Traffic Information Service

SkeyDrones Traffic Information Service (TIS) detects both manned and unmanned aviation

Traffic Information is one of the four mandatory services U-Space Service Providers (USSPs) must provide to drone operators in U-space and is required to allow BVLOS operations to Detect and Avoid (DAA) possible mid-air collisions with either manned or unmanned aviation.

SkeyDrone has developed and operates a fully functional Traffic Information System (TIS). This service is available in different high-density areas like the Port of Antwerp, the Brussels CTR, and all along the Belgian coastline (where both the demand for drone operations as well as the aircraft encounter rate are high).

SkeyDrone’s TIS offers traffic information from both manned and unmanned aviation from several reliable sources. In areas where this multi-source traffic data does not guarantee reliable coverage, for example in very low-level (VLL) airspace, a network of meshed ground receivers is added. The information is then fused into one unique air picture offering the most complete and most reliable situational awareness available.

This Traffic Information is visualised and enhanced by the  SkeyDrone Monitor software


SkeyDrone Monitor features:

Intrusion detection alerting: an alert warns users of any intrusion in their area of interest,

    • identifying manned or unmanned (type of aircraft)
    • cooperative or non-cooperative (drones)

Conformance Monitoring alerting:

    • Drone operator: an alerts warns the user when it’s leaving its authorised flight volume. Alerts are equally triggered upon non-compliancy to time and state of the authorization (land now notification).
    • Geozone manager: an alert warns the user upon any non-conforming flight activity, by integrating approved flight authorizations

Loss of separation detection alerting: an alert warns the drone operator of any aircraft approaching their UAV, allowing the pilot to react by altering the intended flightpath or descending to a safe altitude.

This feature can be used as a TMPR detect (SORA). 

SkeyDrone Monitor displaying Traffic Information

SkeyDrone’s ‘aviation-grade’ Traffic Information Service (TIS)

SkeyDrone’s ‘Traffic Information Service’ is unique in the way that it applies altimeter corrections for pressure and temperature as specified in Icao Doc 8168 PANS Aircraft Operations Volume I (Flight Procedures) Chapter 4 ‘ALTIMETER CORRECTIONS’. By doing so, the “barometric altitude” received from the aircraft altimeter is transformed into the true altitude (above MSL) and height (above Ground).

Altitude to height Conversion

The SkeyDrone Traffic Information Service is using the Digital Elevation Model over Europe (EU-DEM) issued by the European Environment Agency (EEA) and has a geographic accuracy of 25 meters (horizontal grid) and a vertical accuracy of +/- 7 meters RMSE. For optimising performance, a lowered horizontal resolution of 100 meters was used. Noting that the slopes in Belgium are not that high, errors due to this approximation should be relatively negligible.

Altimeter pressure correction

The SkeyDrone Traffic Information Service corrects altitude for deviations in pressure where the pressure is lower or higher than the standard atmosphere (1013,25 hPa). Instead of using the linear approximation as specified in Icao Doc 8168 section 4.2.1 where a correction of 30ft per hPa should be applied, SkeyDrone is applying a more accurate correction based upon a parabolic approximation that results in a maximum error of 2,5ft at levels up to 2000 m (6000 ft)and in a pressure range between 950 hPa and 1050 hPa. Historical data on pressure showed that in Belgium the pressure variation is between 950 hPa and 1050 hPa since the start of these measurements in 1903.

Altimeter temperature correction

The SkeyDrone Traffic Information Service corrects the deviation between the actual temperature and the temperature of ISA (+15°C at 1013,25hPa) assuming a linear variation of temperature with height (ref Icao Doc 8168 section 4.3.3). This linear approximation assumes a constant off-standard temperature lapse rate. The actual lapse rate may vary considerably from the assumed standard, depending on latitude and time of year. However, the corrections derived from the linear approximation can be taken as a satisfactory estimate for general application at levels up to 4000 m (12000 ft). The correction from the accurate calculation is valid up to 11000 m (36000 ft) ((Icao Doc 8168 section 4.3.5)).

For both the altimeter pressure correction and the altimeter temperature correction, the SkeyDrone Traffic Information Service is using the METAR reports of 17 airports located in Belgium or close to the Belgian border. The corrections are based on the measured temperature and pressure provided in the METAR message for the nearest airport.

Note that the SkeyDrone Traffic Information Service is currently not correcting the altimeters in mountainous areas (wind and terrain corrections) as there are no geographical conditions in Belgium where these corrections are required. In the AIP of Belgium and Luxembourg, section GEN.3.3.5 does not contain any corrections that need to be applied for determining minimum flight altitudes.

Supported data format processing in SkeyDrone Monitor

  • ARTAS cat62
  • SDDS cat48
  • ADS-B
  • ADS-B Light
  • Mode-S (Multilateration)
  • Remote Id
  • AIS vessel tracking

Compliance to standards

SkeyDrone’s solutions are compliant with the following standards:

  • ASTM Remote Identification F3411-19
  • ASD-STAN 4709-002 standard for Remote Identification
  • EUROCAE ED-129 standard for ADS-B ground receivers
  • EUROCAE ED-142 standard for Data processing MLAT (anti-spoofing processing) MLAT (anti-spoofing processing)
  • Commission Implementing Regulation (EU) 2019/947 on the rules and procedures for the operation of unmanned aircraft
  • Commission Implementing Regulation (EU) 2021/664 on the rules and procedures for the safe operations of UAS in the U-space airspace, for the safe integration of UAS into the aviation system and for the provision of U-space services
  • IEC 62320-1 Maritime navigation and radiocommunication equipment and systems – Automatic identification system (AIS)

Data fusion

Data from different sources is combined (fused) via a Kalman filtering technique. In the process, biases and other measurement errors are greatly reduced, resulting in a track that is much smoother than a single sensor track. Because of the identification of radar biases, there is no discontinuity (jump) when a track moves out of the coverage of one radar. And due to the higher rate of updates from multiple radars, the update on the radar screen can often be increased.