Prof. dr. sc. Ivan Markežić ivan.markezic@fpz.hr Универзитет „Св. Климент Охридски“ Технички Факултет – БИТОЛА МУЛТИРАТЕРАЦИЈА КАКО ТЕХНИКА НА КОНТРОЛА НА ВОЗДУШНИОТ СООБРАЌАЈ MULTILATERATION AS SURVEILLANCE CHOICE Prof. dr. sc. Ivan Markežić ivan.markezic@fpz.hr MULTILATERACIJA KAO TEHNIKA KONTROLE ZRAČNOG PROMETA

Air Traffic Surveillance – Techniques and Technologies Content Air Traffic Surveillance – Techniques and Technologies Multilateration System Description Multilateration in an ECAC Context Conclusion Područje elektrotehnike

”In The Beginning” atc6.AV Područje elektrotehnike

Air Traffic Surveillance – Techniques and Technologies Područje elektrotehnike

Air Traffic Surveillance – Techniques and Technologies Principle of Multilateration Područje elektrotehnike

Surveillance strategy: Air Traffic Surveillance – Techniques and Technologies Surveillance strategy: - mutually interoperable and compatible technologies MSSR/SSR Mode S ADS-B Područje elektrotehnike Multilateration, WAM

MLT System Description Principle of Multilateration Područje elektrotehnike multilat_princip.avi

MLT System Description Principle of Multilateration Co-operative Independent Surveillance - a number of antennas receive a signal from an aircraft - central processing unit calculates the aircraft’s position from the time difference of arrival (TDOA) of the signal at the different receivers - the TDOA between two antennas corresponds with a hyperboloid, a 2D surface in a 3D space - at least four antennas are required for a 3D position calculation - if altitude is known already, three antennas are sufficient Područje elektrotehnike

MLT System Description Active and Passive WAM System Passive WAM Systems No transmitter means: - No transmitter license - No 1030 spectrum usage - No increase to 1030/1090 SSR environment (FRUIT) Aircraft detection requires: - The aircraft is Mode S equipped or - The aircraft is within existing MSSR coverage Područje elektrotehnike

MLT System Description Active and Passive WAM System Active WAM Systems Independent of existing infrastructure - Improved detection of Mode A/C only aircraft Simpler and cheaper than MSSR interrogator - Fixed antenna - Low power interrogation option Suitable for Mode S Surveillance Care must be taken not to generate excess 1030/1090MHz FRUIT Područje elektrotehnike

MLT System Description WAM performance Multilateration and Wide Area Multilateration Multilateration - Independent cooperative surveillance Surface Multilateration - Tracks aircraft on the surface - Uses 2D algorithms Wide Area Multilateration - Tracks aircraft in flight - Uses 3D algorithms Područje elektrotehnike

MLT System Description WAM performance (en route application) MSSR WAM Područje elektrotehnike A 5 receiver WAM system with a 60nm baseline gives: - Higher accuracy than MSSR - Reduced range due to horizon effect

MLT System Description WAM performance (en route application) Područje elektrotehnike A 9 receiver WAM system with a 60nm baseline gives: - Higher accuracy than MSSR - Similar range to MSSR Horizon effect (WAM horizon is the horizon of multiple sites)

MLT System Description WAM performance (TMA application) Područje elektrotehnike Coverage at 3000ft : - Larger baselines give better accuracy Shorter baselines give better low level coverage

MLT System Description Impact on existing ATM operations There is no negative impact on existing ATM operations - WAM systems can easily be integrated into current ATM architectures - WAM systems can exceed the performance of existing surveillance sensors - There need be no difference in the information presented to the controller WAM systems could provide benefits to ATM operations in the future - WAM systems are capable of higher accuracies than current sensors - WAM systems are capable of higher update rates than current sensors - WAM systems can measure geometric height in addition to receiving pressure altitude Područje elektrotehnike

Multilateration in an ECAC Context Eurocontrol is promoting WAM technology for ATC surveillance: (relatively low cost and good performance) Područje elektrotehnike Ground based surveillance infrastructure for En-Route and TMA

Multilateration in an ECAC Context Područje elektrotehnike Surveillance Strategy at the Aerodrome ADS-B/WAM Combination - future surveillance scenario (!?)

En-route WAM systems can also provide accurate height measurement Conclusion WAM systems are potentially capable of significantly higher accuracies than an equivalent radar service: a five receiver WAM system has a higher accuracy than MSSR (both an en-route and terminal ) The range is lower due to the horizon of multiple receivers A comparable range can be achieved by adding in additional receivers En-route WAM systems can also provide accurate height measurement information All current WAM systems are based on 1090 MHz technology because: wide availability of the technology as part of the airborne infrastructure The properties of these signals for use in a WAM system (aircraft identification and accurate TDOA measurements) Područje elektrotehnike Provide ADS-B data in addition to independent position Do not require additional avionics Ref.: The ATM Surveillance Strategy for ECAC, 2.2, ed. date 07/04/2008. http://www.eurocontrol.int/surveillance/gallery/content/public/documents/WAM_study_report_1_1.pdf

ВИ БЛАГОДАРАМ НА ВНИМАНИЕТО Područje elektrotehnike