HOW IT WORKS
How FlightRouteMap Works
FlightRouteMap combines an ordered list of airports, their coordinates and spherical distance calculations into a route tool that can be checked independently. The map explains the geometry; the text and tables carry the distance results.
Airport Database
Airport records ship with the project as local JSON rather than a runtime backend database. The current dataset is imported from OurAirports with maintained Chinese names and aliases, and includes IATA, ICAO, bilingual names, cities, countries, coordinates, elevation and longest runway fields. The data page records the source date and its accuracy disclaimer.
Airport Coordinates
Each airport uses decimal latitude and longitude. The map, distance calculations, poster and airport detail panel share the same coordinates. The UI formats them with N/S/E/W and four decimal places so the map point and written result do not come from different records.
Great Circle Algorithm
Segment distances use a spherical distance function and the visual route uses sampled spherical interpolation. Total distance is the sum of adjacent segments; direct distance uses only the first and last airport. The displayed line is never measured back into a distance.
Map Projection and Route Rendering
The flat map unwraps antimeridian crossings into a continuous longitude copy and splits the path at the date line. The globe uses an orthographic view of the visible hemisphere. Both modes share airport coordinates and great-circle samples, but screen pixels are not distance units.
Why the result may differ from Google Flights
Google Flights can reflect a carrier, date, airway and actual flight selection, all of which change by itinerary. FlightRouteMap answers a different question: what is the geometric distance and route structure between the selected airport coordinates? It does not query live flights, fares, schedules or waypoints.
Why the result may differ from FlightRadar24
FlightRadar24 shows an observed or estimated track for a particular flight, including departure, arrival, holding, weather avoidance and airspace constraints. FlightRouteMap is a stable, repeatable Great Circle reference and does not represent any one flight track.
The full path from airport input to result
The user searches an airport record by code, name or city and places it in travel order. The app reads one shared coordinate record, calculates adjacent segments, calculates the first-to-last direct distance, and then renders the numbers, lines, labels and poster separately. Each stage can therefore be checked without a live backend.
How to verify a route yourself
Check the IATA, ICAO, city and coordinates in the airport detail panel, confirm the formula and units on the methodology page, and compare the segment table with the entered order. If the map and numbers appear to disagree, check the projection, antimeridian handling or current globe view before treating the geometry as a data error.
Data limits and updates
Airport names, codes, runway data and coordinates can change. Each import validates duplicate IATA codes, invalid coordinates and required fields, but source records can still lag or contain errors. Airport information and coordinates are for geographic display and distance calculation only, not navigation, flight planning or operational decisions.
Sources and further reading
- OurAirports public dataAirport CSV downloads, Public Domain statement and accuracy disclaimer.
- IATA Airport and Airline Code SearchIATA's official airport-code lookup.
- ICAO Location Indicators (Doc 7910)ICAO information about four-letter location indicators.