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Predicting Topographic and Bathymetric Measurement performance for Low-SNR Airborne Lidar

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 2009年第7期47卷 2298-2315页

作者： Cossio, Tristan Slatton, K. Clint Carter, William Shrestha, Kris Harding, David Univ Florida Dept Elect & Comp Engn Adapt Signal Proc Lab Gainesville FL 32611 USA Univ Florida Natl Ctr Airborne Laser Mapping Dept Civil & Coastal Engn Gainesville FL 32611 USA NASA Goddard Space Flight Ctr Planetary Geodynam Lab Sci & Explorat Directorate Greenbelt MD 20771 USA

Government and commercial airborne light detection and ranging (lidar) systems have enabled extensive measurements of the Earth's surface and land cover over the past decade. There is much interest, however, in employing smaller lidar systems that require less power to enable sensing from small unmanned aerial vehicles or satellites. Technological advances in the performance of small microlasers and photodetector sensitivity have recently enabled the development of experimental airborne lidar systems with low signal-to-noise ratios (LSNRs). Recent government and academic prototypes have indicated that LSNR airborne lidars could significantly increase the fidelity of terrain reconstruction over what is possible with existing conventional lidars. Thus, there is a need to build up a modeling capability for such systems in order to aid in future system and mission design. A numerical sensor simulator has been developed to model the expected returns from LSNR microlaser altimeter systems and predict their performance. Both optical and signal processing system components are considered, along with other factors, including atmospheric effects and surface conditions. Topographic (solid Earth) and bathymetric (littoral zone) measurement scenarios are considered. The analysis of topographic simulation data focuses on the effect of solar noise on SNR and elevation accuracy while bathymetric performance is evaluated with regard to water depth and scan angle for different water clarities. The mission conditions chiefly responsible for limiting the performance of LSNR lidar are discussed in detail, along with suggestions for further algorithm development and system performance evaluation.

关键词： Bathymetry light detection and ranging (lidar) photonics simulation

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Autoregressive moving average modeling for spectral parameter estimation from a multigradient echo chemical shift acquisition

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MEDICAL PHYSICS 2009年第3期36卷 753-764页

作者： Taylor, Brian A. Hwang, Ken-Pin Hazle, John D. Stafford, R. Jason Univ Texas MD Anderson Canc Ctr Dept Imaging Phys Houston TX 77030 USA Univ Texas Houston Grad Sch Biomed Sci Houston TX 77030 USA GE Healthcare Appl Sci Lab Waukesha WI 53188 USA

The authors investigated the performance of the iterative Steiglitz-McBride (SM) algorithm on an autoregressive moving average (ARMA) model of signals from a fast, sparsely sampled, multiecho, chemical shift imaging (CSI) acquisition using simulation, phantom, ex vivo, and in vivo experiments with a focus on its potential usage in magnetic resonance (MR)-guided interventions. The ARMA signal model facilitated a rapid calculation of the chemical shift, apparent spin-spin relaxation time (T-2(*)), and complex amplitudes of a multipeak system from a limited number of echoes (<= 16). Numerical simulations of one- and two-peak systems were used to assess the accuracy and uncertainty in the calculated spectral parameters as a function of acquisition and tissue parameters. The measured uncertainties from simulation were compared to the theoretical Cramer-Rao lower bound (CRLB) for the acquisition. Measurements made in phantoms were used to validate the T-2(*) estimates and to validate uncertainty estimates made from the CRLB. We demonstrated application to real-time MR-guided interventions ex vivo by using the technique to monitor a percutaneous ethanol injection into a bovine liver and in vivo to monitor a laser-induced thermal therapy treatment in a canine brain. simulation results showed that the chemical shift and amplitude uncertainties reached their respective CRLB at a signal-to-noise ratio (SNR)>= 5 for echo train lengths (ETLs)>= 4 using a fixed echo spacing of 3.3 ms. T-2(*) estimates from the signal model possessed higher uncertainties but reached the CRLB at larger SNRs and/or ETLs. Highly accurate estimates for the chemical shift (< 0.01 ppm) and amplitude (< 1.0%) were obtained with >= 4 echoes and for T-2(*) (< 1.0%) with >= 7 echoes. We conclude that, over a reasonable range of SNR, the SM algorithm is a robust estimator of spectral parameters from fast CSI acquisitions that acquire <= 16 echoes for one- and two-peak systems. Preliminary ex vivo and in vivo

关键词： autoregressive moving average processes biomedical MRI biothermics brain chemical shift image sampling iterative methods laser applications in medicine liver medical image processing radiation therapy

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Balancing the Role of Priors in Multi-Observer Segmentation evaluation

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JOURNAL OF signal processing systems FOR signal image AND VIDEO TECHNOLOGY 2009年第1-3期55卷 185-207页

作者： Zhu, Yaoyao Huang, Xiaolei Wang, Wei Lopresti, Daniel Long, Rodney Antani, Sameer Xue, Zhiyun Thoma, George Lehigh Univ Dept Comp Sci & Engn Bethlehem PA 18015 USA Natl Inst Hlth Natl Lib Med Bethesda MD 20894 USA

Comparison of a group of multiple observer segmentations is known to be a challenging problem. A good segmentation evaluation method would allow different segmentations not only to be compared, but to be combined to generate a "true" segmentation with higher consensus. Numerous multi-observer segmentation evaluation approaches have been proposed in the literature, and STAPLE in particular probabilistically estimates the true segmentation by optimal combination of observed segmentations and a prior model of the truth. An Expectation-Maximization (EM) algorithm, STAPLE's convergence to the desired local minima depends on good initializations for the truth prior and the observer-performance prior. However, accurate modeling of the initial truth prior is nontrivial. Moreover, among the two priors, the truth prior always dominates so that in certain scenarios when meaningful observer-performance priors are available, STAPLE can not take advantage of that information. In this paper, we propose a Bayesian decision formulation of the problem that permits the two types of prior knowledge to be integrated in a complementary manner in four cases with differing application purposes: (1) with known truth prior;(2) with observer prior;(3) with neither truth prior nor observer prior;and (4) with both truth prior and observer prior. The third and fourth cases are not discussed (or effectively ignored) by STAPLE, and in our research we propose a new method to combine multiple-observer segmentations based on the maximum a posterior (MAP) principle, which respects the observer prior regardless of the availability of the truth prior. Based on the four scenarios, we have developed a web-based software application that implements the flexible segmentation evaluation framework for digitized uterine cervix images. Experiment results show that our framework has flexibility in effectively integrating different priors for multi-observer segmentation evaluation and it also generates results co

关键词： Ground truth Bayesian decision Precision Segmentation Multi-observer Sensitivity Specificity STAPLE Validation

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performance ASSESSMENT OF AN ACTIVE NOISE REDUCTION SYSTEM

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9th Biennial Conference on Engineering systems Design and Analysis

作者： Wolf, Kai Han, Soong-Oh Doll, Torsten Kurtze, Lothar Bein, Thilo Hanselka, Holger Tech Univ Darmstadt Chair Syst Reliabil & Machine Acoust Darmstadt Germany

ISBN: (纸本)9780791848364

In the past decade the field of smart structures and intelligent material systems received a lot of scientific attention. Numerous publications deal with the modeling, design, optimization and performance evaluation of such systems, in which beams, plates or truss structures are often considered as test cases. In the application of this promising new technology to real systems, the designer is often confronted with problem specific issues, e.g. proper formulation of the desired output function, integration of the actuators, sensors made of multifunctional materials and the control scheme to the system model, etc.. As an example, the performance assessment of an active facade system is presented in this paper. The facade system consists of distributed piezoelectric sensors and actuators bonded to the surface of the double-glazed windows. An adaptive feedforward control scheme was implemented to reduce the noise transmission via the active facade. The performance of the active system with four sensor/actuator pairs was First demonstrated in a numerical simulation. A Digital signal processing System was used to validate the performance of the system with the help of a demonstrator facade, showing the reduction of the ambient noise experimentally for different types of harmonic and transient excitation.

关键词： Digital signal processing

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Proceedings - 2009 International Conference on Embedded Computer systems: Architectures, modeling and simulation, IC-SAMOS 2009

Proceedings - 2009 International Conference on Embedded Comp...

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2009 International Conference on Embedded Computer systems: Architectures, modeling and simulation, IC-SAMOS 2009

ISBN: (纸本)9781424445011

The proceedings contain 23 papers. The topics discussed include: a mixed hardware-software approach to flexible artificial neural network training on FPGA;high-speed FPGA-based implementations of a genetic algorithm;high-level synthesis for the design of FPGA-based signal processing systems;a physical-level study of the compacted matrix instruction scheduler for dynamically-scheduled superscalar processors;instruction-based reuse-distance prediction for effective cache management;adaptive simulation sampling using an autoregressive framework;an emulation-based real-time power profiling unit for embedded software;generation and calibration of compositional performance analysis models for multi-processor systems;performance evaluation of concurrently executing parallel applications on multi-processor systems;and multi-processor system-on-chip design space exploration based on multi-level modeling techniques.

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signal processing Algorithm of Spaceborne SIMO HF-SAR for Three-Dimensional Topside Ionosphere Exploration

Signal Processing Algorithm of Spaceborne SIMO HF-SAR for Th...

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5th International Conference on Wireless Communications, Networking and Mobile Computing

作者： Chen, Jie Li, Zhuo Li, Chunsheng Zhou, Yinqing BeiHang Univ Sch Elect & Informat Engn Beijing 100191 Peoples R China

ISBN: (纸本)9781424436927

Ionosphere exploration is very important to improve the performance of space information systems, e.g. satellite navigation. A novel of spaceborne nadir-looking Single Input and Multiple Output (SIMO) HF-SAR is investigated, which has the capability to generate three-dimensional radar image for the topside ionospheric irregularities. The three-dimensional radar echo signal modeling is developed. The image formation algorithm for the antenna array typed SIMO HF-SAR system is proposed, based on modification of Extend Chirp Scaling (ECS) algorithm. Computer simulation results illustrate the feasibility, of new radar system and the validation of the signal processing algorithm. It has very good potential to be applied to the new generation ionospheric explorer developed in the future.

关键词： Synthetic Aperture Radar (SAR) Ionosphere Single Input Multiple Output (SIMO) High-Frequency image Formation

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A simulation program for the firefinder weapon locating radar

A simulation program for the firefinder weapon locating rada...

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modeling and simulation for Military Operations IV

作者： Lam, Eric P. Birrell, H. Walker Thales-Raytheon Systems Battlefield Radar Department 1801 Hughes Drive Fullerton CA 92834 United States

ISBN: (纸本)9780819476142

Thales-Raytheon systems' Firefinder PC simulation (PCS) tool allows a rapid simulated evaluation of Firefinder radar performance from a personal desktop computer. Firefinder radars are designed to track hostile rocket, artillery and mortar projectiles in order to accurately estimate weapon ground location. The Firefinder tactical code is used within PCS. This design provides a low risk path to rapid prototyping and evaluation of candidate software changes. PCS is used to evaluate candidate software changes to the Firefinder. Candidate design changes which perform well in PCS testing require minimum system level checkout before being checked into the tactical software baseline. The PCS tool contains a simulation engine which reads program control information from input data files. The PCS tool also generates and maintains simulated targets and clutter, simulates the radar signal processing function, performs Monte-Carlo "batch" processing, produces complex target trajectories internally or from an input text file and creates simulation data recording files identical in format to those created by the actual radar. This paper summarizes the capabilities of the Firefinder PCS and the additional of false location reduction features to the simulation. © 2009 SPIE.

关键词： Location

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simulation with Occupational Work Role Competences

Simulation with Occupational Work Role Competences

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2009 Grand Challenges in modeling and simulation Symposium, GCMS 2009

作者： Kantola, Jussi Piirto, Antti Toivonen, Jarmo Vanharanta, Hannu Yuseong-gu Daejeon305-701 Korea Republic of Teollisuuden Voima Oyj Olkiluoto EurajokiFI-27160 Finland Tampere University of Technology Institute of Signal Processing P.O. Box 553 TampereFIN-33101 Finland Tampere University of Technology at Pori Department of Industrial Management Pohjoisranta 11 A PL 300 Pori28101 Finland

ISBN: (纸本)9781622763610

Employees' personal capabilities and intentions indicate their performance in their organizations. This kind of tacit knowledge is therefore very important to capture. This paper examines how we can catch the inner voice of people by the means of simulation. The collective inner voice speaks loudly for the organizations and their managers. The process starts by competence self-evaluation conducted among employees. The goal is to grasp individuals' own perception and understanding of their vocational competences and their creative tension. A Self-Organizing Map is then created from the project dataset. A demonstrator tool, SIMU_SOM, allows doing what-if type of analysis/simulation on the SOM. This means that employees can roughly try the impact of alternative competence based training program for themselves. For individuals this may open new directions to develop themselves and for organizations, this allows efficient use of training and development resources. We tested the approach with two datasets from real HR development projects: office workers and nuclear power plant operators. Finally, does the simulation of human-systems really have intended impact in real world unless those humans are cognitively involved in the course of the simulation, as described here?. © 2009 Grand Challenges in modeling and simulation Symposium 2009, GCMS 2009 - Part of the 2009 Summer simulation Multiconference, SummerSim 2009. All rights reserved.

关键词： Self organizing maps

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Soft bit error modeling for discrete wireless channels 09

Soft bit error modeling for discrete wireless channels

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2009 ACM International Wireless Communications and Mobile Computing Conference, IWCMC 2009

作者： Salih, Omar S. Wang, Cheng-Xiang Laurenson, David I. Joint Research Institute for Signal and Image Processing School of EPS Heriot-Watt University Edinburgh EH14 4AS United Kingdom Joint Research Institute for Signal and Image Processing Institute for Digital Communications University of Edinburgh Edinburgh EH9 3JL United Kingdom

ISBN: (纸本)9781605585697

Soft decision decoding is currently used in many wireless communications systems because of its capability for increasing the coding gain. Soft generative models produce soft error sequences in order to help in the design and evaluation of the performance of many coding schemes and high layer wireless communication protocols. Errors in wireless fading channels are not independent but appear in bursts or clusters. In this paper, we design a soft Markovian based generative model with two embedded processes. The first process combines produced soft error bursts with soft errorfree bursts. Whereas, in the second process new error bursts are created according to the number of soft error clusters in each soft error burst of a reference soft error sequence. The reference soft error sequence is obtained from an enhanced general packet radio service (EGPRS) transmission system. The achieved results show a satisfactory behavior compared with the reference soft error sequence. Copyright 2009 ACM.

关键词： Hidden Markov models

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Research on the performance evaluation Technique for Communication Network

Research on the Performance Evaluation Technique for Communi...

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Congress on image and signal processing, CISP

作者： Ning Zhong Zun-wen He Jing-ming Kuang Jun Fang The Advanced Communication Laboratory Beijing Institute of Technology Beijing China Naval Aeronautical Engineering Institute Shandong China

A kind of performance evaluation for communication network is presented. In our work, a distributed evaluation system via High Level Architecture (HLA) and a novel quantitative evaluation method are proposed to evaluate communication network on-line. During the weight determination process, a combinative method based on the principle of maximum deviation and subjective estimation is proposed to overcome the weakness of subjectivity from the method of expert consultant. And an evaluation model based on the TOPSIS is provided to evaluate the performance of communication network. The experiments of communication survivability evaluation are executed on the distributed performance evaluation system. During the experiment, four types of Tactical Data Link are employed under the destruction experiment. The evaluation results with analysis show that the proposed method is satisfactory and the evaluation results are reasonable.

关键词： Communication networks Communication system control Computational modeling Computerized monitoring Computer architecture Computer simulation System testing Helium Aerospace engineering Software architecture

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