The objective of the Ismael project is to determine whether recent advances in magnetic sensors could provide a better means of surface movement surveillance at airports, either as a cost-effective alternative to Surface movement radar (SMR) for smaller airports or as an additional point sensor in multi-sensor Advanced surface movement guidance and control systems (A-SMGCS) at major international airports. Therefore a new detector technology shall be developed and integrated into advanced surface movement guidance and control systems (A-SMGCS).
The detection of targets moving on the airport surface is achieved by detecting their ferromagnetic parts such as vehicle motors or aircraft engines and gears, based on their interaction with the earth's magnetic field. This property can be used to detect and locate objects, either using a single point detector or an array of detectors.
A system based on an array of detectors can provide reliable object velocity and direction information unaffected by weather conditions, shadowing or reflection effects. Also, the proposed system has the ability to classify detected targets into two main classes i.e. aircraft and cars. Detection ability of magnetic detectors is not influenced by weather, temperature and brightness. The system based on magnetic detectors is passive (non-cooperative), has low power consumption, no radiation and no influence to airport communication.
Magnetic detectors have been tested in Thessaloniki airport and Frankfurt airport for runway incursion, tracking and gate management. Systems based on magnetic detectors may serve as 'gap filler' for areas where existing surveillance techniques are not effective, or as a low-cost alternative to radar or multi-lateration at smaller airports. The solution is also very appropriate for the prevention of runway incursions.
The SDF (sensor data fusing) software collects data about the state of magnetic detectors that are connected to the SDF server in real time and processes this data in order to extract observations (plots) and tracks. It provides information about the position and speed of targets, the date and time of detections and the size of the targets. The communication between SDF server and the network of magnetic sensors is based on the RS-485 protocol.
The final results of the SDF software are encoded in Asterix Cat.10 format and are transmitted as UDP Ethernet packets. An optional visualisation window is also available, showing detector states (inputs) as well as generated observations and tracks on the airport map. One of the benefits of the proposed approach is that it addresses a problem associated with the standard two-dimensional (2D) constant velocity (CV) motion model, i.e. that it allows each target to move freely within the ground plane.
A software package, Test analysis client, for statistical analysis of test results was designed and implemented as part of Ismael project. The software analyses data provided by the magnetic detection system, compares it to an external reference source, determines the probability and quality of detection, and correlates the statistics with environmental factors, time, and system relevant parameters.
