Due to the suddenness and complexity of modern warfare, land-based weapon systems need to have precision strike capability on roads and railways. The vehicle navigation system is one of the most important equipments for the land-based weapon systems that have precision strick capability. There are inherent shortcomings for single source navigation systems to provide continuous and stable navigation information. To overcome the shortcomings, the multi-source positioning technology is developed. The All Source Positioning and Navigaiton (ASPN) program was proposed in 2010, which seeks to enable low cost, robust, and seamless navigation solutions for military to use on any operational platform and in any environment with or without GPS. The development trend of vehicle positioning technology was reviewed in this paper. The trend indicates that the positioning technology is developed from single source and multi-source to ASPN. The data fusion techniques based on multi-source and ASPN was analyzed in detail.
Due to its advantages on the cost, power and size, the study of the CMOS image sensor is considered as an important direction of the development of low-light-level image sensor. However, the sensitivity of current CMOS image sensor does not satisfy the low-light-level application requirements. This paper introduces several key techniques on how to improve the sensitivity of CMOS image sensors. We introduce a novel CMOS low-light-level image sensor based on Geiger mode avalanche photodiode (GM-APD) and digital TDI technology. Noise characteristics and complete signal-tonoise ratio(SNR) theoretical models are constructed for both sensors. A comparison of SNR performance of two image sensors is also done by numerical simulation in this paper. The results show that the novel CMOS low-light-level image sensor outperforms EMCCD at the very low light level.
In optical systems, the lens is the most important element, which has been widely used. Conventional lens takes advantage of its convex interface to change the phase along the light path, in order to focus light to a point in the focal plane. However, their spatial resolution is limited to approximately half of the working wavelength restricting the fine observation of tiny objects particular biological samples. Recently superlenses with high resolution focusing property beyond diffraction limit have been proposed without phase compensation resulting in the lack of ability of focus plane wave. We proposed metalens at mid-infrared region made of metamaterials slab and a phase compensation based on mono-layered concave film realizing subwavelength focusing ability (λ/3). The metamaterials slab consists of 200-layered metal -dielectric structure (doped GaN-Si) possessing hyperbolic regime. The curve shape and electromagnetic property of phase compensation mono-layered concave film is obtained through restrict theoretical computation which related to the parameters of the metamaterials slab. The proposed metalens can also be easily extended to three dimension for realistic application as conventional optical lens.
Planar metalens composed of V-shaped nano-antennas which can realize subwavelength focusing has been fabricated by Focused Ion Beam etching technology. The metalens was completely flat due to the phase manipulation deriving from the different V-shaped nano-antennas aligned in concentric circles. Comparing to conventional curved lens, the as-made metalens was flat and ultrathin (less than thickness of 100 nm) with light weight. Simulation results demonstrated that the focal length can be accurately controlled by changing the arrangement of the nano-antennas.