Debuffering Timestamped ADS-B Records for Kinematic Applications

Because the Automated Dependent Surveillance – Broadcast (ADS-B) data format does not include explicit timing information, messages are typically time-stamped upon receipt, after they have passed through a number of buffering steps associated with demodulating and decoding the signal. These queues push apparent message arrival times later in time, and more importantly, affect the inter-arrival times between messages, which can then have downstream impacts when trying to use time-based kinematic data such as velocities and accelerations. This paper demonstrates how this buffering process manifests itself, and introduces a queueing based debuffering algorithm to ameliorate the situation. Two forms of validation are offered, one based on the numerical integration of rate-of-climb data to produce elevation, and one based on implicit timestamp differences derived from the native ADS-B data stream.