The use of a wireless charging system for small, unmanned aircraft system applications is useful for both military and commercial consumers. An efficient way to keep the aircraft’s batteries charged without interrupting flight would be highly marketable. While the general concepts behind highly resonant wireless power transfer are discussed in a few publications, the details behind the system designs are not available even in academic journals, especially in relation to avionics. Combining a highly resonant charging system with a solar panel charging system can produce enough power to extend the flight time of a small, unmanned aircraft system without interruption. This paper provides an overview of a few of the wireless-charging technologies currently available and outlines a preliminary design for an aircraft-mounted battery charging system.
We describe a layer-1-based intrusion detection system for fiber-optic–based networks. Layer-1-based intrusion detection represents a significant elevation in security as it prohibits an adversary from obtaining information in the first place (no cryptanalysis is possible). We describe the experimental setup of the intrusion detection system, which is based on monitoring the behavior of certain attributes of light both in unperturbed and perturbed optical fiber links. The system was tested with optical fiber links of various lengths and types, under different environmental conditions, and under changes in fiber geometry similar to what is experienced during tapping activity. Comparison of the results for perturbed and unperturbed links has shown that the state of polarization is more sensitive to intrusion activity than the degree of polarization or power of the received light. The testing was conducted in a simulated telecommunication network environment that included both underground and aerial links. The links were monitored for intrusion activity. Attempts to tap the link were easily detected with no apparent degradation in the visual quality of the real-time surveillance video.
In this paper we describe a free-space optics (FSO) based mobile sensor network that is not subject to RF interference
common to wireless sensor networks. FSO-based mobile sensor networks can potentially be used in applications where
security of communication, including freedom from susceptibility to jamming, is important. The design of nodes
containing multiple transceivers each composed of an LED and an angle-diversity array of identical photo detectors is
discussed in this paper. Depending on the number of photodetectors in the array and the angular field of view of each
photo detector we may obtain an increase in the signal to noise ratio of the overall optical communication system.
Government funding for the security at shipping facilities and ports is limited so there is a need for low cost scalable
security systems. With over 20 million sea, truck, and rail containers entering the United States every year, these
facilities pose a large risk to security. Securing these facilities and monitoring the variety of traffic that enter and leave
is a major task. To accomplish this, the authors have developed and fielded a low cost fully distributed building block
approach to port security at the inland Port of Catoosa in Oklahoma. Based on prior work accomplished in the design
and fielding of an intelligent transportation system in the United States, functional building blocks, (e.g. Network,
Camera, Sensor, Display, and Operator Console blocks) can be assembled, mixed and matched, and scaled to provide a
comprehensive security system. The following functions are demonstrated and scaled through analysis and
demonstration: Barge tracking, credential checking, container inventory, vehicle tracking, and situational awareness.
The concept behind this research is "any operator on any console can control any device at any time."
With over 360 ports of entry and 20 million sea, truck, and rail containers entering the United States every year, port
facilities pose a large risk to security. Securing these ports and monitoring the variety of traffic that enter and leave is a
major task. To accomplish this, the authors propose a fully distributed building block approach to port security. Based
on prior work accomplished in the design and fielding of an intelligent transportation system in the United States,
building blocks can be assembled, mixed and matched, and scaled to provide a comprehensive security system. Network
blocks, surveillance blocks, sensor blocks, and display blocks will be developed and demonstrated in the lab, and at an
inland port. The following functions will be demonstrated and scaled through analysis and demonstration: Barge
tracking, credential checking, container inventory, vehicle tracking, and situational awareness. The concept behind this
research is "any operator on any console can control any device at any time."
We discuss the design of an acousto-optic cell based free space optical communication link where the data
beam is made secure through chaos encryption. Using external signal modulation of the diffracted light from
a hybrid acousto-optic cell chaos (or directly via incorporation in the sound-cell driver's bias voltage)
encryption of data is possible. We have shown numerically that decryption of the encoded data is possible by
using an identical acousto-optic system in the receiver.
Significant research efforts are underway to investigate the application of Free-Space Optics (FSO) for the provision
of high-bandwidth communications links between mobile platforms. The use of FSO between mobile platforms
introduces several interesting challenges in addition to those found in traditional fixed link FSO systems. In this
paper, some of the major hurdles facing fixed FSO communications that carry over into links between mobile
platforms are analyzed. These topics include: issues with alignment and tracking, an investigation into the weather
and its affect on the link, and a study of the feasibility of having uninterrupted communications links. Other topics
presented unique to mobile applications include: the security risks during link alignment, maintaining the link while
tracking and optical power and beam divergence variations that are introduced into the system. In this paper the
results from simulation work performed on some of these issues along with proposed solutions to the challenges are
This paper proposes an FSO-based mobile sensor network that is not subject to RF interference common to wireless
sensor networks. FSO-based mobile sensor networks can potentially be used in a battlefield where security of
communication, including freedom from susceptibility to enemy-induced jamming, is important. The paper discusses the
design of nodes containing multiple transceivers composed of LEDs and photo detectors. Results of initial experiments
are included. The work reported in this paper is part of an ongoing investigation on mobile FSO networks, including the
design of efficient protocols that can allow the mobile sensor nodes to function as a mesh network permitting
information exchange among nodes directly and, possibly, through an intermediate node.
A non-contact and low-cost nanomaterial based fiber-optic sensor is developed for measuring large values of electric
currents. The magnetic field, generated by the electric current, changes the refractive index of a liquid in which
nanomaterial particles are suspended. The change of refractive index is converted to a change in the intensity of light
transmitted in an evanescent field based fiber optic sensor. The change in the intensity is proportional to the magnitude
of the electric current and thus the current can be measured by measuring the resultant change in the intensity of light.
With the ever present threat to commerce, both politically and economically, technological innovations provide a means to secure the transportation infrastructure that will allow efficient and uninterrupted freight-flow operations for trade. Currently, freight coming into United States ports is "spot checked" upon arrival and stored in a container yard while awaiting the next mode of transportation. For the most part, only fences and security patrols protect these container storage yards. To augment these measures, the authors propose the use of aerial surveillance vehicles equipped with video cameras and wireless video downlinks to provide a birds-eye view of port facilities to security control centers and security patrols on the ground. The initial investigation described in this paper demonstrates the use of unmanned aerial surveillance vehicles as a viable method for providing video surveillance of container storage yards. This research provides the foundation for a follow-on project to use autonomous aerial surveillance vehicles coordinated with autonomous ground surveillance vehicles for enhanced port security applications.
Free-space optical (FSO) communications links are envisioned as a viable option for the provision of temporary high-bandwidth
communication links between moving platforms, especially for deployment in battlefield situations. For
successful deployment in such real-time environments, fast and accurate alignment and tracking of the FSO equipment is
essential. In this paper, a two-wavelength diversity scheme using 1.55 μm and 10 μm is investigated in conjunction with
a previously described tracking algorithm to maintain line-of-sight connectivity battlefield scenarios. An analytical
model of a mobile FSO communications link is described. Following the analytical model, simulation results are
presented for an FSO link between an unmanned aerial surveillance vehicle, the Global Hawk, with a mobile ground
vehicle, an M1 Abrams Main Battle Tank. The scenario is analyzed under varying weather conditions to verify
continuous connectivity is available through the tracking algorithm. Simulation results are generated to describe the
performance of the tracking algorithm with respect to both received optical power levels and variations in beam
divergence. Advances to any proposed tracking algorithm due to these power and divergence variations are described
for future tracking algorithm development.
Free Space Optics (FSO) technology is currently in use to solve the last-mile problem in telecommunication systems by
offering higher bandwidth than wired or wireless connections when optical fiber is not available. Incorporating mobility
into FSO technology can contribute to growth in its utility. Tracking and alignment are two big challenges for mobile
FSO communications. In this paper, we present a theoretical approach for mobile FSO networks between Unmanned
Aerial Vehicles (UAVs), manned aerial vehicles, and ground vehicles. We introduce tracking algorithms for achieving
Line of Sight (LOS) connectivity and present analytical results. Two scenarios are studied in this paper: 1 - An
unmanned aerial surveillance vehicle, the Global Hawk, with a stationary ground vehicle, an M1 Abrams Main Battle
Tank, and 2 - a manned aerial surveillance vehicle, the E-3A Airborne Warning and Control System (AWACS), with an
unmanned combat aerial vehicle, the Joint Unmanned Combat Air System (J-UCAS). After initial vehicle locations
have been coordinated, the tracking algorithm will steer the gimbals to maintain connectivity between the two vehicles
and allow high-speed communications to occur. Using this algorithm, data, voice, and video can be sent via the FSO
connection from one vehicle to the other vehicle.