Current stage of bird radar systems Felix Liechti, Swiss Ornithological Institute Hans van Gasteren, Royal Airforce of The Netherlands IBSC Cairns 2010
Swiss Ornithological Institute a private foundation for the study and protection of birds founded in 1924 Sempach, Luzern 95 staff, corresponding to 70 full-time jobs budget 14m Swiss franc To IBSC on the behalf of the Swiss Civil Aviation Authorities
Radarsystem in use for monitoring bird migration military surveillance radar civil weather radar
Filtering bird echoes from a noisy environment
Example of large scale bird monitoring with weather radar
German Bird Radar Observation Network CRC HADR MPR RRP117 RRP117 CRC CRC MPR RRP117 CRC MPR RRP117 HADR RRP117 AWGeophys Traben Trarbach CRC CRC HADR MPR CRC HADR MPR CRC by Wilhelm Ruhe, GMGO
Flight restrictions for military aviation en-route bird strike prevention, based on large scale measurements. Flight restrictions (BIRDTAMS) limited real time bird density information available vulnerable: dependent on human expert interpretation need for good predictions: migration models & data assimilation
Requirements for civil aviation Reduction of birds-strikes in the vicinity of the airport, either by keeping birds off the critical areas or by redirecting the flight path of an aircraft. Local radar surveillance on and near airport can provide: improved selective bird control activities (BCU). real time warnings for aircrafts flying into the track of birds.
Radar for airport and near airport surveillance System requirements: Automatic localisation of bird strike risks in time and space. Information to bird control units to coordinate management. Information to ATC to direct approach and take-off
Radar for airport and near airport surveillance System perfomance: continuous surveillance of the relevant airspace. extraction of birds and positioning (tracks). calculation of collision risks by integrating extrapolated tracks of aircrafts and birds. automatic collision warnings in real time.
General performance of existing bird radar system Up to know almost all commercially available systems are based on marine radar systems, equipped either with a T-bar antenna or a parabolic dish antenna. T-bar antenna height=? vertical plane horizontal plane ~1 ~20 Dish antenna ~2-5
General performance of existing bird radar system Due to the large opening angle in the vertical plane, the height of an echo cannot be properly determined. In all available systems a second radar is used to collect height information. The following solutions are available: -Vertically rotating T-bar antenna provides a height distribution. 3D postioning of single targets not possible. -A second radar (dish or T-bar) is pointed towards selected echoes. Per time interval, only one echo can be tracked. 3D positioning of single targets possible.
General performance of existing bird radar system Horizontal surveillance mode allows to... monitor general bird activity Support for bird control unit 3D tracking of single targets Accurate flight paths of selected echos available Applicable for real time warnings.
Detection and identifcation
Detection and identifcation Discrimination factors -echo intensity -Groundspeed / airspeed -Doppler + - variation of echo intensity, (with continuous tracking)
Tracking example Accurate target identification: Amplitude Songbird, wingbeat frequency = 14.5Hz insect wingbeat pattern Time
Classification based on wing beat patterns (single birds!) FFT songbird - type 11.3 Hz swift - type 8.0 Hz waterfowl - type 7.9 Hz
Detection and identification Can be a difficult task!
Combination of different technics - Radar - Infrared - Lidar -?
Open problems A bird radar system must be approved and calibrated. To see some birds is not enough. Rate of proper detection and identification must be investigated. false alarm rate It must be achieved that all relevant targets are tracked in 3D.
Open questions What range of surveillance is needed around the airport? detection range of the radar system Which size of a bird and/or what number of birds (flocksize) is a relevant collision risk? identification skills of the radar system. Who will use this information when available? Bird control + ATC?
Conclusions 1. The technique to monitor birds and bats on an airport exists. 2. The final bird recording system, which we are aiming for, does not yet exist. 3. Precursor system do exist and are suitable to improve the work of the Bird Control Units. 4. The technical challenge for an automated real time warning system seems to feasible. 5.But, the integration of such a system in the safety management system is probably the most difficult, but also the most important challenge.