8 h. Prefer per-receptor figures for interpretation.
8. Glare occurrence (day × time)
Each point is a predicted glare sample (green / yellow / red) by day of year (x) and time of day (y). Coarser time steps produce fewer samples.
FAWB-ATCT — no glare minutes predicted.
FAWB-RWY06 — no glare minutes predicted.
FAWB-RWY11 — no glare minutes predicted.
FAWB-RWY24 — no glare minutes predicted.
9. Analysis parameters
field
value
engineVersion
0.1.0
dayStart
1
dayEnd
365
minuteStep
10
minutesEvaluated
52560
elapsedMs
3427
peakDniWm2
1000
dniMode
variable
reflectanceMode
constant
coverType
smoothGlassNoAR
arrayTiltDeg
20
arrayAzimuthDeg
45
arrayAreaM2
341155.57480711
10. Assumptions & limitations
Clear-sky / clear-day DNI modelling; real cloud cover reduces occurrence.
Fixed-mount optics; each footprint treated as one contiguous planar array (module gaps / racking detail not fully resolved).
Ground ASL from Open-Elevation is approximate (SRTM-class); user AGL / roof pitch refine the array plane.
Hazard colours are decision aids; real ocular response is continuous.
Obstructions (buildings, trees, terrain masking) are not modelled unless explicitly enabled.
Times are standard time (add one hour where daylight saving applies, if relevant).
Results are PQRS-calculated using publicly published methodology references; they do not imply Sandia/SGHAT-licensed software outputs.
FAA does not endorse a specific analysis tool; sponsors remain responsible for Form 7460‑1 assertions where applicable.
11. Appendix — FAA 2013 flight-path note
Appendix — FAA 2013 (legacy / informational)
Under the superseded 2013 interim policy, sponsors also screened for no yellow or red glare on 2‑mile final approach paths. That colour test is not required under FAA 2021, which focuses on the ATCT cab. It is recorded here only so stakeholders who still ask for the older framing have a clear note — it should not be read as the primary aviation outcome of this assessment.
Flight-path colour screen: Yellow/red glare predicted on one or more modelled flight paths (about 178.8 h).
Predicted on modelled approaches: green 0.0 h · yellow 178.8 h · red 0.0 h. FAA 2021 does not use the older yellow/red approach colour rule as a PASS/FAIL; ATCT above is the aviation verdict.
PQRS