PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.
This PDF file contains the front matter associated with SPIE
Proceedings Volume 7833, including the Title Page, Copyright
information, Table of Contents, and the Conference Committee listing.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Automatic Identification System (AIS) is an unattended vessel reporting system developed for collision avoidance.
Shipboard AIS equipment automatically broadcasts vessel positional data at regular intervals. The real-time position and
identity data from a vessel is received by other vessels in the area thereby assisting with local navigation. As well, AIS
broadcasts are beneficial to those concerned with coastal and harbour security. Land-based AIS receiving stations can
also collect the AIS broadcasts. However, reception at the land station is dependent upon the ship's position relative to
the receiving station. For AIS to be used as a trusted surveillance system, the characteristics of the AIS coverage area in
the vicinity of the station (or stations) should be understood. This paper presents some results of a method being
investigated at DRDC Atlantic (Canada) to map the AIS coverage characteristics of a dynamic AIS reception network.
The method is shown to clearly distinguish AIS reception edges from those edges caused by vessel traffic patterns. The
method can also be used to identify temporal changes in the coverage area, an important characteristic for local maritime
security surveillance activities. Future research using the coverage estimate technique is also proposed to support
surveillance activities.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
There are very good automatic detection algorithms available to be used in an Automatic Target Recognition
applications. However they need lots of data for training the detector for the specific use, e.g., performing an inventory
of wild animals. Ongoing work use thermally correct infrared models of animals for training the detector because
collecting real images from these wild animals is too expensive if even possible. This paper describes the process of
designing a good IR model of the animals, and the validation process of the thermal model. Several animals are modeled
using RadThermIR to be used for training detection algorithms. Animal models are based on commercially available
CAD models and are initiated by temperature values from real IR measurements in several different weather conditions.
The modeling extends the available set of training images by introducing different weather conditions and different poses
of the animal. Fat and fur thickness of the animal is modeled with respect to climate and weather.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
In this work we focus on the task to localize and track multiple non-cooperative targets by a passive antenna
array and an optical sensor. Both sensor systems are mounted on a UAV and obtain bearing measurements
from the targets, where the number of targets is unknown. To solve the localization and tracking problem, the
imprecise but unique bearing data collected from the antenna array has to be correlated with the precise but
ambiguous bearing data gained from the optical system. We perform this by a Monte Carlo realization of a
multi-sensor probability hypothesis density (PHD) filter.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
We describe the fabrication of a turbocharged, microelectromechanical system (MEMS) turbine. The turbine will be
part of a standalone power unit and includes extra layers to connect the turbine to a generator. The project goal is to
demonstrate the successful combination of several features, namely: silicon fusion bonding (SFB), a micro turbocharger
[2], two rotors, mechanical alignment between two wafers [1], and the use of only one 5" silicon wafer. The dimension
of the actual turbine casing will be 14mm. The turbine rotor will have a diameter of 8mm. Given these dimensions,
MEMS processes are an adequate way to fabricate the device, but it will be necessary to stack up seven different layers
to build the turbine, as it is not possible to construct it out of one thick wafer. SFB will be used for bonding because it
permits the great precision necessary for high quality alignment. Yet a more precise alignment will be necessary between
the layers that contain the turbine rotor, to decrease imbalance and guarantee operation at a very high rpm. To achieve
these tight tolerances, a mechanical alignment feature announced by Liudi Jiang [1] is used. The alignment accuracy is
expected to be around 200nm. Despite the fact that the turbine consists of multiple layers, it will be fabricated on only
one silicon-on-insulator (SOI) wafer. As a result, all layers are exposed to the same process flow. The fabrication process
includes MEMS technology as photolithography, nine deep reactive ion etching (DRIE) steps, and six SFB operations. A
total of 14 masks are necessary for the fabrication.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
A common miniature environment-insensitive navigation module which not only can provide the accurate
position through different environment but also can easily be configured to adapt to the different type of
unmanned vehicles is proposed in this paper. The module prototype is composed of a integrated MEMS
inertial navigation unit using MEMS accelerometers and gyroscopes, a hard aluminum module structure
with rubber isolator, a series of sensor interface of magnetometer, embedded GPS receiver, infrared sensor,
vision camera, radio frequency communication etc and a FPGA based central control and navigation
calculation circuit. The fabricated MEMS accelerometers and gyroscopes can resist high-g shock and have
temperature drift compensation. The structure of the module uses hard aluminum with finite element
analysis to find the appropriate position for sensors. All sensors without antenna are packaged in the
structure with moisture, heat isolation and rubber isolator. The navigation computation scheme use the
status of connected sensors to choose appropriate algorithm function to compute the navigation output.
FPGA is used to be the main control and process unit of this module. Algorithms are embedded in the
FPGA using the DSP core. The multiply interfaces to other sensor are implemented using the flexible
configuration of the FPGA and peripheral. The conclusions are reached at last.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper presents a new linear inertial acceleration switch which senses inertial
acceleration and gives a signal of switchpoint. It is an entire mechanical device has two particular
characters: a simple structure and an environmental interference-free capability. The structure and
work principle of the switch is introduced, then the design process to the spring is analyzed and
simulated, and finally the rationality of this acceleration switch's design is given according to the
sample's testing data.
In this acceleration switch, the elastic component is a leaf spring, and the mass component
is a standard steel ball. The spring and the ball are separated instead of rigidly connected, which
make the whole structure is simple. When the switch is on the work direction the ball and the
spring are interact, and the spring is on work; when the switch isn't on the work direction, the ball
and the spring are separated; environmental external force is on the mass instead of on the spring.
The spring is insusceptible on this condition. This particularity determines that the switch is highly
environmental interference-free, and doesn't easily affected by environmental influence.
Some parameters of the inertial switch are given as followings: (1) Overall dimension of the
inertial switch is about 28mm×12mm×12mm; (2) systemic precision of the inertial switch is 1.5%;
(3) the inertial switch can endure 0.2g2/Hz stochastic vibration. It is suggested that this inertial
switch can be applied in high consequence system.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
A novel range detection technique combines optical pulse modulation patterns with signal cross-correlation to produce
an accurate range estimate from low power signals. The cross-correlation peak is analyzed by a post-processing
algorithm such that the phase delay is proportional to the range to target. This technique produces a stable range
estimate from noisy signals. The advantage is higher accuracy obtained with relatively low optical power transmitted.
The technique is useful for low cost, low power and low mass sensors suitable for tactical use. The signal coding
technique allows applications including IFF and battlefield identification systems.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper describes a prototype demonstration of a high bandwidth data link between the fuselage of an aircraft
and a helmet mounted display. A single data receiver, powered by battery and equipped with a light-collecting
optical antenna to increase optical gain, is worn on the body of the pilot, with a fast-modulated laser transmitter
mounted in the pilot's seat area. The combination covered the expected range of body movement that a pilot
typically undergoes during a flight. Uncompressed, ~140Mbps video data is streamed over the free-space link
to a BAE Systems helmet mounted display (Q-Sight™) worn by the pilot.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
We describe the development of flexi-circuit addressed, high resolution small aperture Bimorph Deformable Mirror
(BDM) suitable for a satellite to ground optical communications system. In the first phase, the base of an existing BDM
was modified to enable integration onto a commercially available tip-tilt stage. Evaluation demonstrated that there was
no reduction in performance as a result of the integration. In the current phase, a 100 element BDM with a 10mm optical
aperture suitable for integration onto a bespoke tip-tilt platform has been designed and assembled. The results of initial
tests are presented.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Keynote Session 1: Unmanned Systems Technologies I
This paper presents an overview of a human-robotic system under development at Cornell which is capable of
mapping an unknown environment, as well as discovering, tracking, and neutralizing several static and dynamic
objects of interest. In addition, the robots can coordinate their individual tasks with one another without overly
burdening a human operator. The testbed utilizes the Segway RMP platform, with lidar, vision, IMU and GPS
sensors. The software draws from autonomous systems research, specifically in the areas of pose estimation,
target detection and tracking, motion and behavioral planning, and human robot interaction. This paper also
details experimental scenarios of mapping, tracking, and neutralization presented by way of pictures, data, and
movies.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Dead Reckoning (DR) is the process of estimating a robot's current position based upon a previously determined
position, and advancing that position based upon known speed and direction over time. It is therefore a simple way for an
autonomous mobile robot to navigation within a known environment such as a building where measurements have been
taken and a predetermined route planned based upon which doors (or areas) the robot would have enough force to enter.
Discussed here is the design of a DR navigation system in Altera's DSP Builder graphical design process. The wheel
circumference to the step size of stepper motor used to drive the robot are related and so this ratio can be easily changed
to easily accommodate changes to the physical design of a robot with minimal changes to the software. The robot
calculates its position in relation to the DR map by means of the number of revolutions of the wheels via odometry, in
this situation there is no assumed wheel slippage that would induce an accumulative error in the system overtime. The
navigation works by using a series of counters, each corresponding to a measurement taken from the environment, and
are controlled by a master counter to trigger the correct counter at the appropriate time given the position of robot in the
DR map. Each counter has extra safeguards built into them on their enables and outputs to ensure they only count at the
correct time and to avoid clashes within the system. The accuracy of the navigation is discussed after the virtual route is
plotted in MATLAB as a visual record in addition to how feedback loops, identification of known objects (such as fire
safety doors that it would navigate through), and visual object avoidance could later be added to augment the system.
The advantages of such a system are that it has the potential to upload different DR maps so that the end robot for can be
used in new environments easily.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
This paper explores representations for capturing the anticipation of other objects by an autonomous robot in
an urban environment. Predictive Gaussian mixture models are proposed due to their ability to probabilistically
capture continuous and discrete obstacle behavior; the predictive system uses the probabilistic output of a
tracking system (current obstacle location), and map (with lanes and intersections). The probabilistic tracking
and anticipated motion are integrated into an optimized path planner. This paper explores various levels of
model abstraction to understand how complex these predictive models must be in order to create a more robust
path planning algorithm.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Unattended ground sensors (UGS) provide the capability to inexpensively secure remote borders and other
areas of interest. However, the presence of normal animal activity can often trigger a false alarm.
Accurately detecting humans and distinguishing them from natural fauna is an important issue in security
applications to reduce false alarm rates and improve the probability of detection. In particular, it is
important to detect and classify people who are moving in remote locations and transmit back detections
and analysis over extended periods at a low cost and with minimal maintenance. We developed and
demonstrate a compact radar technology that is scalable to a variety of ultra-lightweight and low-power
platforms for wide area persistent surveillance as an unattended, unmanned, and man-portable ground
sensor. The radar uses micro-Doppler processing to characterize the tracks of moving targets and to then
eliminate unimportant detections due to animals as well as characterize the activity of human detections.
False alarms from sensors are a major liability that hinders widespread use. Incorporating rudimentary
intelligence into sensors can reduce false alarms but can also result in a reduced probability of detection.
Allowing an initial classification that can be updated with new observations and tracked over time provides
a more robust framework for false alarm reduction at the cost of additional sensor observations. This paper
explores these tradeoffs with a small radar sensor for border security.
Multiple measurements were done to try to characterize the micro-Doppler of human versus animal and
vehicular motion across a range of activities. Measurements were taken at the multiple sites with realistic
but low levels of clutter. Animals move with a quadrupedal motion, which can be distinguished from the
bipedal human motion. The micro-Doppler of a vehicle with rotating parts is also shown, along with
ground truth images. Comparisons show large variations for different types of motion by the same type of
animal.
This paper presents the system and data on humans, vehicles, and animals at multiple angles and directions
of motion, demonstrates the signal processing approach that makes the targets visually recognizable,
verifies that the UGS radar has enough micro-Doppler capability to distinguish between humans, vehicles,
and animals, and analyzes the probability of correct classification.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Stereo vision is a situation where an imaging system has two or more cameras in order to make it more robust
by mimicking the human vision system. By using two inputs, knowledge of their own relative geometry can
be exploited to derive depth information from the two views they receive. 3D co-ordinates of an object in an
observed scene can be computed from the intersection of the two sets of rays. Presented here is the development
of a stereo vision system to focus on an object at the centre of a baseline between two cameras at varying
distances. This has been developed primarily for use on a Field Programmable Gate Array (FPGA) but an
adaptation of this developed methodology is also presented for use with a PUMA 560 Robotic Manipulator with
a single camera attachment. The two main vision systems considered here are a fixed baseline with an object
moving at varying distances from this baseline, and a system with a fixed distance and a varying baseline. These
two differing situations provide enough data so that the co-efficient variables that determine the system operation
can be calibrated automatically with only the baseline value needing to be entered, the system performs all the
required calculations for the user for use with a baseline of any distance. The limits of system with regards to
the focusing accuracy obtained are also presented along with how the PUMA 560 controls its joints for the stereo
vision and how it moves from one position to another to attend stereo vision compared to the two camera system
for the FPGA. The benefits of such a system for range finding in mobile robotics are discussed and how this
approach is more advantageous when compared against laser range finders or echolocation using ultrasonics.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The paper presents the concept of optoelectronic devices for human protection in rescue activity.
The system consists of an ground robots with predicted sensor. The multisensor construction of the system
ensures significant improvement of security of using on-situ like chemical or explosive sensors. The article
show a various scenario of use for individual sensor in system PROTEUS.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
State-of-the-art Inertial Navigation Systems (INS) based on Micro-Electro-Mechanical Systems (MEMS) have
a lack of precision especially in GPS denied environments like urban canyons or in pure indoor missions. The
proposed Optical Navigation System (ONS) provides bias free ego-motion estimates using triple redundant sensor
information. In combination with a model based state prediction our system is able to estimate velocity, position
and attitude of an arbitrary aircraft. Simulating a high performance flow-field estimator the algorithm can
compete with conventional low-cost INS. By using measured velocities instead of accelerations the system states
drift behavior is not as distinctive as for an INS.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Active & Passive Imagers, Image Sensing and Processing
To allow Unmanned Aircraft Systems (UAS) accessing National Airspace System (NAS) "Equivalent levels of safety"
to the ones of human vision must be guaranteed. Therefore, an appropriate "Sense and Avoid" technology must be
developed that is capable of detecting, tracking, and avoiding obstacles. The Department of Aerospace Engineering at
University of Naples has been involved in a project funded by the Italian Aerospace Research Centre (CIRA) for the
realization of a prototypical "Obstacle Detection & Identification" (ODID) System. It is installed onboard a Very Light
Aircraft (VLA) and it is characterized by a hierarchical sensor configuration in which the radar is the main sensor while
EO cameras are the auxiliary ones in order to increase accuracy and data rate so that anti-collision requirements are
fulfilled.
This paper focuses on the Image Processing algorithm for the panchromatic camera. Among the several techniques listed
in literature the edge detection - labeling one resulted as the best compromise in terms of computational load, detection
range, false alarm rate, miss detection rate and adaptability at different background luminosity conditions. Moreover it
has been customized in order to allow for reliable operation in a wide range of flight and luminance configurations and it
has been tested and run on a sequence of real images taken during flight tests. At the end, a table that summarizes those
results is presented. Indeed, the output tracking measurements accuracy increases by an order of magnitude with respect
to standalone radar one.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Military fighter pilots have to make suitable decisions fast in an environment where continuously increasing flows
of information from sensors, team members and databases are provided. Not only do the huge amounts of data
aggravate the pilots' decision making process: time-pressure, presence of uncertain data and high workload are
factors that can worsen the performance of pilot decision making. In this paper, initial ideas of how to support
the pilots accomplishing their tasks are presented. Results from interviews with two fighter pilots are described
as well as a discussion about how these results can guide the design of a military fighter pilot decision support
system, with focus on team cooperation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
The imbalanced learning problem (learning from imbalanced data) presents a significant new challenge to the pattern
recognition and machine learning society because in most instances real-world data is imbalanced. When
considering military applications, the imbalanced learning problem becomes much more critical because such
skewed distributions normally carry the most interesting and critical information. This critical information is
necessary to support the decision-making process in battlefield scenarios, such as anomaly or intrusion detection.
The fundamental issue with imbalanced learning is the ability of imbalanced data to compromise the
performance of standard learning algorithms, which assume balanced class distributions or equal misclassification
penalty costs. Therefore, when presented with complex imbalanced data sets these algorithms may not
be able to properly represent the distributive characteristics of the data. In this paper we present an empirical
study of several popular imbalanced learning algorithms on an army relevant data set. Specifically we will
conduct various experiments with SMOTE (Synthetic Minority Over-Sampling Technique), ADASYN (Adaptive
Synthetic Sampling), SMOTEBoost (Synthetic Minority Over-Sampling in Boosting), and AdaCost (Misclassification
Cost-Sensitive Boosting method) schemes. Detailed experimental settings and simulation results are
presented in this work, and a brief discussion of future research opportunities/challenges is also presented.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
MWIR photon detector in the mid-infrared wavelength (2-5 μm) range is developed using crystalline silicon carbide
substrates. SiC, which is a wideband gap semiconductor, is laser-doped to create a dopant energy level corresponding to
a quantum of energy for the required operating wavelength of the detector. The photons of the objects in the field of
view excite the electrons of the detector, leading to changes in the refractive index. This change in the optical property of
the detector can be measured remotely with a laser beam, such as a He-Ne laser beam of wavelength 632.8 nm, which
makes it a wireless detector. While many IR detectors require cryogenic cooling (77 K) to suppress thermal generationrecombination
processes in order to operate with good detectivity, the SiC-based detector can operate at room
temperature with excellent performance. An n-type 4H-SiC substrate has been doped with Ga by a laser doping
technique to create a detector element for the MWIR wavelength of 4.21 μm corresponding to the photon energy 0.30
eV. The dopant energy level is confirmed by optical absorption measurements. The change in the refractive index is
studied as a function of absorbed irradiance on the detector. The experimental result shows that the Ga-doped 4H-SiC
sample can be used for MWIR detectors.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Morphological Scene Change Detection (MSCD) is a process typically tasked at detecting relevant changes in a guarded
environment for security applications. This can be implemented on a Field Programmable Gate Array (FPGA) by a
combination of binary differences based around exclusive-OR (XOR) gates, mathematical morphology and a crucial
threshold setting. The additional ability to set up the system in virtually any location due to the FPGA makes it ideal for
insertion into an autonomous mobile robot for patrol duties. However, security is not the only potential of this robust
algorithm. This paper details how such a system can be used for the detection of leaks in piping for use in the process
and chemical industries and could be deployed as stated in the above manner. The test substance in this work was water,
which was pumped either as a liquid or as low pressure steam through a simple pipe configuration with holes at set
points to simulate the leaks. These holes were situated randomly at either the center of a pipe (in order to simulate an
impact to it) or at a joint or corner (to simulate a failed weld). Imagery of the resultant leaks, which were visualised as
drips or the accumulation of steam, which where analysed using MATLAB to determine their pixel volume in order to
calibrate the trigger for the MSCD. The triggering mechanism is adaptive to make it possible in theory for the type of
leak to be determined by the number of pixels in the threshold of the image and a numerical output signal to state which
of the leak situations is being observed. The system was designed using the DSP Builder package from Altera so that its
graphical nature is easily comprehensible to the non-embedded system designer. Furthermore, all the data from the DSP
Builder simulation underwent verification against MATLAB comparisons using the image processing toolbox in order to
validate the results.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Fiber optical interferometers belong to highly sensitive equipments that are able to measure slight changes like distortion
of shape, temperature and electric field variation and etc. Their great advantage is that they are insensitive on ageing
component, from which they are composed of. It is in virtue of herewith, that there are evaluated no changes in optical
signal intensity but number interference fringes. To monitor the movement of persons, eventually to analyze the changes
in state of motion we developed method based on analysis the dynamic changes in interferometric pattern. We have used
Mach- Zehnder interferometer with conventional SM fibers excited with the DFB laser at wavelength of 1550 nm. It was
terminated with optical receiver containing InGaAs PIN photodiode. Its output was brought into measuring card module
that performs on FFT of the received interferometer signal. The signal rises with the composition of two waves passing
through single interferometer arm. The optical fiber SMF 28e in one arm is referential; the second one is positioned on
measuring slab at dimensions of 1x2m. A movement of persons over the slab was monitored, signal processed with FFT
and frequency spectra were evaluated. They rose owing to dynamic changes of interferometric pattern. The results reflect
that the individual subjects passing through slab embody characteristic frequency spectra, which are individual for
particular persons. The scope of measuring frequencies proceeded from zero to 10 KHz. It was also displayed in
experiments that the experimental subjects, who walked around the slab and at the same time they have had changed
their state of motion (knee joint fixation), embodied characteristic changes in their frequency spectra. At experiments the
stability of interferometric patterns was evaluated as from time aspects, so from the view of repeated identical
experiments. Two kinds of balls (tennis and ping-pong) were used to plot the repeatability measurements and the gained
spectra at repeated drops of balls were compared. Those stroked upon the same place and from the same elevation and
dispersion of the obtained frequency spectra was evaluated. These experiments were performed on the series of 20
repeated drops from highs of 0,5 and 1m. The evaluation of experiments displayed that the dispersion of measured
values is lower than 4%.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Effective situation awareness is a critical element for decision support in a wide range of military and para-military
operational surveillance scenarios. Effective situation awareness in a surveillance scenario can greatly increase
operational effectiveness, by improving the quality and timeliness of decisions. In this paper we outline a three level
integrated design approach to promote situation awareness. Our approach allows deployed wireless sensor nodes to
efficiently self-organise into dynamic clusters, based on a current common perceived threat situation (context). Firstly
our distributed predator aware situation assessment system (PORTENT) models, detects and presents, in terms of quality
of information (QoI), potential situations occurring within an uncertain environment. Secondly, we utilise a Bayesian
belief network to understand the significance associated with the potential situation. Finally in order to obtain a better
shared awareness we have developed a "context aware" service protocol that supports group formation and efficient
management of sensor network assets. By combining this three level approach, we present our VIGILANT "situation
aware" QoI interest group system. Extensive simulations have been undertaken to verify the VIGILANT concept, to
demonstrate the effectiveness of our approach, in improving performance for network management efficiency, through
utilisation of a shared "context" service provision time and QoI surveillance presentation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
Free-space optics (FSO) holds the potential for high bandwidth communication, but atmospheric conditions can
significantly affect the capability of this type of communication system to transfer information consistently and operate
effectively. The effects of atmosphere on FSO communication and consequent optimal wavelength range for
transmission are investigated through MODTRAN-based modeling of 1.55 μm transmission for multiple elevation
angles in atmospheric weather conditions including clear maritime, desert extinction, and various levels of rain and fog,
to simulate surface-to-surface and surface-to-air FSO communication networks. Furthermore, atmospheric, free-space,
and scintillation losses are analyzed for optical path lengths of 2 km to determine minimum transmit power required for
successful data reception. In addition, FSO transmitter and receiver circuits were designed to optically relay analog
video signals and their operation verified at path distances of up to 130 m. Using advanced laser sources to provide
illumination at infrared wavelengths, particularly around the eye-safe 1.55 μm wavelength, it should be possible to
overcome many transmission limitations associated with atmospheric conditions such as adverse weather and turbulence.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.