Spelling suggestions: "subject:"over then horizon."" "subject:"over them horizon.""
1 |
Extensions to the probabilistic multi-hypothesis tracker for improved data association / Samuel J. Davey/Davey, Samuel Jarrod January 2003 (has links)
"September 2003" / Bibliography: leaves 209-216. / xxvi, 216 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis has introduced a number of enhancements to the PMHT algorithm, motivated by the Over the Horizon Radar tracking problem. The two primary enhancements are the incorporation of classification information, and the introduction of a discrete state model for the assignment prior probability. The modified PMHT algorithms achieved through these enhancements are referred to as PMHT-c and PMHT-y respectively. / Thesis (Ph.D.)--University of Adelaide, School of Electrical and Electronic Engineering, 2003
|
2 |
Over-the-horizon radar array calibrationSolomon, Ishan Samjeva Daniel. January 1998 (has links) (PDF)
Includes bibliographical references. Due to the rapid deployment of modern over-the-horizon radars, antenna/sensor position errors may be present and, since the antennas have a simple and cost-effective design, mutual coupling may also be present. These imperfections, which can degrade radar performance, form the basis of the investigation. Also calibrates the receiving array of the Jindalee over-the-horizon radar (located in Central Australia) using echoes from meteor trails.
|
3 |
Over-the-horizon radar array calibration /Solomon, Ishan Samjeva Daniel. January 1998 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, 1998. / Includes bibliographical references.
|
4 |
Over-the-horizon radar array calibration / by Ishan Samjeva Daniel Solomon.Solomon, Ishan Samjeva Daniel January 1998 (has links)
Includes bibliographical references (p. 207-232) / xxii, 232 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Due to the rapid deployment of modern over-the-horizon radars, antenna/sensor position errors may be present and, since the antennas have a simple and cost-effective design, mutual coupling may also be present. These imperfections, which can degrade radar performance, form the basis of the investigation. Also calibrates the receiving array of the Jindalee over-the-horizon radar (located in Central Australia) using echoes from meteor trails. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1998
|
5 |
Over-the-horizon radar array calibration / by Ishan Samjeva Daniel Solomon.Solomon, Ishan Samjeva Daniel January 1998 (has links)
Includes bibliographical references (p. 207-232) / xxii, 232 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Due to the rapid deployment of modern over-the-horizon radars, antenna/sensor position errors may be present and, since the antennas have a simple and cost-effective design, mutual coupling may also be present. These imperfections, which can degrade radar performance, form the basis of the investigation. Also calibrates the receiving array of the Jindalee over-the-horizon radar (located in Central Australia) using echoes from meteor trails. / Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1998
|
6 |
Shallow Water Training RangeReid, Robert 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / During the cold war, undersea warfare (USW) was perceived as a large-area, deep-water operation. The need for USW has recently shifted to the shallow water, littoral environment. Consequently, US naval forces must train to operate in these littoral environments where regional conflicts are most likely to occur. In light of these requirements the Shallow Water Training Range (SWTR) has been initiated. Telemetry is used in the following areas of SWTR: fiber optic, microwave, RF and underwater. Only phase 1 of 8 phases of the program is executing therefore SWTR is a good opportunity for telemetry industry involvement.
|
7 |
EYE IN THE SKY: AIRSHIP SURVEILLANCESullivan, Arthur, Turner, William C. 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The first airship was invented and designed in 1852 by Henri Giffard, a French
engineer. Airships were used by both the Allied and German military for surveillance
and bomb dropping in WWI. There was a steady increase in airship use up until the
Hindenburg exploded while docking in 1937 at Lakehurst, New Jersey. This tragedy
almost ended the use of airships. Significant use of airships next occurred during
WWII for submarine surveillance and depth charging. Airships for advertising,
surveillance, and command control came of age in the late 1980s and early 1990s.
Airships can be fitted with several telemetry options or instrumented with sensor
systems for surveillance purposes. The telemetry or sensor data can be relayed, real-time,
to a remote station as much as 150 km from the airship either encrypted or plain
when cruising at 3000 feet altitude. Small vehicles (3 meters long) can be detected at
50 km using radar; 12 km using FLIRs; and, depending on weather conditions and
real-time imaging processing, up to 20 km using video cameras. Cooperating airborne
targets can be tracked out to 150 km.
The major advantages of the airship over conventional aircraft are:
• ENDURANCE Up to 20 hours without refueling.
• LOW OPERATING COST Less than the cost of a helicopter.
• SHOCK-FREE ENVIRONMENT Allows commercial electric equipment usage.
• VIBRATION-FREE ENVIRONMENT Yields personnel comfort and endurance.
• SAFETY Safer than any aircraft, automobile, or bicycle.
|
8 |
Flight Safety System for Unmanned Air VehiclePérez-Falcón, Tony, Kolar, Ray 10 1900 (has links)
International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / A Flight Safety System (RAFS) for multiple, reliable Unmanned Air Vehicles (UAV’s) capable of
flying Over-the-Horizon (OTH) and outside test range airspace. In addition to the flight safety
application, the described full-duplex data link is suitable as a backup command and control link for
UAV’s, and for sensor control & data exfiltration.
The IRIDIUM satellite system was selected to provide the communications link and because of its
global coverage and requisite data throughputs.
A Risk Reduction activity ensued to quantify IRIDIUM performance. Hardware and software was
developed to demonstrate the feasibility of using IRIDIUM in a flight safety scenario.
|
9 |
FLIGHT SAFETY SYSTEM FOR UNMANNED AIRBORNE VEHICLES (UAVs)Pérez-Falcón, Tony, Kolar, Ray 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper presents a Flight Safety System (FSS) for multiple, reliable Unmanned Air Vehicles (UAV’s) capable of flying Over-the-Horizon (OTH) and outside test range airspace. Expanded uses beyond flight safety, such as UAV Air Traffic Control, are considered also. This system satisfies the operational requirement for a Hazard Control Communication Channel as well as providing a reverse communications channel to provide Safety Critical Information to the Range Safety Officer (RSO). Upon examining 60 communications candidates, IRIDIUM accessed through a Data Distribution Network (DDN), with ARINC being a potential service provider, is recommended.
|
10 |
TIME-FREQUENCY ANALYSIS TECHNIQUES FOR NON-STATIONARY SIGNALS USING SPARSITYAMIN, VAISHALI, 0000-0003-0873-3981 January 2022 (has links)
Non-stationary signals, particularly frequency modulated (FM) signals which arecharacterized by their time-varying instantaneous frequencies (IFs), are fundamental
to radar, sonar, radio astronomy, biomedical applications, image processing, speech
processing, and wireless communications. Time-frequency (TF) analyses of such signals
provide two-dimensional mapping of time-domain signals, and thus are regarded
as the most preferred technique for detection, parameter estimation, analysis and
utilization of such signals.
In practice, these signals are often received with compressed measurements as a
result of either missing samples, irregular samplings, or intentional under-sampling of
the signals. These compressed measurements induce undesired noise-like artifacts in
the TF representations (TFRs) of such signals. Compared to random missing data,
burst missing samples present a more realistic, yet a more challenging, scenario for
signal detection and parameter estimation through robust TFRs. In this dissertation,
we investigated the effects of burst missing samples on different joint-variable domain
representations in detail.
Conventional TFRs are not designed to deal with such compressed observations.
On the other hand, sparsity of such non-stationary signals in the TF domain facilitates
utilization of sparse reconstruction-based methods. The limitations of conventional
TF approaches and the sparsity of non-stationary signals in TF domain motivated us
to develop effective TF analysis techniques that enable improved IF estimation of such
signals with high resolution, mitigate undesired effects of cross terms and artifacts
and achieve highly concentrated robust TFRs, which is the goal of this dissertation.
In this dissertation, we developed several TF analysis techniques that achieved
the aforementioned objectives. The developed methods are mainly classified into two
three broad categories: iterative missing data recovery, adaptive local filtering based TF approach, and signal stationarization-based approaches. In the first category,
we recovered the missing data in the instantaneous auto-correlation function (IAF)
domain in conjunction with signal-adaptive TF kernels that are adopted to mitigate
undesired cross-terms and preserve desired auto-terms. In these approaches, we took
advantage of the fact that such non-stationary signals become stationary in the IAF
domain at each time instant. In the second category, we developed a novel adaptive
local filtering-based TF approach that involves local peak detection and filtering of
TFRs within a window of a specified length at each time instant. The threshold for
each local TF segment is adapted based on the local maximum values of the signal
within that segment. This approach offers low-complexity, and is particularly
useful for multi-component signals with distinct amplitude levels. Finally, we developed
knowledge-based TFRs based on signal stationarization and demonstrated
the effectiveness of the proposed TF techniques in high-resolution Doppler analysis
of multipath over-the-horizon radar (OTHR) signals. This is an effective technique
that enables improved target parameter estimation in OTHR operations. However,
due to high proximity of these Doppler signatures in TF domain, their separation
poses a challenging problem. By utilizing signal self-stationarization and ensuring IF
continuity, the developed approaches show excellent performance to handle multiple
signal components with variations in their amplitude levels. / Electrical and Computer Engineering
|
Page generated in 0.0731 seconds