ADS-B Exchange has free and paid API services to those who set up a feeder to collect data and commercial users, respectively. The revenue from paid API access is used to offset the costs of collecting and storing the data. ADSBexchange data collection requires that one can freely participate...
ADS-B Exchange can help you better understand and monitor aircraft movements, particularly in areas where traditional radar coverage may be limited. This can be especially valuable for tracking aircraft in remote or offshore areas, or for monitoring flights that are not covered by traditional radar...
https://adsbexchange.com/ - a large data archive, but no longer provides the full data publicly after the acquisition; https://flightaware.com/ https://flightradar24.com/ - a popular website, good coverage, but no public data access; https://opensky-network.org/ - supposed to be open...
the following restrictions: - no reselling the data; - no commercial use (except for within this application) without an agreement; - attribution is required) andADSB-Exchange(only provides samples of data from first day of each month: around 1.2 billion records per day with better coverage)....