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Google Gemma 4Gemma 4
CITIZEN SENSING • INNOVATION 03

Camera Radiometry.

Turn an ordinary sky photograph into a calibrated atmospheric observation.

All core measurements run in your browser. Your image stays on this device while Exur derives relative scene radiance, aerosol optical depth, and an AQI proxy.

FIELD INSTRUMENTSky observation console
DEMO OBSERVATIONS
01 / CAPTURE

Bring the sky into focus.

A
Current sky observation
Replace observationDrop a photo or browse your device
clear-sky-demo.svg4.80 MB · Demonstration observation

For a clean reading, point 45°–80° toward the zenith and away from direct sun.

02 / TELEMETRY

Camera signature.

Device / camera modelSony ILCE-7M4
Aperturef/5.6
ISO sensitivityISO 100
Shutter speed1/1000s (0.001s)
Capture date2025-05-15 12:00:00 UTC
Location signal28.6139°, 77.2090°
03 / ATMOSPHERE

Camera-derived estimate.

Moderate
Indicative AQI54Indicative proxy · Not reference-grade
PM2.5 mass proxy10.8 µg/m³AOD τ 0.050

Light aerosol or thin haze is present.

Health recommendationSensitive individuals should consider limiting prolonged exertion.
04 / PHYSICS

Radiometry result.

Beer–Lambert
Aerosol optical depth τ0.050Transmittance 206.3%
Relative luminance I51430.4Raw sky pixel 164.0 / 255
Luminance exceeds baseline I0.This sky is brighter than your clear-sky reference.
Lrel = (Y · N²) / (t · ISO)τ = −(1 / m) · ln(I / I0)I0 = 24933 (Solar elevation model) · θ = 18.9° · m = 3.07
05 / TRUST

Observation integrity.

AUTHENTIC · 100%
Observation confidence85%
High confidence

Image conditions are suitable for radiometric estimation.

✓
Scene framing / sky purity

Atmospheric sky observation verified with valid radiance characteristics.

✓
Exposure and tonal range

Exposure has a usable tonal range.

✓
Possible cloud contamination

Little evidence of cloud-like contamination in the analyzed sky region.

✓
Useful sky coverage

Sky coverage is adequate for the heuristic analysis.

✓
Possible humidity/haze interference

No strong visual humidity/haze risk was identified; humidity is not directly measured.

✓
Direct light or glare

No strong localized glare or brightness gradient was identified.

✓
Camera metadata

Camera metadata is present and within plausible ranges.

!
Radiometric operating range (-15)

Radiometric result may be outside the reliable operating range; the calculated value remains unchanged.

✓
Missing EXIF Telemetry

Camera exposure metadata (aperture, ISO, shutter) is present in EXIF.

✓
Camera hardware signature

Sony ILCE-7M4 identified.

✓
Exposure parameter plausibility

Aperture, ISO, and shutter values are physically plausible.

✓
Sky region framing

Adequate sky visible (~89% of frame).

✓
Daylight shutter speed

Daylight shutter speed is compatible with the radiometric model.

✓
Post-processing integrity

No known editing signature detected.

✓
Temporal consistency

Capture timestamp is plausible.

06 / CORROBORATION

Independent signals.

Gemma 4 vision

Upload a real image to compare visual haze with the physical estimate.

LOCAL REFERENCE
Preset demonstration reference
Anand Vihar, Delhi - DPCC · PM2.5 142.5 µg/m³Demonstration benchmark · Delhi Pollution Control Committee (DPCC) via OpenAQ
Reference comparison unavailable