ACSA King Shaka International
Airport Bird Detection Radar System
Mount Moreland Barn Swallows
Radar has been used for detecting and monitoring bird
movements for over 60 years, however application of dedicated bird detection radars for managing aircraft
birdstrike hazards at airfields and airports has only undergone serious development focus over the past two
decades, primarily driven by needs of the military and advances in computer technology. The U.S. Air Force
(USAF) has been a leader in development of radar remote sensing systems for bird detection and avoidance,
supporting numerous significant projects to advance the level of the
Dedicated bird detection
radar systems today typically consist of multiple radar sensors, some with ancillary equipment and features
for enhanced functionality and automation. The most frequently used radar is a wide array antenna which is
preferred due to its lower cost, broad beam detection coverage, ease of use, and robust, proven reliability.
The most advanced systems on the market use dual scanning radar sensors consisting of a vertical scanning
radar (VSR) and a horizontal surveillance radar (HSR). The actual radar antennas are commercial off the shelf
products used primarily by the maritime industry and are mounted on most large ocean
The VSR operates in the X-band frequency, scanning
horizon-to-horizon through the vertical plane with the radar aligned with the runway to provide coverage of
the runway approach and departure corridors. In the vertical scanning orientation, the radar is turned on its
side so that it scans a vertical slice through the atmosphere detecting hazardous bird activity in on and
above the runway and in the critical runway corridors from the ground level to aircraft operational
altitudes. The VSR radar sends out a fan-shaped beam and, depending on power, can reliably detect bird targets up to 3-4 nautical miles (nm) to
either side of the radar and to 15,000 feet (ft) above the runway. The HSR operates in the S-band frequency
concurrently with the VSR, scanning 360 degrees around the airfield detecting and tracking bird activity from
the ground level to aircraft out to 6-8 nm.
The combined vertical and horizontal scanning configuration in
MERLIN provides the maximum level of coverage in a cost effective manner with specific, dedicated 3D coverage for
the runways and approach and departure corridors where 85% of airfield and airport bird strikes
Combined, the HSR and VSR beams deliver optimal detection of hazardous bird activity in a
cost-effective package that includes detection and tracking of birds at the lower altitudes (under 500ft)
where 85% of commercial bird strikes occur. The VSR additionally provides precise altitude information that
can be used by controllers to more effectively manage risk in the most critical runway approach and departure
corridors and along the runway.
The analogue radar signal gets converted to a digital
format by specialised computer graphics hardware. Custom developed radar
software programs are then used to track targets (birds).
The bird radar in use at the King Shaka International
Airport is a Merlin XS2530i Aircraft Bird Avoidance Radar supplied by DeTect Inc. a USA based company that
specialises in the development of proprietary bird detection radar systems for the aviation
Due to the unique nature of the Barn Swallow flocks near to KSIA DeTect developed a Swallow Detection
Algorithm (SDA) that tracks the movements of the swallow flocks in the early mornings and late
afternoons. The SDA also generates advisory warnings which can then be relayed directly to aircraft via
the radar operator and the air traffic controller.
During the early mornings
and late afternoons high resolution data from the radar are being recorded for continued analysis of the
behaviour of the barn swallows.
All the radar data collected since 2007 indicate that
the airport and the Barn Swallows that roost at Mount Moreland can
easily co-exist. The time intervals during
which the swallows could potentially pose a risk to aviation are short in duration and
predictable. The fact that the bird detection
radar information will provide an advisory to air traffic control will ensure that pilots receive timeous
information regarding the bird strike risk.
Airport operations will thus take the barn swallows into consideration ensuring a co-existence between the
airport and the swallows.
This will be the first commercial airport where information from a bird detection radar
will be used actively by air traffic controllers to warn pilots of current bird strike
The KSIA bird radar also tracks the movement of other
bird species and provides a detailed overview report to bird and wildlife staff on a daily
basis. This further enhances the ability of the bird and wildlife department to understand bird
behaviour and risks on and around the airfield and how best to align their scaring