Night Vision Goggle Compatible Infrared LED Obstruction

INFRARED LED Aviation Obstruction Lights
Page 1 | 2
September 4, 2014
Night Vision Goggle Compatible
Infrared LED Obstruction Lights
Obelux Oy, Kutomotie 6 B, 00380 Helsinki FINLAND | The information in this document is subject to change without notice. © Obelux Oy 2014
WWW.OBELUX.COM
Figure 1. Optical design has an important role in NVG compatible
infrared lights.
Figure 2. LED obstruction lights with suitable infrared wavelength
are visible to different types of NVGs.
Civil Aviation Authorities (CAA) all over the world
are taking actions in new infrared regulations for
aviation obstruction lights. They are making it
mandatory to include infrared wavelength to LED
based obstruction lights.
Aviation red color ranges from about 610 to 660
nanometers (nm), and many NVGs are only
sensitive to energy ranging from 665 to about 930
nm. Due to the fact that LEDs have a relatively
narrow emission band and do not emit infrared
energy like incandescent lights, it is possible for
those to meet International Civil Aviation
Organization (ICAO) standards but still be below
the range in which NVGs are sensitive.
In recent years, a safety threat has been raised
by several CAAs all over the world regarding
Night Vision Goggles (NVGs) and LED aviation
obstruction lights. Typical LED lights are clearly
visible to the naked eye but not to NVGs. The
reason for this is that aviation red and aviation
white color LEDs produce wavelength below the
NVG’s sensitivity spectrum.
International Standards for Obstruction Lights
ICAO International Standards and
Recommended Practices: Aerodromes Annex 14
Volume 1, 5th Edition, July 2009, Chapter 6
FAA Advisory Circular AC 150/5345-43G
Figure 3. Obelux infrared lights’ peak wavelength is at 855nm
INFRARED LED Aviation Obstruction Lights
Page 2 | 2
September 4, 2014
Night Vision Goggle Compatible
Infrared LED Obstruction Lights
Obelux Oy, Kutomotie 6 B, 00380 Helsinki FINLAND | The information in this document is subject to change without notice. © Obelux Oy 2014
WWW.OBELUX.COM
Many Countries Have Made Infrared Obstruction
Lights Mandatory
Aviation obstruction light regulations have been
updated in many countries all over the world,
due to the infrared light issue. The new
regulations typically apply to all new and
replaced obstruction lights based on LED
technology installed on any kind of structure. The
new specifications typically take into account
the light output [mW/st], vertical beam angle [°],
flashing sequence [fpm] and specific
wavelength [nm] of the infrared light.
Figure 4. Infrared light can be incorporated to different types of
obstruction lights making them NVG compatible.
Too Strong Infrared Intensity Causes Negative
Halo Phenomenon
The power output of the infrared light is very
critical characteristic as it first needs to provide
sufficient output to be visible for NVGs but on the
other hand it is very important that the maximum
power output is limited because too strong
intensity causes optical phenomenon called
halo. This halo phenomenon can have a
significant negative effect on to the observations
made by a pilot using NVGs.
Figure 5. Pilot’s view through Night Vision Goggles from
a helicopter.
NVG Compatible Obstruction Lights by Obelux
Obelux infrared lights are tested and approved by Air Forces from different
countries. The best performance of the lights is first tested on extensive field
tests and then verified by a third party laboratory. All Obelux NVG
compatible infrared obstruction lights are visually marked with the “NVG
Compatible” -sticker both on the product and on the package.
Obelux Oy
Obelux Oy designs manufactures and sells ICAO and FAA compliant LED
aviation obstruction lights. As one of the oldest companies in the world
focusing only on LED technology, Obelux has built a reputation for high
quality, reliability and low life-cycle costs.