Not from reporting

Measured Events: What an Instrument or an Agency Recorded, Next to What Was Reported

Most events on the Watchfloor come from reporting. Some do not: they are made from a satellite measurement, published ship counts, a seismic record or an official forecast. Off-Nadir Delta keeps those as events of their own, with their own marks, and lets them say only what was recorded.

See them on the Watchfloor API reference

Quick answer — what a measured event is here

A measured event is an event made from instrument data or an official record instead of news reporting. Each kind has a mark and a category of its own on the Watchfloor map. Its title and summary are written by a fixed rule from the recorded values and are not rewritten by a language model. It is kept as its own event and is not merged into a reported event about the same place. It states what was recorded and never a cause. The kinds are: Thermal Anomalies, Transit Anomalies, Night-Light Anomalies, SO2 Anomalies, Earthquakes Near Facilities, Cyclone Wind Exposure.

What is a measured event?

A reported event starts from what media wrote: who did what, where. A measured event starts from a value: how hot, how many ships, how bright, how far from the epicentre. Nobody reported it; an instrument or an agency recorded it.

The two are different kinds of evidence, so they are kept apart. An event is a measured event only when everything in it is a measurement or an official record. Its category is set by rule, one category per kind, and its text is the text the rule wrote.

Not every kind is a measurement made by this product. Two of them take a record published by an agency (an earthquake, a forecast wind field) and state which registered places are near it or inside it. Each card below says which it is.

The kinds of measured event

Thermal Anomalies

satellite measurement, not a report

A heat source measured by satellite that is far above the recent level of the same spot: near a registered facility, or strong and isolated at night.

Heat sources: NASA FIRMS

About Thermal Anomalies →

Transit Anomalies

ship counts, not a report

The number of ships passing a strait or canal, or calling at a busy port, when it leaves that place’s own usual level. Built from published ship counts.

Sources: UN Global Platform; IMF PortWatch (portwatch.imf.org)

About Transit Anomalies →

Night-Light Anomalies

satellite measurement, not a report

A night on which the satellite-measured lights over a listed city were far below that city’s own usual level, judged only when most of the city could be observed.

Night lights: NASA Black Marble

About Night-Light Anomalies →

SO2 Anomalies

satellite measurement, not a report

Sulfur dioxide measured by satellite clearly above the local background around a volcano that has a current volcanic ash advisory.

SO2: Contains modified Copernicus Sentinel-5P data

About SO2 Anomalies →

Earthquakes Near Facilities

seismic record near a registered facility

Not a measurement by this product: a U.S. Geological Survey earthquake record, matched by distance to the registered facilities near its epicentre.

Earthquakes: U.S. Geological Survey

About Earthquakes Near Facilities →

Cyclone Wind Exposure

official forecast wind field over registered places

Not a measurement: the wind radii of an official forecast advisory for a tropical cyclone, laid over the registered facilities and straits inside them.

Cyclone advisories: NOAA National Hurricane Center

About Cyclone Wind Exposure →

What a measured event states

What was recorded, when, and where.
The level it is compared with, where the kind has one: the same spot, strait or city before.
Which registered places it was recorded at, is near or covers, with distances where they apply.
Where the data came from.

What it does not establish

A cause. The same reading is produced by very different things. Cause comes from reporting and imagery.
Damage or a closure. No kind says that a facility was damaged, closed or shut down.
An all-clear. A record that is not there does not mean nothing happened. Each kind has limits on what it can see, and its page lists them.
An official statement. Records built on an agency’s data are not that agency’s forecast, warning or assessment.

Measured events over the API

Measured events are events, so they come back from the events endpoint with their category. A page costs 3 tokens.

curl "https://offnadir-delta.com/api/v1/signals?categories=thermal_anomaly,transit_anomaly,nightlight_anomaly,so2_anomaly,quake_exposure,cyclone_exposure" \
  -H "Authorization: Bearer ond_..."

Each one carries measured: true and its measured_kind. The same query works through the MCP tool query_signals. Each kind also has a reader of its own, named on the page of that kind. Parameters and response fields are in the API reference.

What each plan sees

On every plan, the Watchfloor map shows that a measured event was recorded, when, and where. The marks are there without paying.

What was recorded in each one is part of the full account of the event, in the app, through the Delta Agent and over the API. Pricing shows which plan opens it.

Frequently Asked Questions

What is a measured event?▼

An event on Off-Nadir Delta that was made from instrument data or an official record instead of news reporting: a satellite measurement, published ship counts, a seismic record or an official forecast. It is shown with a mark and a category of its own, states what was recorded, and never states a cause.

How is a measured event different from a reported event?▼

A reported event is built from what media wrote. A measured event is built from a value an instrument or an agency recorded. The two are kept as separate events and shown as different kinds of evidence, so a measurement is never counted as one more report and a report is never presented as a measurement.

Does a measured event say what happened?▼

No. It says what was recorded: that a heat source was far above its usual level, that fewer ships passed a strait, that a city’s lights fell. It does not say why. The cause comes from reporting and imagery.

Are all of them satellite measurements?▼

No. Thermal, night-light and SO2 anomalies are satellite measurements. Transit anomalies are built from published ship counts. Earthquakes Near Facilities is a seismic record matched to registered facilities by distance, and Cyclone Wind Exposure is an official forecast wind field laid over registered places. The last two are not measurements made by this product.

Who writes the title and summary of a measured event?▼

A fixed rule, from the recorded values. The text is not rewritten by a language model, so nothing is added to what was recorded.

Is there an API?▼

Measured events are events: GET /api/v1/signals with categories set to one of thermal_anomaly, transit_anomaly, nightlight_anomaly, so2_anomaly, quake_exposure, cyclone_exposure returns them, each with measured: true and its measured_kind, at 3 tokens a page. Each kind also has a reader of its own; the page of each kind and the API reference name it.

What does each plan see?▼

Every plan sees that a measured event was recorded, when, and where on the map. What was recorded in each one is part of the full account of the event, which not every plan includes. The Pricing page shows which plan opens it.