Methodology & Data Sources
This site tracks the daily military activity of the People's Liberation Army (PLA) around Taiwan. Every figure is transcribed verbatim from the daily public releases of the Republic of China (Taiwan) Ministry of National Defense (MND) — nothing is estimated or inferred. This page documents the source, update process, and the definitions of key terms such as the "Taiwan Strait median line" versus the "12 nautical-mile territorial sea", so journalists and researchers can verify and cite the data.
Data source
The single source is the ROC Ministry of National Defense "Real-time Military Activity" bulletins — the official daily announcements and flight-path graphics on PLA activity in the airspace and waters around Taiwan. This site only transcribes, structures and visualizes that data; it never incorporates information not confirmed by the MND.
Update frequency
Updated automatically once per day, fetched after the MND publishes around midday Taiwan time (≈ 12:00–14:00), with backup retry runs. If the MND is delayed or does not publish on a given day, that day is left blank rather than filled with an estimate. Historical records are append-only and never altered once written, so cited figures stay stable.
Key term definitions
An informal line down the centre of the Taiwan Strait, never recognized by any formal treaty between the two sides. For decades aircraft and vessels largely refrained from crossing it, so a crossing carries strong political and military signalling weight. However, crossing the median line does not constitute a violation of territory or sovereign airspace under international law and does not automatically trigger the right of self-defense. The "median-line crossings" figure on this site counts the PLA sorties that crossed this line on a given day.
Under the UN Convention on the Law of the Sea, the 12 nautical miles measured from the baseline constitute a state's territorial sea, and the airspace above it is sovereign airspace — the boundary that actually carries legal weight. Once PLA aircraft or vessels enter the territorial sea or airspace within this line, Taiwan may take defensive action under international law and its Defense Act. This is a different order of event from a median-line crossing.
A zone declared for the early identification of airborne objects; it is far larger than sovereign airspace. Entering an ADIZ is not a violation of sovereignty, but is commonly used to gauge the intensity and posture of activity.
"Sorties" is the number of PLA aircraft missions detected that day, per the MND's own count; "vessels" is the number of PLA Navy ships detected that day. Other activity such as surveillance balloons is noted separately in the notes column of the daily records.
How the data is compiled
The pipeline is deterministic and uses no manual estimation:
- MND bulletin → fields extracted into a single master CSV;
- Automated validation: median-line crossings may not exceed total sorties; the crossing rate must match the computed value (±1%); no duplicate dates; aircraft-type values must be valid;
- Only after validation passes are the static pages and charts generated, in both Chinese and English.
Citation & license
The underlying figures are public information from the MND. This site's compilation, field structure and charts are released under CC BY 4.0. Journalists and researchers are welcome to cite them, please credit:
Source: ROC Ministry of National Defense; compilation & charts: PLA Activity Tracker (https://pla-tracker.pages.dev).
- Raw data (CSV): https://pla-tracker.pages.dev/data/records.csv
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