scholarly journals MIMO-SAR Interferometric Measurements for Structural Monitoring: Accuracy and Limitations

2021 ◽  
Vol 13 (21) ◽  
pp. 4290
Author(s):  
Andreas Baumann-Ouyang ◽  
Jemil Avers Butt ◽  
David Salido-Monzú ◽  
Andreas Wieser
Keyword(s):  
Multiple Input Multiple Output ◽  
Sampling Rate ◽  
Cost Effective ◽  
Meteorological Conditions ◽  
Deformation Monitoring ◽  
Sar Interferometry ◽  
High Temporal Resolution ◽  
Practical Applications ◽  
Temporal Sampling ◽  
Input Multiple Output

Terrestrial Radar Interferometry (TRI) is a measurement technique capable of measuring displacements with high temporal resolution at high accuracy. Current implementations of TRI use large and/or movable antennas for generating two-dimensional displacement maps. Multiple Input Multiple Output Synthetic Aperture Radar (MIMO-SAR) systems are an emerging alternative. As they have no moving parts, they are more easily deployable and cost-effective. These features suggest the potential usage of MIMO-SAR interferometry for structural health monitoring (SHM) supplementing classical geodetic and mechanical measurement systems. The effects impacting the performance of MIMO-SAR systems are, however, not yet sufficiently well understood for practical applications. In this paper, we present an experimental investigation of a MIMO-SAR system originally devised for automotive sensing, and assess its capabilities for deformation monitoring. The acquisitions generated for these investigations feature a 180∘ Field-of-View (FOV), distances of up to 60 m and a temporal sampling rate of up to 400 Hz. Experiments include static and dynamic setups carried out in a lab-environment and under more challenging meteorological conditions featuring sunshine, fog, and cloud-cover. The experiments highlight the capabilities and limitations of the radar, while allowing quantification of the measurement uncertainties, whose sources and impacts we discuss. We demonstrate that, under sufficiently stable meteorological conditions with humidity variations smaller than 1%, displacements as low as 25m can be detected reliably. Detecting displacements occurring over longer time frames is limited by the uncertainty induced by changes in the refractive index.

scholarly journals Automated terrestrial laser scanning with near-real-time change detection – monitoring of the Séchilienne landslide

2017 ◽  
Vol 5 (2) ◽  
pp. 293-310 ◽  
Author(s):  
Ryan A. Kromer ◽  
Antonio Abellán ◽  
D. Jean Hutchinson ◽  
Matt Lato ◽  
Marie-Aurelie Chanut ◽  
...  
Keyword(s):  
Change Detection ◽  
Real Time ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Cost Effective ◽  
Deformation Monitoring ◽  
Time Change ◽  
High Temporal Resolution ◽  
Atmospheric Conditions ◽  
Detection Processing

Abstract. We present an automated terrestrial laser scanning (ATLS) system with automatic near-real-time change detection processing. The ATLS system was tested on the Séchilienne landslide in France for a 6-week period with data collected at 30 min intervals. The purpose of developing the system was to fill the gap of high-temporal-resolution TLS monitoring studies of earth surface processes and to offer a cost-effective, light, portable alternative to ground-based interferometric synthetic aperture radar (GB-InSAR) deformation monitoring. During the study, we detected the flux of talus, displacement of the landslide and pre-failure deformation of discrete rockfall events. Additionally, we found the ATLS system to be an effective tool in monitoring landslide and rockfall processes despite missing points due to poor atmospheric conditions or rainfall. Furthermore, such a system has the potential to help us better understand a wide variety of slope processes at high levels of temporal detail.

scholarly journals Cross Regulation Reduced Optimal Multivariable Controller Design for Single Inductor DC-DC Converters

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 477 ◽  
Author(s):  
S. Augusti Lindiya ◽  
N. Subashini ◽  
K. Vijayarekha
Keyword(s):  
Pid Controller ◽  
Controller Design ◽  
Multiple Input Multiple Output ◽  
Linear Quadratic Regulator ◽  
Prototype Model ◽  
Linear Quadratic ◽  
Load Current ◽  
Practical Applications ◽  
Input Multiple Output ◽  
Single Input

Single Inductor (SI) converters with the advantage of using one inductor for any number of inputs/outputs find wide applications in portable electronic gadgets and electrical vehicles. SI converters can be used in Single Input Multiple Output (SIMO) and Multiple Input Multiple Output (MIMO) configurations but they need controllers to achieve good transient and steady state responses, to improve the stability against load and line disturbances and to reduce cross regulation. Cross regulation is the change in an output voltage due to change in the load current at another output and it is an added constraint in SI converters. In this paper, Single Input Dual Output (SIDO) and Dual Input Dual Output (DIDO) converters with applications capable of handling high load current working in Continuous Conduction Mode (CCM) of operation are taken under study. Conventional multivariable PID and optimal Linear Quadratic Regulator (LQR) controllers are developed and their performances are compared for the above configurations to meet the desired objectives. Generalized mathematical models for SIMO and MIMO are developed and a Genetic Algorithm (GA) is used to find the parameters of a multivariable PID controller and the weighting matrices of optimal LQR where the objective function includes cross regulation as a constraint. The simulated responses reveal that LQR controller performs well for both the systems over multivariable PID controller and they are validated by hardware prototype model with the help of DT9834® Data Acquisition Module (DAQ). The methodologies used here generate a fresh dimension for the case of such converters in practical applications.

scholarly journals SPARX, a MIMO Array for Ground-Based Radar Interferometry

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 252 ◽  
Author(s):  
Alberto Michelini ◽  
Francesco Coppi ◽  
Alberto Bicci ◽  
Giovanni Alli
Keyword(s):  
Multiple Input Multiple Output ◽  
Mimo Radar ◽  
Sar Interferometry ◽  
Open Pit ◽  
Acquisition Time ◽  
Atmospheric Effects ◽  
Mechanical Assembly ◽  
Input Multiple Output ◽  
Virtual Array ◽  
Interferometric Sar

Ground-Based SAR Interferometry (GB-InSAR) is nowadays a proven technique widely used for slope monitoring in open pit mines and landslide control. Traditional GB-InSAR techniques involve transmitting and receiving antennas moving on a scanner to achieve the desired synthetic aperture. Mechanical movement limits the acquisition speed of the SAR image. There is a need for faster acquisition time as it plays an important role in correcting rapidly varying atmospheric effects. Also, a fast imaging radar can extend the applications to the measurement of vibrations of large structures. Furthermore, the mechanical assembly put constraints on the transportability and weight of the system. To overcome these limitations an electronically switched array would be preferable, which however faces enormous technological and cost difficulties associated to the large number of array elements needed. Imaging Multiple-Input Multiple Output (MIMO) radars can be used as a significant alternative to usual mechanical SAR and full array systems. This paper describes the ground-based X-band MIMO radar SPARX recently developed by IDS GeoRadar in order to overcome the limits of IDS GeoRadar’s well-established ground based interferometric SAR systems. The SPARX array consists of 16 transmit and 16 receive antennas, organized in independent sub-modules and geometrically arranged in order to synthesize an equally spaced virtual array of 256 elements.

scholarly journals CLAAS: the CM SAF cloud property data set using SEVIRI

2014 ◽  
Vol 14 (8) ◽  
pp. 4297-4311 ◽  
Author(s):  
M. Stengel ◽  
A. Kniffka ◽  
J. F. Meirink ◽  
M. Lockhoff ◽  
J. Tan ◽  
...  
Keyword(s):  
Near Infrared ◽  
Spatial Scales ◽  
Sampling Rate ◽  
High Temporal Resolution ◽  
Cloud Detection ◽  
Data Set ◽  
Cloud Property ◽  
Temporal Sampling ◽  
Cloud Properties ◽  
The Impact

Abstract. An 8-year record of satellite-based cloud properties named CLAAS (CLoud property dAtAset using SEVIRI) is presented, which was derived within the EUMETSAT Satellite Application Facility on Climate Monitoring. The data set is based on SEVIRI measurements of the Meteosat Second Generation satellites, of which the visible and near-infrared channels were intercalibrated with MODIS. Applying two state-of-the-art retrieval schemes ensures high accuracy in cloud detection, cloud vertical placement and microphysical cloud properties. These properties were further processed to provide daily to monthly averaged quantities, mean diurnal cycles and monthly histograms. In particular, the per-month histogram information enhances the insight in spatio-temporal variability of clouds and their properties. Due to the underlying intercalibrated measurement record, the stability of the derived cloud properties is ensured, which is exemplarily demonstrated for three selected cloud variables for the entire SEVIRI disc and a European subregion. All data products and processing levels are introduced and validation results indicated. The sampling uncertainty of the averaged products in CLAAS is minimized due to the high temporal resolution of SEVIRI. This is emphasized by studying the impact of reduced temporal sampling rates taken at typical overpass times of polar-orbiting instruments. In particular, cloud optical thickness and cloud water path are very sensitive to the sampling rate, which in our study amounted to systematic deviations of over 10% if only sampled once a day. The CLAAS data set facilitates many cloud related applications at small spatial scales of a few kilometres and short temporal scales of a~few hours. Beyond this, the spatiotemporal characteristics of clouds on diurnal to seasonal, but also on multi-annual scales, can be studied.

scholarly journals MIMO SAR FORMATIONS: ORBITAL DIAMETER AND SYNCHRONIZATION TOLERANCES

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 631-635
Author(s):  
A. Monti Guarnieri ◽  
D. Giudici ◽  
P. Guccione ◽  
M. Manzoni ◽  
F. Rocca
Keyword(s):  
Pulse Repetition Frequency ◽  
Multiple Input Multiple Output ◽  
Cost Effective ◽  
Power Resources ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Single Input ◽  
Small Antenna ◽  
Along Track ◽  
The Impact

Abstract. Multiple-Input-Multiple Output (MIMO) Synthetic Aperture Radar (SAR) along-track formations can be used to fraction the power resources into compact, lightweight and cost-effective satellites, or to extend the swath coverage beyond the limit provided by a small antenna. In this second case, the Pulse Repetition Frequency (PRF) is kept low by implementing an inversion that solves up to N−1 ambiguities, given N observations. The simultaneous illumination – that allows for the N² gain due to the coherent combination of the N transmitters and the N receivers, is analyzed and shown not to be critical, as the more than N=2 sensors are assumed. Performance is evaluated for the N=2 and N=3 cases and compared with the Single Input Multiple Output formations, where one sensor is transmitting, and all are receiving. Finally, the impact of the across-track deviation from the orbit is modeled and evaluated.

scholarly journals CLAAS: the CM SAF cloud property dataset using SEVIRI

2013 ◽  
Vol 13 (10) ◽  
pp. 26451-26487 ◽  
Author(s):  
M. Stengel ◽  
A. Kniffka ◽  
J. F. Meirink ◽  
M. Lockhoff ◽  
J. Tan ◽  
...  
Keyword(s):  
Near Infrared ◽  
Spatial Scales ◽  
Sampling Rate ◽  
High Temporal Resolution ◽  
Cloud Detection ◽  
Cloud Property ◽  
Diurnal Cycles ◽  
Temporal Sampling ◽  
Cloud Properties ◽  
The Impact

Abstract. An 8 yr record of satellite based cloud properties named CLAAS (CLoud property dAtAset using SEVIRI) is presented, which was derived within the EUMETSAT Satellite Application Facility on Climate Monitoring. The dataset is based on SEVIRI measurements of the Meteosat Second Generation satellites, of which the visible and near-infrared channels were intercalibrated with MODIS. Including latest development components of the two applied state-of-the-art retrieval schemes ensure high accuracy in cloud detection, cloud vertical placement and microphysical cloud properties. These properties were further processed to provide daily to monthly averaged quantities, mean diurnal cycles and monthly histograms. In particular the collected histogram information enhance the insight in spatio-temporal variability of clouds and their properties. Due to the underlying intercalibrated measurement record, the stability of the derived cloud properties is ensured, which is exemplarily demonstrated for three selected cloud variables for the entire SEVIRI disk and a European subregion. All data products and processing levels are introduced and validation results indicated. The sampling uncertainty of the averaged products in CLAAS is minimized due to the high temporal resolution of SEVIRI. This is emphasized by studying the impact of reduced temporal sampling rates taken at typical overpass times of polar-orbiting instruments. In particular cloud optical thickness and cloud water path are very sensitive to the sampling rate, which in our study amounted to systematic deviations of over 10% if only sampled once a day. The CLAAS dataset facilitates many cloud related applications at small spatial scales of a few kilometres and short temporal scales of a few hours. Beyond this, the spatiotemporal characteristics of clouds on diurnal to seasonal, but also on multi-annual scales, can be studied.

scholarly journals Linear Precoding Designs for MIMO VLC Using Multi-Color LEDs under Multiple Lighting Constraints

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 408 ◽  
Author(s):  
Ye Xiao ◽  
Yi-Jun Zhu ◽  
Zheng-Guo Sun
Keyword(s):  
High Speed ◽  
Mean Squared Error ◽  
Transmission Rate ◽  
Multiple Input Multiple Output ◽  
Visible Light Communication ◽  
Mimo Channel ◽  
Practical Applications ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Mimo Technology

Multiple-input multiple-output (MIMO) technology as an efficient approach to improve the transmission rate in visible light communication (VLC) has been well studied in recent years. In this paper, we focus on the MIMO VLC system using multi-color LEDs in the typical indoor scenario. Besides the correlation of the MIMO channel, the multi-color crosstalk interference and quadrangle chromaticity region are also considered to increase the practicality of this system. With the constraints of power, amplitude and chromaticity, an iterative algorithm to minimize mean-squared-error (MSE) is proposed to jointly design the precoder and equalizer. Our proposed algorithm provides an effective method to get the optimal precoder by updating optimization variables iteratively. As the equalizer matrix is fixed at each iteration, the main non-convex precoding design problem is transformed into a convex optimization problem and then solved. With the utilization of multi-color LEDs, our proposed precoding method would be promising to promote the practical applications of high-speed indoor optical wireless communication. Simulation results show that our proposed method owns better performance than conventional chromaticity-fixed schemes and zero-forcing precoding designs.

scholarly journals Constructing Dynamic Multiple-Input Multiple-Output Logic Gates

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Haipeng Peng ◽  
Gang Hu ◽  
Lixiang Li ◽  
Yixian Yang ◽  
Jinghua Xiao
Keyword(s):  
Noise Analysis ◽  
Multiple Input Multiple Output ◽  
Clock Cycle ◽  
Dynamic Logic ◽  
Logic Gates ◽  
Cost Effective ◽  
Research Direction ◽  
Threshold Method ◽  
Multiple Input ◽  
Input Multiple Output

Investigation of computing devices with dynamic architecture which makes devices have reconfigurable ability is an interesting research direction for designing the next generation of computer chip. In this paper, we present a window threshold method to construct such dynamic logic architecture. Here, dynamic multiple-input multiple-output (MIMO) logic gates are proposed, analyzed, and implemented. By using a curve-intersections-based graphic method, we illustrate the relationships among the threshold, the control parameter, and the functions of logic gates. A noise analysis on all the parameters is also given. The chips based on the proposed schemes can be transformed into different arrangements of logic gates within a single clock cycle. With these schemes in hand, it is conceivable to build more flexible, robust, cost effective, yet general-purpose computing devices.

scholarly journals Performance Analysis of Large Intelligent Reflecting Surface Aided Moderate MIMO for 5G Communication

2021 ◽  
Author(s):  
Fitsum Dessalegn Mekonnen ◽  
Muluneh Mekonnen Tulu ◽  
Sultan Feisso
Keyword(s):  
Energy Efficiency ◽  
Multiple Input Multiple Output ◽  
Cost Effective ◽  
Access Point ◽  
Wireless Channel ◽  
Transmit Power ◽  
Alternating Direction ◽  
Input Multiple Output ◽  
Reflecting Surfaces ◽  
Reflecting Surface

Abstract The recently completed 5G framework is the outcome of a few advanced technologies. Massive Multiple Input Multiple Output (MIMO), millimeter wave communication, and network densification are examples of these technologies. However, there are two disadvantages to this technology.1) the lack of control over the wireless channel, and 2) the wireless interface’s excessive power consumption. The concept of re-configurable Intelligent Reflecting Surfaces has emerged to answer the need for green and cost-effective future cellular networks. In this study, we’ll look at how using an Intelligent Reflecting Surface (IRS) improve the performance of moderate MIMO communication in terms of the rate, SINR, Energy efficiency and transmit power metrics. Despite the fact that the underlying issue is non-convexity, we use Lagrangian dual transform and Quadratic Transform to change and rearrange the original issue. After that, active and passive beam forming improved alternatively using an alternating Direction method of multiplier algorithm (ADMM.The IRS-aided system with a reasonable number of antennas at the access point (AP) outperforms the massive MIMO without IRS in terms of sum rate, SINR, Energy efficiency and transmit power metrics.

scholarly journals Metrics and Methods for Evaluation of Over-The-Air Performance of MIMO User Equipment

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Yifei Feng ◽  
Werner L. Schroeder ◽  
Christoph von Gagern ◽  
Adam Tankielun ◽  
Thomas Kaiser
Keyword(s):  
Performance Metrics ◽  
Multiple Input Multiple Output ◽  
Cost Effective ◽  
Low Complexity ◽  
User Equipment ◽  
Single Input Single Output ◽  
Operating Modes ◽  
Single Output ◽  
Input Multiple Output ◽  
Physical Attributes

Commercial User Equipment (UE) testing and certification has become more complex for state-of-the-art mobile communication standards such as 3rd Generation Partnership Project (3GPP) Long-Term Evolution (LTE) due to the extensive use of Multiple Input-Multiple Output (MIMO) transmission techniques. The variety of different MIMO operating modes and the almost unlimited choice of possible multipath channel conditions under which UE performance may be evaluated are not accounted for by established Single Input-Single Output (SISO) Over-The-Air (OTA) performance metrics like Total Isotropic Sensitivity (TIS) and Total Radiated Power (TRP). As pointed out in this contribution, meaningful metrics and cost-effective, low-complexity measurement methods can, nevertheless, be derived by focusing on characterization of the physical attributes of UE and by adopting statistical metrics. Starting from a brief review of the most important MIMO operating modes in the 3GPP LTE standard, the relation between UE properties and UE performance, which is observed in these operating modes, is discussed. Two complementary metrics and corresponding measurement procedures for evaluation of MIMO OTA performance are presented in order to address the diversity of possible propagation scenarios. Measurement results from preliminary implementations of the two proposed measurement procedures, including comparison between different LTE devices, are presented.

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