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Obstruction Light Control

Terma’s Obstruction Light Control (OLC) vastly reduces light pollution, and increases public acceptance of wind farms.


Radar-based Obstruction Light Control*

We make sure that the obstruction lights are turned on only when necessary, i.e. when an aircraft is nearby. The majority of the time when the obstruction lights are not needed, they will stay off. 

*ADLS (Aircraft Detection Lighting Solution) is the North American abbreviation of OLC (Obstruction Light Control)


OLC introduction 464Terma’s Obstruction Light Control (OLC) vastly reduces light pollution, and increases public acceptance of wind farms


Reducing light pollution

Turn obstruction lights on – but only when needed. The increasing size of wind turbines is creating safety and societal challenges for the wind industry, the authorities, and the surrounding municipalities when it comes to complying with air traffic regulations.

As wind turbines grow taller and enter the lower airspace, high intensity obstruction lights are needed. The high-intensity lights required for higher wind turbines can appear very intrusive to wind farm neighbors and to an otherwise pristine night sky. The high intensity lights cause a growing number of delays and cancelations of wind farms due to complaints from neighbors and municipalities near planned wind farms. These problems can be overcome by turning the obstruction lights on only when necessary, i.e. when there is an aircraft in the vicinity of the wind farm. Terma’s Obstruction Light Control (OLC) vastly reduces light pollution caused by wind farms and improves the success rate of wind farm deployments.



Terma has an extensive track record with approval authorities providing documentation, standard safety cases, and support. Terma’s know-how and domain leadership can be of great benefit in the approval process for planning and operational permits. Working with Terma is a long-term partnership from the approval process through to deployment or retrofit of the wind farm.

Terma’s OLC solution is the most widely approved solution, and certified for deployment in the following countries;

  • United States, certified by the FAA (Federal Aviation Administration)
  • Germany, certified by DFS (Deutsche Flug Sicherung)
  • Denmark, certified by TBST (Danish Transport, Construction and Housing Authority) 


Proven and reliable technology

Terma has been a world leader within radar detection technologies for more than 60 years. Our +3,000 Terma radar systems are protecting borders, harbors, airports, coast lines and wind farms worldwide. More than 85% of all major airports around the world and 65% of all coastal shores rely on Terma’s radar technology.
Terma’s OLC solution is based on our proven and reliable technology, ensuring continuous operation and low maintenance costs. Combined with our global service and maintenance capability, you obtain a proven high-performance system with very low risk.


Terma Lifecare

We take care of your products - know your Total Cost of Ownership at purchase.
We ensure that your radar solution is maintained to minimize risk of downtime and keep your radar solution running in perfect conditions to protect your investment.


Turn obstruction lights on – but only when needed

Our proven radar capabilities within radar surveillance provide a confident solution for small target detection in all weather conditions. This means that small aircraft, helicopters, gliders, ultralights, and other small non-cooperative targets will be warned by the obstruction lights.
Terma’s built in target classifier is on the forefront of adaptive machine learning, to discriminate small non-cooperative targets from larger flocks of birds. This means that larger flocks of birds will not activate the obstruction lights. Birds’ not activating the obstruction lights on near- and off-shore windfarms is of great importance, not only to the neighbouring municipalities, and environmental bodies, but the birds too. Large flocks of birds are drawn to activated obstruction lights, greatly putting the life of the flock at risk. 


Key benefits

  • Vendor-neutral. Terma’s OLC solution integrates with existing infrastructure and lighting from leading Wind Turbine Generator vendors. 
  • Scalability / Deployment flexibility. Terma radar capabilities and deployment offerings enable flexible solutions, for on-shore, near-shore, and off-shore wind farms, bringing down the total cost of ownership. 
  • Terma’s SCANTER 5202 is a commercial of the shelf product with more than 300 installations in service.


OLC benefits 464The high intensity lights required for higher wind turbines can appear very intrusive to wind farm neighbors and to an otherwise pristine night sky.


Sustainable energy

We need to implement more sustainable energy for a future less dependent on fossil fuels, and wind energy is a great contribution to a sustainable energy grid. At Terma, we have solutions to support the implementation of more wind energy, and at the same time reduce the visual pollution caused by wind farm obstruction lights. 


Turn obstruction lights on – but only when needed

Terma’s SCANTER radars have fully digital signal processing and Solid State technology, providing extremely clear radar images with low probability of false alarms. Our SCANTER radars detect non cooperative targets such as small aircraft, including ultralights and birds in any conceivable weather condition. Therefore, obstruction lights are turned on only when needed. 

OLC functionality 464Terma's radars can truly co-exist with wind turbines without the need for blanking out wind farm areas



Our OLC solution provides 360 degree coverage (24/7) of up to 2,100 km2 of wind farm surveillance. SCANTER radars for our OLC solution have an instrumented range of up to 26 km detection radius, making our solution ideal for both small and large wind farms. For wind farms with a scattered layout, and to accommodate for future developments and expansions of the wind farm, additional SCANTER radars can be added.



The scalability and flexible positioning of the SCANTER radar to mitigate multiple wind farms with a single radar is important to bring down the total cost and provide scalability to grow with future expansion of the wind farm.


Product sustainment

The Terma SCANTER radar family has proven its performance, reliability, and sustainability in security applications all over the world. Based on Terma’s vast know-how and leading hardware and software technology, SCANTER radars provide our clients with a proven platform ensuring high availability (High Meantime Between failure).


Service & Support

At Terma, we know the importance of keeping the blades spinning. That is why we offer global Support & Service Agreements for up to 25 years, supporting long time sustainability and obsolescence management of our SCANTER products throughout the life time of the wind farm.