Night Vision Imaging System Compatibility
NVIS compatibility is one of the most crucial issues facing helicopter and military aircraft pilots today. Crew members equipped with Night Vision Goggles must be able to read their instruments without interference and at the same time non-NVG crew members must be able to see the same instrumentation. External lighting is no less important, whether for covert missions or when flying in formation.
The human eye responds to wavelengths between 400 and 700 nanometers (nm) on the electromagnetic spectrum. Diminished light diminishes our capability to distinguish color and detail. On dark nights the eye cannot distinguish colors and objects appear as shadowy shapes. NVIS technology has been developed in order to compensate for this phenomenon. Simply put, NVIS technology increases visible light and allows the human eye to see normally imperceptible radiation (Infra Red) as well as the ability to discern differences between colors. Today’s NVG technology allows the user to see a crisp image, even at low light levels. In addition, the sensitivity of NVIS to IR makes it far more useful for night vision than devices which only amplify visible light, such as a flashlight or telescope.
The success of an NVIS application depends, however, on the environment within which it is functioning. Because normal light sources emit significant amounts of IR radiation which fall within the response range of NVIS, the performance of a NVIS compatible cockpit is as important as the NVIS itself.
Aeromaoz, Ltd. (www.aeromaoz.com), with its team of optical, electrical and mechanical engineers, designs, develops and produces NVIS compatible light elements to the highest degree of NVIS compatibility. Incorporating custom designed filtering solutions into each individual application, Aeromaoz NVIS conversions eliminate the ghost images produced by canopy reflections, the halo-like glow around displays caused by goggle blooming and the degradation of sensitivity and resolution caused by the activation of the goggle automatic gain control.
Depending upon the application, non-NVIS elements can be upgraded to NVIS compatibility using a number of different solutions. The following solutions were all incorporated in conversion programs for the MI-17, MI-24, Cheetah, Sea King and Jaguar fighter in conjunction with the Indian Air Force / Indian Defense Force: replacement of illuminated panels with new NVG compatible illuminated panels, replacement of internal filters with NVG compatible filters, replacement of annunciators and indicators with NVG compatible equivalents or replacement of the internal lamp with an NVG compatible LED based lamp, or bezels, post lights or floods are added to the existing instrument panel. Cargo bay dome lights, utility and floodlights can all be replaced by NVG equivalents, as can external lighting applications which can be combined with IR illumination visible to NVG, but not to the human eye (critical for covert operations). External solutions are designed to utilize the existing infrastructure of the lighting so there is no need for changing the avionics of the aircraft. In addition, custom designed LED based solutions increase MTBF, lower power consumption and allow for simple replacement when necessary.
NVIS compatible elements are supplied individually, as kits ready for installation, or Aeromaoz can send its team of engineers to the site to do the actual installation. This last option allows the local technicians to learn and understand how to install a kit on an initial installation and then complete the other installations themselves, as has previously been done in India. With lighting programs installed on over 50 different platforms, military, commercial and business, Aeromaoz has the expertise to offer the solutions for any application.
Aeromaoz NVIS conversions are designed for both Type 1 (Direct View Image – phosphor screen image only, primarily rotary wing aircraft) and Type II (Projected Image – allows for viewing phosphor screen and cockpit instrumentation, primarily fixed wing aircraft) goggles, and both Class A (rotary wing) and Class B (fixed wing) filtering. By minimizing NVIS radiance, eliminating unfiltered light leakage, meeting color specifications and maximizing visible light transmission, Aeromaoz manufactures elements to MIL-L-85762A and MIL-STD-3009 specifications.