GNSS guide

How to read a GNSS jamming and spoofing map

A GNSS map helps you explore where navigation observations change, when they change and which evidence supports an interpretation. SatellAItes brings reception indicators, satellite geometry and environmental context into one workspace. Start with the source and observation time: a coloured cell is a summary of available information, not an automatic diagnosis of a transmitter or a guarantee of reception.

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GPS jamming and spoofing map

Jamming, spoofing and what the map can establish

Jamming disrupts the reception of useful radio signals; spoofing attempts to make a receiver accept misleading signals or information. A map labelled “jamming and spoofing” still needs evidence to distinguish these mechanisms. Low reported navigation quality alone cannot confirm either one, identify the responsible actor or locate a transmitter.

Aircraft ADS-B observations can include Navigation Integrity Category (NIC) and Navigation Accuracy Category for Position (NACp). These describe different aspects of the reported navigation solution and must not be treated as interchangeable measurements of radio interference. Open a cell, read its source, sample information, observation interval and explanation, then compare nearby observations. A single unusual aircraft report deserves more caution than a consistent pattern supported by independent evidence.

Coverage, observation dates and UTC

An empty area does not demonstrate that GNSS reception is good. It may mean that no suitable observation reached the service, that coverage is sparse or that the selected period contains insufficient information. Similarly, a historical event is not necessarily still active. Always distinguish the time of an observation from the time the page was opened or a file downloaded.

Use UTC to compare reports across countries and midnight boundaries. Keep the start and end of the selected interval with every screenshot or export. Before comparing two dates, check that the sources and coverage are comparable; a change in the number of observations can alter the picture without proving a change in interference.

GPS, GLONASS, Galileo and BeiDou

GNSS is the collective name for global navigation satellite systems. GPS, GLONASS, Galileo and BeiDou are separate constellations providing positioning, navigation and timing signals. Their names are not synonyms for a single receiver, frequency or observation source. A receiver may use several constellations, while a public aircraft report may not identify which constellation contributed to its solution.

Use satellite layers to understand the geometric context at a location and time. An orbit or a satellite above the horizon does not demonstrate that a particular antenna received a usable signal. Buildings, terrain, local interference, receiver configuration and signal processing matter. Keep geometric availability separate from measured signal quality and from a confirmed interference event.

UTC, time and frequency, and synchronisation

GNSS supports timing as well as navigation. A timing receiver uses satellite signals and corrections to estimate a time reference; a disciplined oscillator can then support local synchronisation. Telecommunications, power networks and other systems may depend on this chain. Losing or corrupting a reference can matter even when no moving position is being displayed.

UTC, a constellation’s system time and a laboratory realisation such as UTC(k) are related but distinct concepts. Traceability and uncertainty depend on equipment, calibration and the complete transfer chain. The UTC dates shown by SatellAItes help align observations; they are not a calibrated time-transfer service, a frequency standard or a certificate of synchronisation accuracy.

UTC, TAI and time zones on the map and globe

A discreet clock shows the current UTC date and time in the top-right corner of the map and globe. Its NTP reference is obtained server-side from METAS; network delay is compensated and an estimated precision margin is displayed. Visible milliseconds do not guarantee metrological accuracy to one millisecond.

TAI appears below UTC with its current offset: TAI − UTC = +37 s. It is derived from synchronised UTC and the official offset. UTC and TAI use the same SI second; the 0.9 s limit concerns UT1−UTC, not TAI−UTC.

Open the time-reference group in the layer menu and enable Time Zone. Fine outlines show civil time zones, including oceans, with current local times and GMT±HH:mm offsets. Daylight saving rules and half-hour or quarter-hour offsets are included. Boundaries are simplified for display and remain approximate.

Hover over a zone for a temporary tooltip; click or tap to keep a panel open with its date, local time and GMT offset. Close it with ×, Escape or an outside click. UTC/TAI clock information is also available on hover, click and keyboard: Tab, then Enter or Space.

These clocks show the current time independently of the selected analysis period. When comparing observations, retain the analysis date and UTC interval. Without a valid UTC reference, no substitute local or TAI time is invented; time-zone outlines may remain visible.

A reproducible analysis with SatellAItes

Begin with a question, a place and a UTC interval. Open the map, select the relevant layers and inspect the available observations. Record source status and coverage before interpreting a colour or comparing locations. Use the satellite and environmental layers as context, rather than treating coincident weather or geometry as proof of a cause.

In the analysis workspace, compare the available records and retain the evidence behind your interpretation. When exporting a report, image or data, include the selected period, source attribution, filters and limitations. Separate what was observed from what remains a hypothesis. For a consequential operational decision, corroborate the result with appropriate receiver measurements and authoritative notices; this exploratory map is not a certified navigation service.

From reading to observation

GPS jamming and spoofing map

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