Flight Data Providers

A detailed overview of the APIs used to fetch real-time aircraft positions and metadata for Celestial Transit Tracker.

Introduction

Celestial Transit Tracker relies on three primary flight-data APIs to deliver accurate, near real-time information: OpenSky, Aviationstack, and ADS-B Exchange. Each provider offers unique advantages in terms of coverage, latency, and data depth. Below, you’ll find a breakdown of what each API supplies, direct links to their documentation, and instructions on how to obtain any necessary API keys or accounts.

Note: Some services require registration or payment tiers for higher request volumes or extended historical data. We apologize for any inconvenience this may cause and wish such comprehensive flight data were freely available without restriction.

1. ✈️ OpenSky Network

❗ New OpenSky accounts created after March 2025 currently do not have API access. Please try using a legacy account or wait for OpenSky to re-enable access. Please contact OpenSky support to see if they can manually enable this for you. We’re sorry for any inconvenience.

OpenSky Network is a community-driven, non-profit platform that aggregates live ADS-B and Mode S data from receivers around the world. It offers free access (with optional registration) to:

Key Links:

OpenSky’s free tier imposes a rate limit of 100 requests per day for anonymous users. Registering an account increases that limit to 1,000 requests per day. Coverage can be spotty in regions without nearby receivers, and update frequency is generally 5–10 seconds per aircraft. Despite these limitations, OpenSky is ideal for hobbyist tracking and low-volume production use.

2. 🌐 Aviationstack

Aviationstack is a commercial flight-data provider that aggregates information from multiple sources, including ADS-B, airline schedules, and airport databases. It offers more consistent global coverage than most free APIs, at the cost of enforced rate limits and API-key requirements. Data fields include:

Key Links:

Aviationstack’s free tier allows up to 500 API requests per month, with a response time typically under 1 second. Paid plans start at 1,000 requests per day and include historical flights, airline routes, and airport schedules. Because Aviationstack combines multiple data feeds, it often yields higher reliability in remote areas compared to single-source ADS-B services.

3. 📡 ADS-B Exchange (via RapidAPI)

ADS-B Exchange is a community-driven repository of raw ADS-B messages. While its public website shows aggregated flight tracks, we access it programmatically through RapidAPI. This method provides:

Key Links:

Through RapidAPI, you can choose a tier that fits your usage: the free tier allows up to 500 calls per month with moderate latency, while paid tiers support thousands of calls per day with lower rate limits. Because ADS-B Exchange ingests raw messages from volunteers worldwide, it often provides the lowest latency (100–500 ms per update), but coverage depends entirely on volunteer-mounted receivers. If no nearby receiver exists, aircraft may not appear in the feed.

4. Why We Use Multiple Providers

No single data source can guarantee 100 % global coverage, minimal latency, and unrestricted access—all at once. By combining OpenSky’s freely contributed ADS-B data, Aviationstack’s aggregated airline schedules, and ADS-B Exchange’s raw feeds, we maximize:

We apologize for any inconvenience caused by registration requirements, API-key management, or pay-for-access tiers. We genuinely wish that such comprehensive, high-fidelity flight data were freely available to all developers without restrictions. Thank you for your understanding and continued support.