MultiTracker
LESSARD
INDUSTRIES
2026
INDUSTRIES
2026
Space Station Data Upgrade — Crew rosters and docked-vehicle lists for both the ISS and Tiangong now come from The Space Devs Launch Library 2, replacing a hand-maintained GitHub source that was often weeks behind. Cargo Dragons now display by mission name (e.g. "Dragon CRS-2 SpX-34") with the capsule hardware as a subtitle, and Tiangong shows real crew (Shenzhou 21+) and docked spacecraft (Tianzhou, Shenzhou) instead of a static info card.
Flight Data Upgrade — Authenticated OpenSky contributor connection. Aircraft positions refresh more reliably, with higher rate limits and better resilience against anonymous-API throttling.
Under the Hood — API keys moved out of source, CORS locked to lessardindustries.com, cache busting tied to version, several small bugs cleaned up in the earthquake list, refresh loop, and tab switching.
Live aircraft positions are retrieved from the OpenSky Network, a non-profit association based in Switzerland that provides open access to real-world air traffic surveillance data collected by a worldwide network of ADS-B receivers. Data is used under their non-commercial research license and refreshes every 30 seconds.
Radar range is controlled by pinch-to-zoom (10–100nm). Range rings are drawn at fixed geographic distances and move inward or outward as you zoom, giving a physical sense of scale. Aircraft type icons are type-specific: helicopters appear as a top-down rotor cross, heavy widebodies are drawn slightly larger, and light GA aircraft slightly smaller than the default fixed-wing silhouette. Type data is looked up from hexdb.io by ICAO hex code and cached locally for 6 hours.
Flight route information (origin, destination, and airline) is sourced from adsbdb.com by callsign. Tap any aircraft to see the route displayed as city names with IATA codes. Routes are cached for 24 hours.
Squawk codes 7500 (hijack), 7600 (radio failure), and 7700 (emergency) are monitored in real time. If an aircraft in range is transmitting an emergency squawk, an orange alert badge appears next to its callsign in the list and in the detail panel.
Airport overlays are sourced from the OurAirports open dataset, which covers large and medium airports worldwide. The airport list is downloaded once and cached on the server for 7 days, then filtered to airports within your current radar range.
Citation: Matthias Schäfer, Martin Strohmeier, Vincent Lenders, Ivan Martinovic and Matthias Wilhelm. “Bringing Up OpenSky: A Large-scale ADS-B Sensor Network for Research.” In Proceedings of the 13th IEEE/ACM International Symposium on Information Processing in Sensor Networks (IPSN), pages 83–94, April 2014.
Visible and radio pass predictions and real-time position data for the International Space Station (ISS) and China's Tiangong space station are provided by the N2YO.com satellite tracking API. N2YO uses orbital elements from Space Track (AFSPC) to compute pass times, azimuth, elevation, and brightness for any observer location. The sky dome display shows where and when each station will cross overhead — solid arcs are naked-eye visible passes, dashed arcs are radio-only (above horizon but not sunlit). The ISS orbits at approximately 420 km altitude with a 51.6° inclination; Tiangong orbits at approximately 390 km with a 41.5° inclination, meaning it won't pass as far north or south as the ISS. Pass data refreshes every 30 minutes.
Current crew and docked spacecraft information for both the ISS and Tiangong is sourced from The Space Devs Launch Library 2. LL2 is a public REST API maintained by a community of space-flight enthusiasts that tracks active expeditions, docking events, astronaut rosters, and mission patches for every crewed space station. Crew lists, docking ports, and agency affiliations update as soon as launches and dockings are recorded.
Earthquake data comes from the United States Geological Survey (USGS) real-time earthquake feeds. The monitor displays magnitude 1.0+ events from the past month across the continental United States, plotted on a map centered on your GPS location. USGS data is public domain. Data refreshes every 5 minutes.
State border polygons are derived from Natural Earth 1:50m cultural data, covering all 48 continental states with full coastline and island detail. Great Lakes outlines use Natural Earth 1:10m lake polygon data. Map state is sourced from the PublicaMundi MappingAPI GeoJSON collection.
MultiTracker is a single-page web application built with vanilla HTML5, CSS, and JavaScript. All visualizations are drawn on an HTML canvas element. The app uses your device's GPS to center the display on your location. No data is collected or stored — everything runs in your browser.
Flight positions are calculated in real-time using bearing and distance from your location. Aircraft type icons are resolved asynchronously in the background after each data refresh, staggered to avoid overwhelming upstream APIs. Space station pass arcs use quadratic Bézier curves plotted on a sky dome projection where the center represents directly overhead (zenith) and the outer ring is the horizon. During an active pass, the station animates along its predicted arc in real time. The earthquake map uses an equirectangular projection with Natural Earth polygon data for state borders and Great Lakes, and supports pinch-to-zoom and drag-to-pan via the Pointer Events API.