--- id: data-sources/opensky-network about: label: OpenSky Network description: >- Swiss non-profit that collects aircraft position broadcasts through a volunteer network of receivers and offers them to researchers as a live API, a historical database and curated datasets. aliases: - OpenSky tags: - aircraft - flights - ADS-B - air traffic - airports - research data datasource: coverage: >- worldwide where its receivers hear aircraft, best in Europe and the US; nothing before 2013 resolution: >- per aircraft; state vectors at 5 seconds for signed-in users and 10 seconds for anonymous ones through the API cadence: >- live; flights with origin and destination derived nightly for the finished day access: >- REST API anonymous or with a free account and daily credits; full history through Trino for approved research institutions, aviation authorities and governments; curated datasets for download format: 'JSON from the REST API; SQL through Trino; datasets in CSV, Avro and JSON' homepage: 'https://opensky-network.org/' cost: >- free for non-profit research and education; licence required for commercial or operational use open: source: unknown data: partly api: 'yes' participation: open licence: >- non-profit research and non-profit education only; commercial use and operational use of the API need a written licence note: >- Anyone can feed the network by running a receiver. The full historical database is granted to research institutions, aviation authorities and government bodies, and to registered non-profits case by case. domains: - mobility provenance: origin: agent sources: - title: OpenSky (home page) url: 'https://opensky-network.org/' - title: About OpenSky Network url: 'https://opensky-network.org/about' - title: Frequently Asked Questions url: 'https://opensky-network.org/about/faq' - title: General Terms of Use & Data License Agreement url: 'https://opensky-network.org/about/terms-of-use' - title: 'OpenSky REST API, The OpenSky Network API 1.4.0 documentation' url: 'https://openskynetwork.github.io/opensky-api/rest.html' - title: Scientific Datasets url: 'https://opensky-network.org/data/scientific' - title: Social Impact url: 'https://opensky-network.org/about/social-impact' created: '2026-10-30' reviewed: '2026-10-30' reviewed_by: 'Claude, from the sources listed' status: draft --- The OpenSky Network is a non-profit association in Burgdorf, Switzerland, that collects air traffic data from receivers run by volunteers, companies, universities and government bodies, and archives the raw data in a historical database used mostly by researchers.[^2,4] It began in 2012 as a research project of armasuisse, the University of Kaiserslautern and the University of Oxford, and became an independent association in 2015.[^2] Most of the data comes from ADS-B (Automatic Dependent Surveillance-Broadcast): an aircraft works out its position and speed by GPS and broadcasts them on the 1090 MHz radio channel.[^2,3] The network also records Mode S messages on the same channel, and FLARM and ADS-C data.[^2,3] OpenSky keeps both the single transponder messages and tracks of the form "at time T, aircraft A was at position X and altitude Y", and works out each flight's origin and destination airports in a nightly batch from the finished day's tracks.[^3] It holds no schedules, delays, flight numbers or passenger counts, nothing from before 2013, and its coverage is best in Europe and the US.[^3] The REST API returns state vectors, an aircraft's position, altitudes, speed, heading and callsign at a moment, for the whole world or a bounding box, and flights by time, aircraft or airport for past days; a tracks endpoint is marked experimental.[^3,5] Anonymous callers get only the latest states at 10-second resolution; signed-in users, who authenticate with OAuth2 client credentials, get 5-second resolution.[^5] Calls cost credits, refilled daily and counted separately for states, flights and tracks.[^5] Anonymous use gets 400 a day, a standard user 4,000, and an active feeder whose receiver is up at least 30% of the month 8,000.[^5] The full dataset is reached through a Trino database interface, granted free to research institutions, aviation authorities and government organisations, and to registered non-profits case by case; private individuals are usually pointed to the curated datasets instead.[^3] One holds every Monday's state vectors from 2017 to 2022 at 10-second intervals, in CSV, Avro and JSON.[^6] Others are a COVID-19 flight dataset for 2019 to 2022, an aircraft metadata database in CSV, and a one-day snapshot of all the Trino tables as of 1 March 2026.[^6] The licence covers use "solely for the purpose of non-profit research and non-profit education".[^4] Any for-profit or commercial entity, including government and military contractors, needs a written licence, and so does "operational use of the REST API in any live product, service, or automated system", whatever the user's non-profit status.[^4] Publications, web pages included, must cite Schäfer, Strohmeier, Lenders, Martinovic and Wilhelm, "Bringing up OpenSky: A large-scale ADS-B sensor network for research" (ACM/IEEE International Conference on Information Processing in Sensor Networks, April 2014), and a copy of or link to the publication must go to OpenSky.[^4] Data may not be passed to anyone outside the user's own institution, and aircraft identifiers in non-anonymised data must be de-identified before publication.[^4] More than 800 academic papers have used OpenSky data.[^7] Journalists such as Bellingcat and the Financial Times, and institutions such as the IMF, the World Bank and the UN, have had access for non-profit work ranging from the effect of COVID-19 on air traffic to investigative reporting.[^7] For a model of a place, the state vectors over a bounding box show which aircraft pass over it and at what height, and the flight records count arrivals and departures at its airports.[^5]