4 Availability Analysis of the Multilateration Surveillance System in Kiev (Boryspil) Airport

MRRS-2008 Symposium Proceedings. Kiev, Ukraine, September 22-24, 2008
Availability Analysis of the Multilateration Surveillance System in Kiev (Boryspil) Airport
Inna Konchenko
National Aviation University, Ukraine
inna_137@ Abstract— In this paper application of multilateration (MLAT) systems for vehicles localisation is considered. Deployments of such system require special algorithms to be developed and implemented. Analysis of multilateration system deployment is done for Boryspil airport in Kiev, Ukraine. With the help of calculation algorithms, different cases of target position inside the airport area are considered and brief analysis of detection is done. The simulation scheme is developed in order to obtain maximum accuracy of target localization.
of signal propagation, the reason of which in this case is only buildings.
I. INTRODUCTION Multilateration (MLAT) is the system, which can track an aircraft or another vehicle at airport. It operates via triangulation by means of measuring Time Difference of Arrival (TDOA) of transponder signal at multiple ground receivers sited at different locations. This system is considered as promising one for air traffic surveillance without active radars [1]. The main requirement for MLAT system is providing high accuracy of target localization at any weather conditions and airport placement. At the same time accuracy of coordinate measurements depends on the MLAT system geometry. Optimal arrangement of system and the number of receiver units vary depending of specific futures of each airport (multipath signal propagation, large buildings placement, airport capacity etc.). Therefore the aim of this work is investigation of target (vehicle) localization subject to system layout. II. SYSTEM GEOMETRY PLACEMENT IN BORYSPIL AIRPORT A configuration of multilateration system deployment needs to be provided by information of simulation results. A suitable analysis predicts, which level of accuracy can be achieved in different volumes for a given system configuration [2]. There are no difficult geographical conditions in Boryspil airport. But approaching, take off and safe landing must be provided even in inclement weather at low visibility. In our simulation fifteen passive receiving stations were situated around the airport and within the central terminal area conditionally. The origin of the coordinate system was placed not in the centre of the area (Fig. 1). Sensors’ positions were changed in order to obtain maximum accuracy of vehicle localization. In this simulation initial target coordinates are x=2500 m, y=900 m, z=2 m. Additional sensors can be added, either to overcome line-of-sight restriction, to improve geometry in certain areas, or to increase the overall surveillance volume. We took into account possible multipath
Fig. 1 Multilateration system layout in Boryspil airport
One single result allows the transmission to be located on a hyperboloid. Each TDOA value represents an arc. Intersection of all arcs indicates a target position. The distance between each pair of remote units (RU) is precisely known. Measured values of TDOA for RU1-RU15 pairs (with the help of calculation algorithm [3]) are compared with expected ones. Difference between actual and expected TDOAs may exceed the maximum value for propagated Track Position parameter threshold (taken value = 20 meters). This information is used to eliminate RU detections that may be corrupted by multipath (reflected signals take much longer time interval to reach a target than expected ones) [4].
Fig. 2 Absolute error varying depending on Remote Units groups
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