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| Offshore Wind Turbines |
NATS and Terma Team Up to Develop Airport Radar to Mitigate Impact of Wind Turbines
New airport radar to mitigate impact of wind turbines | NATS[Avionics Today 10-10-2014] NATS has released a statement detailing a single radar that can provide traditional airport surveillance functions and mitigate against the effects of wind turbines. NATS reports that the technology may be a step closer to deployment, following trials conducted through 2014.
Between January and March of this year, the Air Navigation Service Provider (ANSP) along with the radar manufacturer, Terma, conducted trials of Terma’s SCANTER 4002 system to assess its performance as an extended range wind turbine mitigation system. Initial results indicate that the system is both capable of mitigating the effects of wind turbines and detecting aircraft through wind farm locations, even at ranges beyond 40 nautical miles (nm).
Following this successful initial trial, the radar was evaluated during August by the Civil Aviation Authority (CAA) as part of its Spectrum Release Program. The results confirmed that the system is capable of detecting even small targets beyond 40 nm and with good low-level coverage. Based upon these initial positive results, further testing is expected with the CAA moving forward.
Iain Harris, NATS Director of Engineering, Services, said: “We’re committed to working with a range of developers and radar manufactures to find the best way for airports to mitigate the impact of wind turbines. These latest trials with TERMA represent a breakthrough for airport operations, adding to our progress we have already made in the en-route environment.
Michael Agergaard Riis at TERMA added: “Our solutions are based on well-proven products designed for mission-critical applications which enable us to minimise risk and respond quickly to customers’ needs. The recent trials together with NATS have further strengthened our belief that the SCANTER 4002 radar is a very capable solution for single radar wind farm mitigation.”
Uploaded on Dec 21, 2011
The following image sequence shows
primary radar video with track overlay of a small aircraft over Horns
Rev offshore wind farm using Terma SCANTER 4002 Air Surveillance Radar.
Tracking is based on primary radar video only - SSR data was not used
during the test.
Terma SCANTER 4002
The SCANTER 4002 Transceiver is designed for detection and separation of small air targets and large surface targets like wind turbines. To achieve simultaneous good performance for air and surface detection, the SCANTER 4002 radar system is designed as a two-dimensional coherent X-band radar with pulse compression and advanced MTI processing, which provides enhanced detection of small air targets.
Interturbine Visibility
The high transmit power and receiver dynamic range (+110 dB) of the SCANTER 4002 combined with low range and antenna side lobes provide superior detection of small air targets, like e.g. general aviation aircraft and helicopters, without degraded sensitivity in and around the wind farm. High resolution CFAR processing enables target detection and tracking between turbines.
Instrumented Range
Utilizing state of the art processing technologies, the SCANTER 4002 enables efficient and cost-effective detection of even very small targets. The instrumented range of the SCANTER 4002 air coverage is up to 90 NM and the radar system can be configured with different antenna systems, e.g. 15 ft, 18 ft or 21 ft, depending on the requirements.
Additional information
IEEE Explore search on Terma SCANTER Radar in last 10 years
Hansen, K.; Thomsen, A.C.K.; Riis, M.A.; Marqversen, O.; Pedersen, M.O.; Nielsen, E., "Detection and tracking of aircraft over wind farms using SCANTER 4002 with embedded tracker 2," Radar Systems (Radar 2012), IET International Conference on , vol., no., pp.1,6, 22-25 Oct. 2012doi: 10.1049/cp.2012.1644
Abstract: Test results of aircraft detection and tracking over large offshore wind farms show that a track can be maintained on a light manoeuvring aircraft as well as general aviation aircraft using an off-the-shelf radar solution. The optimum strategy of mitigating the deteriorating effects of closely spaced wind turbines on air surveillance is shown to depend on the characteristics of the wind farm, in particular the density of the wind turbines.
keywords: {Air traffic control;radar;tracking;wind farms},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6494800&isnumber=6494711
Pedersen, M.O.; Hansen, K.; Thomsen, A.K.; Lokke, M., "X-band surveillance radar antenna with integrated IFF antenna," Radar Conference (RADAR), 2011 IEEE , vol., no., pp.172,174, 23-27 May 2011
doi: 10.1109/RADAR.2011.5960522
Abstract: A compact, low profile, low weight radar antenna is presented combining a primary radar antenna operating in the X-band with a secondary L-band antenna for integrating primary and secondary (IFF) radar surveillance in a single antenna.
keywords: {microwave antennas;radar antennas;surveillance;X-band surveillance radar antenna;integrated IFF antenna;low weight radar antenna;primary radar antenna;single antenna;Antenna feeds;Antenna measurements;Antenna radiation patterns;L-band;Radar;Radar antennas},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5960522&isnumber=5960475
Moller-Hundborg, C.T.; Thomsen, A.C.K.; Marqversen, O.; Hansen, K.; Pedersen, M.O.; Lokke, M., "Small target detection with SCANTER 5000 & 6000 radar series," Radar Symposium (IRS), 2011 Proceedings International , vol., no., pp.403,408, 7-9 Sept. 2011
Abstract: In a world with asymmetrical threats, detection of small targets is the overall scope of a surveillance radar. This detection capability is required in extreme environments and in heavy weather conditions; hence the need for adaptation to the surroundings. In urban areas with an increasing radio infrastructure, interference from and against other systems is an important parameter, while reliability and required maintenance is important in rural areas with remote sites. At sea, sub clutter visibility and adaptation to a moving platform are important parameters. This paper describes how the technology platform of the SCANTER 5000 and 6000 transceivers complies with the above-mentioned parameters through a system description and demonstrated radar performance.
keywords: {interference (signal);object detection;radar clutter;radar tracking;SCANTER 5000 radar series;SCANTER 5000 transceivers;SCANTER 6000 radar series;SCANTER 6000 transceivers;interference;radio infrastructure;subclutter visibility;surveillance radar;target detection;Chirp;Clutter;Frequency diversity;Frequency modulation;Radar;Sea measurements;Signal processing algorithms},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6042142&isnumber=6041611
Lokke, M.; Ostergaard, A., "Accurate synthesis of linear non-resonant narrow wall inclined slotted waveguide arrays," Microwaves, Antennas & Propagation, IET , vol.5, no.13, pp.1646,1653, October 2011
doi: 10.1049/iet-map.2010.0443
Abstract: An efficient and highly accurate network model for analysing and synthesising large but finite slotted waveguides (SWGs) is presented. The network model is tailored for arrays of linear end-fed narrow wall inclined slots. The network model accurately predicts, as function of frequency, the key electrical antenna parameters such as antenna-radiation pattern (beamwidth, inner and spurious sidelobes down to the -40-dB level, main beam squint), waveguide loss, power dissipated in the load and return loss. The network model explicitly takes mechanical tolerances into account. The model is based upon S-parameter measurements of a number of test-SWGs. The network model has been proven to be scalable from X-band to S-band waveguides and can be extrapolated to slot parameters far beyond the range of the slots of the test-SWGs. The comparison between predicted and measured results has shown that the network model is highly accurate, providing a significant improvement over full wave commercial tools in terms of prediction of the antenna parameters of interest as well as in computational speed.
keywords: {S-parameters;antenna radiation patterns;slot antenna arrays;S-parameter measurements;accurate synthesis;antenna-radiation pattern;linear nonresonant narrow wall inclined slotted waveguide arrays;waveguide loss},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6086880&isnumber=6086863
Thomsen, A.C.K.; Marqversen, O.; Pedersen, M.O.; Moeller-Hundborg, C.; Nielsen, E.; Jensen, L.J.; Hansen, K., "Air traffic control at wind farms with TERMA SCANTER 4000/5000," Radar Conference (RADAR), 2011 IEEE , vol., no., pp.247,252, 23-27 May 2011
doi: 10.1109/RADAR.2011.5960537
Abstract: The challenges of aircrafts detections in the area of wind farms are addressed. Requirements for a gapfilling radar solution is identified and obtained performance with SCANTER 4000 and SCANTER 5000 are described.
keywords: {air traffic control;radar applications;wind power plants;air traffic control;aircrafts detections;gapfilling radar;terma SCANTER 4000;terma SCANTER 5000;wind farms;Antennas;Azimuth;Poles and towers;Radar cross section;Wind farms;Wind turbines},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5960537&isnumber=5960475
Pedersen, J.C., "SCANTER 5000 and 6000 Solid State Radar: Utilisation of the SCANTER 5000 and 6000 series next generation solid state, coherent, frequency diversity and time diversity radar with software defined functionality for security applications," Waterside Security Conference (WSS), 2010 International , vol., no., pp.1,8, 3-5 Nov. 2010
doi: 10.1109/WSSC.2010.5730272
Abstract: Coherent, Solid State Radar technology has been available for decades, however, it did not penetrate into harbor surveillance, VTS and related applications for cost and technical reasons. Technically, the main challenge is that dynamic requirements to radar in littoral waters and build up regions are much higher than to other radar applications. Those challenges have now been met and combined with well-renowned advantages from the Terma SCANTER product range. Methods are further refined and implemented on a new technology platform. The result is a software-defined radar series, tailored to individual market segments, virtually unrestricted by dynamic constraints. The digital radar concept with software-defined functionality makes the set-up of the radar easy. Furthermore, Interference rejection against disturbance from radars on ships passing nearby the radar has also proven effective, and the dynamic range has proved to be sufficient to eliminate any artefacts from a high number of large buildings and other structures in an operational area. Operational tests have been performed with impressive results.
keywords: {interference suppression;search radar;SCANTER 5000 solid state radar;SCANTER 6000 solid state radar;Terma SCANTER product range;VTS;coherent radar;digital radar concept;frequency diversity radar;harbor surveillance;interference rejection;littoral waters;next generation solid state;operational tests;security applications;software defined functionality;software-defined radar series;time diversity radar;Antenna measurements;Radar antennas;Radar cross section;Radar imaging;Solids;Coherece;Frequency Diversity;Radar;Radar Cross Section;Sector Power;Security Applications;Software-Defined Functionality;Solid State;Time Diversity},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5730272&isnumber=5730220
Thomsen, A.C.K.; Ostergaard, A.; Marqversen, O.; Moller-Hundborg, C.T.; Jensen, L.J.; Rohde, R.H.; Leth-Espensen, P., "SCANTER 4000/4100: A multi purpose surveillance radar," Radar Systems, 2007 IET International Conference on , vol., no., pp.1,4, 15-18 Oct. 2007
Abstract: This paper presents the background for and the main features of the multi purpose SCANTER 4000 and SCANTER 4100 surveillance radar systems, recently being developed at Terma A/S for air and sea surveillance. The SCANTER 4000 system is for stationary applications, while the SCANTER 4100 radar system is intended for use on a moving platform, e.g. a vessel. The paper describes the highlights in terms of the measured performance obtained and gives an overview of the radar system.
keywords: {Surveillance radar;artificial lens;calibration topology;clutter suppression;timesidelobes},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4784112&isnumber=4784008
Ostergaard, Allan, "Scanter 4000/4100: Synthesis, design and manufacture of an artificial lens for an air surveillance antenna," Radar Systems, 2007 IET International Conference on , vol., no., pp.1,4, 15-18 Oct. 2007
Abstract: The synthesis and design of a metallic lens in the aperture of a large flared horn antenna is reported. The lens provides sufficient correction of the quadratic phase error in the aperture of the horn to obtain ample antenna gain, while it simultaneously shapes the phase in the aperture such that a modified cosecant squared far-field pattern is obtained in the cross-sectional plane of the flared horn. The reflection from the lens due to the incident cylindrical wave (propagating between the flares of the horn) shall be weaker than -25dB to maintain a stable antenna pattern within the desired bandwidth. Otherwise, the amplitude and of phase distribution in the aperture of the horn will be pertubed by the reflected field (returning subsequent to reflections from the inner surfaces of the horn). The aperture distribution would then be strongly dependent upon the exact location of the lens (located in the vicinity of the aperture). As the depth of the horn is 44 wavelengths, the perturbations due to the reflected field from the metallic lens would also become highly frequency dependent. A low reflection off the lens thus relaxes the mechanical requirements of its exact location, and is as such a prerequisite for a sucessful electrical design and for the series production of the antenna.
keywords: {Metallic lens;cosecant squared pattern;full-wave;synthesis},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4784138&isnumber=4784008
Kim Hansen Systems Engineer at Terma A/S
@David Stupples. More details on the radar sensor in itself is given here in this 2011 paper:
http://www.terma.com/media/155654/3069_air_traffic_control_at_wind_farms_with_terma_scanter_4000_5001.pdf
http://www.terma.com/media/155654/3069_air_traffic_control_at_wind_farms_with_terma_scanter_4000_5001.pdf
The requirements needed to get aircraft detectability in the area and vicinity of wind farms are discussed and quantified [in this paper]. The requirements have been compared with the actual performance of the Terma developed and produced radar series SCANTER 4000 and 5000 to justify their capabilities in this aspect. Actual recorded inter-turbine detection has been shown and the benefits of this solution compared to an upgrade solution of standard ATC radars are provided. It should be noted that SCANTER 4000 family is an off-the-shelf products that was installed at a customer for the first time in 2007 and now sold to 6 nations. SCANTER 5000 is a newly developed family of solid state based radars aimed for different applications [8] where SCANTER 6000 is a variant of the SCANTER 5000 complemented with functions for being installed on moving platforms.
Previously
spendergast: Predicting and Surveying Potential Wind farm Sites for radar interferenceAir Force looks to solve wind farm radar interference -- Defense Systems
Air Force eyes modeling software to understand how wind farms create radar dead spots - Military & Aerospace Electronics
Kim Hansen Systems Engineer at Terma A/S
IET Digital Library: Detection and tracking of aircraft over wind farms using SCANTER 4002 with Embedded Tracker 2
Here is a direct link to the PDF for your convenience:
Since these results have been published there was been incremental improvements to the product as a large series of elaborate and succesful tests on off-shore and land-based wind farms have been conducted in the US and the UK
Some key success factors: X-Band pulse-compression radar, 60 dB peak side-lobe ratio, and an excellent tracker