# TROPOMI NO₂ economic activity

> Atmospheric NO₂ measures how hard factories and traffic are running.

## OBSERVATION
(no observation yet) — observed at n/a.

## DELTA VS BASELINE
n/a vs (Same-week 3-year mean (cloud-filtered)).

## METHODOLOGY
- Source: ESA Sentinel-5P TROPOMI via Sentinel Hub Statistical API
- Cadence: Weekly
- Sensors / APIs: Sentinel Hub Statistical API, TROPOMI NO₂ L2 product
- AOI: 20 industrial AOIs (Wuhan, Shanghai, Detroit, LA, Houston, Antwerp, Mumbai, etc.) — pre-defined GeoJSON polygons
- Baseline method: Same-week 3-year mean (cloud-filtered)

## UNCERTAINTY
Cloud cover gates the signal — clouded weeks publish "no signal" rather than fake reads (Cloud cover gates the signal — clouded weeks publish "no signal" rather than fake reads)

## PROVENANCE
- Source URL: https://sentinel.esa.int/web/sentinel/missions/sentinel-5p
- License: Modified Copernicus Licence


## TRANSLATION (Casual EN)
The *TROPOMI* satellite — ESA's Sentinel-5P — measures *NO₂*, a gas emitted by engines and power plants. More NO₂ over an industrial region = more economic activity. It's the signal that flagged Wuhan's slowdown two weeks before official data in January 2020.

## DISCLAIMER
Vectorial Signals is descriptive market intelligence. Not investment advice. Past correlations don't predict future performance.