Aircraft Metrics Definition
Airspeed Metrics
Ground Speed vs True Airspeed: Ground speed (gs) represents the aircraft’s speed relative to the ground, while true airspeed (tas) accounts for air density and temperature conditions. True airspeed calculation requires outside air temperature (oat) and pressure altitude data not currently available in our model.
Indicated Airspeed (IAS): The airspeed reading from the aircraft’s pitot-static system (ias), which differs from true airspeed based on altitude and atmospheric conditions. This metric requires direct airspeed sensor data not present in our current ADS-B feed.
Climb/Descent Performance Metrics
Vertical Speed: Calculated using baro_rate (barometric rate) and geom_rate (geometric rate) to determine climb or descent performance. Positive values indicate climb, negative values indicate descent.
Climb Efficiency: Ratio of altitude gained to ground distance covered, calculated using altitude change (alt_baro or alt_geom) and position changes (lat, lon).
Flight Phase Detection Metrics
Takeoff Phase: Identified by rapid altitude gain (alt_baro increasing) combined with increasing ground speed (gs) and high climb rate (baro_rate > 500 ft/min).
Cruise Phase: Characterized by stable altitude (minimal baro_rate), consistent ground speed (gs), and straight track (track changes < 5°).
Approach Phase: Detected by decreasing altitude (baro_rate < -300 ft/min), decreasing ground speed, and altitude below typical cruise levels.
Landing Phase: Final approach with very low altitude (alt_baro < 1000 ft), decreasing speed, and stable track toward runway.
Signal Quality Metrics
Signal Strength: Direct measurement using rssi (Received Signal Strength Indicator) to assess reception quality.
Data Freshness: Calculated using seen (seconds since last message) and seen_pos (seconds since last position update) to determine data reliability.
Message Frequency: Messages per minute calculated from messages count and time window to assess tracking consistency.
Position Accuracy Metrics
Navigation Accuracy: Composite score using nic (Navigation Integrity Category), nac_p (Navigation Accuracy Category - Position), and nac_v (Navigation Accuracy Category - Velocity) to determine positional reliability.
Surveillance Accuracy: Assessment using sil (Surveillance Integrity Level) and sda (System Design Assurance) to evaluate overall tracking quality.
Flight Efficiency Metrics
Great Circle Deviation: Comparison of actual flight path (derived from sequential lat, lon coordinates) against the shortest great circle distance between origin and destination.
Altitude Optimization: Analysis of altitude profile against optimal flight levels for given aircraft type and distance.
Speed Consistency: Variance in ground speed (gs) throughout different flight phases to assess flight smoothness.
Fuel Efficiency: Calculated using fuel flow rate (fuel_flow) and ground speed to determine nautical miles per gallon. Requires engine performance data not available in our current dataset.
Environmental & Weather Metrics
Wind Speed & Direction: Calculated by comparing true airspeed (tas) with ground speed (gs) and track changes. Requires true airspeed data and wind vector information (wind_speed, wind_direction) not present in our model.
Turbulence Detection: Identified through rapid changes in altitude (alt_baro) and track (track) combined with accelerometer data (vertical_g_force, lateral_g_force) not available in ADS-B transmissions.
Weather Avoidance: Analysis of flight path deviations around weather systems using onboard weather radar data (weather_radar_returns) and precipitation intensity (precip_intensity) not included in our current data model.
Traffic Density & Separation Metrics
Aircraft Density: Count of aircraft within defined geographical boundaries using lat, lon coordinates and configurable radius.
Separation Metrics: Minimum distances between aircraft calculated using position data and altitude differences.
Airspace Utilization: Percentage of available airspace occupied by tracked aircraft at different altitude bands.
Operational Metrics
Emergency Detection: Identification of emergency situations using emergency codes, squawk codes (7500, 7600, 7700), and alert flags.
Autopilot Usage: Analysis of autopilot engagement using navigation modes (nav_modes) and flight path consistency.
Communication Quality: Assessment based on transponder performance, message consistency, and data completeness across all available fields.