Northrop Grumman Electro-Optical Systems (NGEOS) has concentrated in recent years on the development of advanced night vision goggle (NVG) systems. These NVGs developments concentrate on past operational deficiencies such as high light/bright source conditions during military operations in urban terrain (MOUT), poor individual movement technique (IMT) infantry operations, and obscured battlefield and reduced weather conditions. The first area of NVG advancement involves direct image intensifier (I2) replacement involving automatic gated power supply technology for wide dynamic NVG operation and advanced Generation III halo free I2 technology for reduction of NVG image halo and “blooming” artifacts.
The second significant development area is NVG individual movement technique (IMT) deficiencies such as reduced field of view, reduced depth perception, center of gravity problems, and limited operation flexibility. These issues of NVG IMT have resulted in the development of an IMT enhanced night vision goggle for the U.S. Army's enhanced night vision goggle (ENVG). Finally, Northrop Grumman EOS is developing a NVG with the capability of producing optimized real-time image fusion from an image intensified sensor and uncooled long wavelength infrared (LWIR) sensor. This new technology allows for optimum imaging in battlefield obscured and laser polluted environment. These image fusion NVG development efforts have concentrated on both optical overlay image fusion and digital image fusion. This paper will compare and contrast these two types of image fusion technologies.
This paper presents the current status and summary of image intensified night vision system technologies using Northrop Grumman Electro-Optical Systems (NGEOS) advanced image intensifier (I2) tubes and associated NGEOS advanced I2 technologies. NGEOS advanced I2 technologies is divided into three fully proven and critical I2 subtechnologies: Unfilmed microchannel plate (MCP) based I2, Autogated power supply technologies, and 16mm halo free I2 technology. The initial discussion in this paper will center around the three major NGEOS advanced I2 subtechnologies and their respective night vision system performance benefits. Secondly, this paper will present and discuss the laboratory and field (ground and aerial) performance results from these various advanced night vision systems and technologies. Finally, this paper concludes with the extension and application of the previously noted advanced image intensifier technologies in digital imaging system applications such as image fusion systems combining image intensification and uncooled infrared sensors (SWIR/MWIR/LWIR).
Fusion of reflected/emitted radiation light sensors can provide significant advantages for target identification and detection. The two bands -- 0.6 - 0.9 or 1 - 2 micrometer reflected light and 8 - 12 micrometer emitted radiation -- offer the greatest contrast since those bands have the lowest correlation, hence the greatest amount of combined information for infrared imaging. Data from fused imaging systems is presented for optical overlay as well as digital pixel fusion. Advantages of the digital fusion process are discussed as well as the advantages of having both bands present for military operations. Finally perception tests results are presented that show how color can significantly enhance target detection. A factor of two reduction in minimum resolvable temperature difference is postulated from perception tests in the chromaticity plane. Although initial results do not yet validate this finding, it is expected with the right fusion algorithms and displays that this important result will be proven shortly.