Spire’s Aviation Tracking Stream pushes Target updates immediately when available and processed from both Satellite and Terrestrial sources in a data stream. It was designed to support multiple use cases:
You want to open a persistent HTTP connection and receive target updates continuously, as soon as possible as they’re available to Spire. If data freshness is not essential, target updates can also be streamed with a 4-hour delay via Recent History streaming.
You want to connect periodically, for example once an hour or once every 15 minutes, to retrieve all data produced since the last time you connected using the last
position_tokenyou received and then cut the connection again before reconnecting later on.
You want to retrieve data up to 24 hours old data, by selecting the data in time buckets. In this case, you will want to use the batch mode of the Tracking Stream endpoint.
The ADS-B capable aircraft transponders emit several messages with different bits of information several times per second. Spire’s satellites collect these messages that are processed into a Target Update, which corresponds to an update for each ICAO address for each 5-second interval.