This paper presents an algorithm for target detection and tracking by fusion of multispectral imagery. In all spectral bands, we build a background model of the pixel intensities using a Gaussian mixture model, and pixels not belonging to the model are classified as foreground pixels. Foreground pixels from the spectral bands are weighted and summed into a single foreground map and filtered to give the fused foreground map. Foreground pixels are grouped into target candidates and associated with targets from a tracking database by matching features from the scale-invariant feature transform. The performance of our algorithm was evaluated with a synthetically generated data set of visible, near-infrared, midwave infrared, and long-wave infrared video sequences. With a fused combination of the spectral bands, the proposed algorithm lowers the false alarm rate while maintaining high detection rates. All 12 vehicles were tracked throughout the sequence, with one instance of a lost track that was later recovered.
Embedding polymer optical waveguides (WGs) into printed circuit boards (PCBs) for intra-board or board-to-board high
speed data communications requires polymer materials that are compatible and inert when exposed to common PCB
manufacturing processes. Ensuring both WG functionality after chemical exposure and maintaining PCB manufacturing
integrities within the production process is crucial for successful implementation. The PCB manufacturing flow is
analyzed to expose major requirements that would be required for the successful implementation of polymer materials
for embedded WG development. Chemical testing and analysis were performed on Dow Corning ® OE-4140 UV-Cured
Optical Elastomer Core and Dow Corning® OE-4141 UV-Cured Optical Elastomer Cladding which are designed for low
loss embedded optical WGs. Contamination testing was conducted to demonstrate polymer compatibility in both cured
and uncured form. Various PCB chemicals were treated with uncured polymer material and tested for effective
contamination. Fully polymerized multimode WGs were fabricated and exposed to PCB chemicals at temperatures and
durations comparable to PCB manufacturing conditions. Chemical analysis shows that the chosen polymer is compatible
and inert with most common PCB manufacturing processes.
Optical-electrical printed wiring boards were fabricated featuring mechanical transfer (MT)-compatible interconnections for out-of-plane optical signal routing with an average optical link loss of 10.7 dB. Commercially available components were integrated into an optical layer for out-of-plane optical routing, including light turning devices that feature spherical micro lens arrays, a total internal reflection mirror, and alignment slots compatible with standard MT connectors. The feasibility of the optical-electrical printed wiring board is discussed in detail to demonstrate its compatibility with common printed circuit board manufacturing processes. The optical-electrical printed wiring board prototypes survived thermal cycling (−40°C to 85°C) and humidity exposure (95% humidity) showing an overall degradation of <3 dB of optical performance. Operational failure (>18 dB ) occurred after environmental aging life testing at 110°C for 216 h.
With the ever-increasing demand for board-to-board optical data communications, the correlation between
waveguide surface end roughness and coupling losses must be thoroughly investigated. This study
measures end roughness of siloxane polymer optical waveguides in terms of optical coupling losses.
Siloxane Polymers from Dow Corning were used to fabricate 50 x 50 μm rectangular waveguides through
photolithographic processes. Edge roughness was controlled through various grades of fiber-optic polishing
films and then measured using interferometric microscopy (IFM). Controlled lab results are compared with
industrial polishing techniques that are consistent with mass-production methods. Electromagnetic
modeling revealed correlations between experimental and theoretical results.
Near the ground laser communication systems must operate in the presence strong atmospheric turbulence. To
model the performance of a laser communication system operating in the real world we have developed an outdoor
3.2 km, partially over water, turbulence measurement and monitoring communication link. The transmitter side
is equipped with the laser and the bank of 20 horizontally, in-line mounted light emitting diodes. The receiver
side consists of two channels used for wavefront sensor and point spread function measurements. The effects of
anisoplanatism on the point spread function and statistics of Fried parameter r0 are discussed in this article.
The outdoor 3.2km, partially over water, turbulence measurement and monitoring communication link has
being developed with the goal to statistically describe atmospheric turbulence using results derived from the
experimentally collected data. The system described in this paper has two transmitters and a receiver. The
transmitter side is equipped with the laser and the bank of 20 horizontally, in-line mounted LEDs. The receiver
side consists of the two-channel receiver allowing performing simultaneous wavefront sensor and point spread
function measurements.The data collected from both channels are used for the Fried parameter estimations. In
this paper we emphasize out attention on the data collection and analysis via point spread function channel only.
The results presented in this paper are based on the 6Tb of data collected through 40 days time interval, and
under various day and night atmospheric conditions.
So-called "free-space" laser communication systems working near the surface of the Earth must operate in the
presence of atmospheric turbulence. The effects of the atmospheric turbulence on the laser beam which are
relevant to optical communications are a broadening of the laser footprint, random jitter of the laser beam, and
high spatial frequency intensity fluctuations referred to as scintillation. The overall goal of our program is to
improve performance and extend the range of optical communications systems by exploring the use of adaptive
optics and channel coding. To better model the performance of a real system operating in the real world, we have
developed an outdoor turbulence-measurement and monitoring system. In this paper we describe an atmospheric
turbulence monitoring system for three kilometers, partially over water path. The laser transmitter operates
at 808 nm with a source power of 2mW. The receiver consists of relay optics, a Hartmann wave front sensor
(WFS), and a CCD camera. The WFS is used to monitor atmospheric turbulence-induced phase aberrations,
and the camera is used for both conventional imaging studies and measurements of anisoplanatic effects. In this
paper we describe this system and present some preliminary results obtained from the measurements.
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