Aircraft ADS-B Data Integrity Check

Abstract

*† ‡ § ** Automatic Dependent Surveillance – Broadcast (ADS-B) promises to provide significant operational enhancements to military and civilian applications. However, as currently designed, ADS-B will not necessarily provide guaranteed, uninterrupted state and intent data from ADS-B equipped aircraft. Data dropouts, erroneous inputs, and deception may degrade data integrity. To assure ADS-B data integrity, a system has been built to provide continuous real-time state estimates of the aircraft being tracked and a verification that the aircraft is following the ADS-B broadcast intent. This system uses a suite of Kalman filters to smooth out noise within measured ADS-B signals, identify and suppress erroneous data, coast between data dropouts, and provide the current best state estimates. Continuous Geometric Conformance and Intent Conformance metrics are defined to analyze ADS-B intent verification. Geometric Conformance analyzes the aircraft states to verify that the aircraft lies within the horizontal and vertical Required Navigation Performance (RNP) limits. Intent Conformance compares the aircraft motion and the broadcast intent in horizontal, vertical, and speed dimensions. Examples demonstrate data integrity checks with simulated ADS-B data signals.