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Faculty Publications

2004

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Articles 1 - 30 of 86

Full-Text Articles in Engineering

Failure In Internally Pressurized Bent Tubes, Robin Stevenson, Boon-Chai Ng, Peter Polidoro Dec 2004

Failure In Internally Pressurized Bent Tubes, Robin Stevenson, Boon-Chai Ng, Peter Polidoro

Faculty Publications

The analysis and modeling of tube-hydroformed components is more complicated than that employed for sheet-metal panels, due to the lengthier process sequence and variable strain path - from flat-rolled sheet to tube; from straight tube to bent tube; and from bent tube to hydroformed component. These additional process steps make it difficult to determine whether post mortem analyses of tube failure during hydroforming can, and should, be conducted with the same tools and databases as used for simple stampings. To provide a partial answer, the properties of commercially fabricated welded straight tubes were evaluated using a free-expansion internal pressure test …

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The Effect Of Gas Pressure On No Conversion Energy Efficiency In Nonthermal Nitrogen Plasma, Morris D. Argyle, Gui-Bing Zhao, S.V.B. Janardhan Garikipati, Xudong Hu, Maciej Radosz Nov 2004

The Effect Of Gas Pressure On No Conversion Energy Efficiency In Nonthermal Nitrogen Plasma, Morris D. Argyle, Gui-Bing Zhao, S.V.B. Janardhan Garikipati, Xudong Hu, Maciej Radosz

Faculty Publications

This work explores the effect of gas pressure on the rate of electron collision reactions and energy consumption for NO conversion in N2 in a pulsed corona discharge reactor. A previous study showed that the rate constant of electron collision reactions, multiplied by the electron concentration, can be expressed as k[e] = βα−0.5P−0.5W0.75exp(−αP/W). The model parameter α remains constant with increasing gas pressure, which verifies the previous assumption that the electron temperature is inversely proportional to gas pressure. However, the model parameter β decreases with increasing gas pressure, which indicates that the rate constant of electron collision reactions decreases with …

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Kalman Consensus Strategies And Their Application To Cooperative Control, Randal Beard, Derek Kingston, Wei Ren Nov 2004

Kalman Consensus Strategies And Their Application To Cooperative Control, Randal Beard, Derek Kingston, Wei Ren

Faculty Publications

Sponsorship: AFOSR, NSF. In this paper, we propose discrete-time and continuous-time consensus update schemes motivated by the discrete-time and continuous-time Kalman filters. With certainty information encoded into each agent, the proposed consensus schemes explicitly account for relative confidence in the information that is communicated from each agent in the team. We show mild sufficient conditions under which consensus can be achieved using the proposed schemes in the presence of switching interaction topologies. The Kalman consensus scheme is shown to be input-to-state stable. We show how to exploit this fact in multi-agent cooperative control scenarios.

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Simulation Of Gate Lag And Current Collapse In Gallium Nitride Field-Effect Transistors, N. Braga, R. Mickevicius, R. Gaska, M. S. Shur, M. Asif Khan, Grigory Simin Nov 2004

Simulation Of Gate Lag And Current Collapse In Gallium Nitride Field-Effect Transistors, N. Braga, R. Mickevicius, R. Gaska, M. S. Shur, M. Asif Khan, Grigory Simin

Faculty Publications

Results of two-dimensional numerical simulations of gate lag and current collapse in GaN heterostructurefield-effect transistors are presented. Simulation results clearly show that current collapse takes place only if an enhanced trapping occurs under the gate edges. Hot electrons play an instrumental role in the collapse mechanism. The simulation results also link the current collapse with electrons spreading into the buffer layer and confirm that a better electron localization (as in a double heterostructurefield-effect transistor) can dramatically reduce current collapse.

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Coordination Variables And Consensus Building In Multiple Vehicle Systems, Tim Mclain Nov 2004

Coordination Variables And Consensus Building In Multiple Vehicle Systems, Tim Mclain

Faculty Publications

Much of the research focus in the cooperative control community has been on formation control problems. This focus may be due to the fact that the group control problem can be reduced to well-established single-agent control problems by employing a leader-follower type control strategy. For example, single-agent path planning and trajectory generation techniques can be employed for the leader, and conventional trajectory tracking strategies can be employed for the followers. Indeed, formation control problems are much like linear systems theory: we search where the light is the brightest. It can be argued that formation control problems are the simplest type …

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Evaluation Of Bus And Truck Automation Operations Concepts, H.-S. Jacob Tsao, Lan Zhang, Lin Lin, Deepa Batni Nov 2004

Evaluation Of Bus And Truck Automation Operations Concepts, H.-S. Jacob Tsao, Lan Zhang, Lin Lin, Deepa Batni

Faculty Publications

Traffic congestion will continue to worsen and likely worsen at a faster rate than ever. People throughput and freight throughput have become critical issues for California and the rest of the nation. PATH has funded with approximately $125K a research project entitled “Evaluation of Bus and Truck Automation Scenarios” jointly proposed by Jan Botha (Principal Investigator) of Department of Civil and Environmental Engineering and Jacob Tsao (Co-PI) of Department of Industrial and Systems Engineering at San Jose State University. This report summarizes the major findings of the research conducted by Professor Tsao and his assistants with approximately $44K out of …

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A Review Of Antennas And Propagation For Mimo Wireless Communications, Michael A. Jensen, Jon W. Wallace Nov 2004

A Review Of Antennas And Propagation For Mimo Wireless Communications, Michael A. Jensen, Jon W. Wallace

Faculty Publications

Multiple-input-multiple-output (MIMO) wireless systems use multiple antenna elements at transmit and receive to offer improved capacity over single antenna topologies in multipath channels. In such systems, the antenna properties as well as the multipath channel characteristics play a key role in determining communication performance. This paper reviews recent research findings concerning antennas and propagation in MIMO systems. Issues considered include channel capacity computation, channel measurement and modeling approaches, and the impact of antenna element properties and array configuration on system performance. Throughout the discussion, outstanding research questions in these areas are highlighted.

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Resolution Scaling In Noncontact Scanning Impedance Imaging, Benjamin C. Green, Tao Shang, Jacey C. Morine, Hongze Liu, Stephen M. Schultz, Travis E. Oliphant, Aaron R. Hawkins Oct 2004

Resolution Scaling In Noncontact Scanning Impedance Imaging, Benjamin C. Green, Tao Shang, Jacey C. Morine, Hongze Liu, Stephen M. Schultz, Travis E. Oliphant, Aaron R. Hawkins

Faculty Publications

Noncontact scanning impedance imaging has been presented as a method to provide high resolution, high contrast images for a variety of material systems. This technique combines electrical impedance measurements with very high resolution scanning. This article reports on efforts to scale this technique down to the very important single micron range and reveals measurements for both thick and thin samples with a measured minimum resolution below 30 µm. A design for a shielded impedance probe applicable to this process is outlined and probes of several different sizes were made and tested. Fabrication of these impedance probes is explained and a …

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Integrated Optical Waveguides With Liquid Cores, Aaron R. Hawkins, John P. Barber, Dongliang Yin, D. W. Deamer, Holger Schmidt Oct 2004

Integrated Optical Waveguides With Liquid Cores, Aaron R. Hawkins, John P. Barber, Dongliang Yin, D. W. Deamer, Holger Schmidt

Faculty Publications

We report the design, fabrication, and demonstration of single-mode integrated optical waveguides with liquid cores. The principle of the device is based on antiresonant reflecting optical (ARROW) waveguides with hollow cores. We describe design principles for waveguide loss optimization down to 0.1/cm. Using a fabrication process based on conventional silicon microfabrication and sacrificial core layers, waveguides of varying widths and lengths with volumes covering the pico- to nanoliter range were fabricated. We observe confined mode propagation, measure waveguide losses of 2.4/cm, and demonstrate that the waveguides possess tailorable wavelength selectivity. The potential for highly integrated, sensitive devices based on these …

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Wind Speed Effect On L-Band Brightness Temperature Inferred From Eurostarrs And Wise 2001 Field Experiments, David G. Long, Jacqueline Etcheto, Emmanuel P. Dinnat, Jacqueline Boutin, Adriano Camps, Stephanie Contardo, J. Wesson, Jordi Font, J. Miller Oct 2004

Wind Speed Effect On L-Band Brightness Temperature Inferred From Eurostarrs And Wise 2001 Field Experiments, David G. Long, Jacqueline Etcheto, Emmanuel P. Dinnat, Jacqueline Boutin, Adriano Camps, Stephanie Contardo, J. Wesson, Jordi Font, J. Miller

Faculty Publications

The results from two field experiments in the Mediterranean Sea are used to study the wind speed dependence of brightness temperature at L-band. During the EuroSTARRS airborne experiment, an L-band radiometer made measurements across a large wind speed gradient, enabling us to study this dependence at high wind speed. We compare our results with a two-scale emissivity model using several representations of the sea state spectrum. While the results are encouraging, unfortunately the accuracy of the measurements does not permit us to distinguish between the so-called twice Durden and Vesecky spectrum and the Elfouhaily spectrum above 7 m X s-1. …

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Semi-Autonomous Human-Uav Interfaces For Fixed-Wing Mini-Uavs, Randal Beard, Michael A. Goodrich, Morgan Quigley Oct 2004

Semi-Autonomous Human-Uav Interfaces For Fixed-Wing Mini-Uavs, Randal Beard, Michael A. Goodrich, Morgan Quigley

Faculty Publications

Sponsorship: DARPA, AFOSR. We present several human-robot interfaces that support real-time control of a small semi-autonomous UAV. These interfaces are designed for searching tasks and other missions that typically do not have a precise predetermined flight plan. We present a detailed analysis of a PDA interface and describe how our other interfaces relate to this analysis. We then offer quantative and qualitative performance comparisons of the interfaces, as well as an analysis of their possible real-world applications.

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High Order Convergence With A Low Order Discretization Of The 2d Mfie, Clayton P. Davis, Karl F. Warnick Sep 2004

High Order Convergence With A Low Order Discretization Of The 2d Mfie, Clayton P. Davis, Karl F. Warnick

Faculty Publications

Moment method solutions to the MFIE are often less accurate for a given grid than corresponding solutions to the EFIE. We propose that the cause of this observation is the identity operator in the MFIE and show how regularizing the identity increases the convergence rate of the discretized 2D MFIE by three orders.

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Electromagnetic Bias At Off-Nadir Incidence Angles, David V. Arnold, Floyd W. Millet, Karl F. Warnick Sep 2004

Electromagnetic Bias At Off-Nadir Incidence Angles, David V. Arnold, Floyd W. Millet, Karl F. Warnick

Faculty Publications

Sponsorship: JPL Subcontract 961461. Nadir and off-nadir measurements of electromagnetic (EM) bias measurements are presented and compared with an off-nadir bias model. Measurements of the bias were made during the BYU Off-Nadir Experiment (Y-ONE) in the months of March and April, 2003. Using radar measurements of the surface and backscattered power, the EM bias was computed at angles from nadir to 17º degrees. Simultaneous surface measurements from a laser rangefinder provide accurate measurements of the long wave surface parameters. An off-nadir bias model incorporating the effects of hydrodynamic modulation of short waves and tilt modulation of long waves is developed …

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Evaluation Of Power Costs In Applying Tmr To Fpga Designs, Nathaniel Rollins, Michael J. Wirthlin, Paul S. Graham Sep 2004

Evaluation Of Power Costs In Applying Tmr To Fpga Designs, Nathaniel Rollins, Michael J. Wirthlin, Paul S. Graham

Faculty Publications

Sponsorship: Los Alamos National Laboratory. Triple modular redundancy (TMR) is a technique commonly used to mitigate against design failures caused by single event upsets (SEUs). The SEU immunity that TMR provides comes at the cost of increased design area and decreased speed. Additionally, the cost of increased power due to TMR must be considered. This paper evaluates the power costs of TMR and validates the evaluations with actual measurements. Sensitivity to design placement is another important part of this study. Power consumption costs due to TMR are also evaluated in different FPGA architectures. This study shows that power consumption rises …

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Initial Experiments In The Cooperative Control Of Unmanned Air Vehicles, Derek R. Nelson, Timothy W. Mclain, Reed S. Christiansen, Randal W. Beard, David Johansen Sep 2004

Initial Experiments In The Cooperative Control Of Unmanned Air Vehicles, Derek R. Nelson, Timothy W. Mclain, Reed S. Christiansen, Randal W. Beard, David Johansen

Faculty Publications

This paper addresses cooperative control for a team of unmanned air vehicles (UAVs). Specifically, a team of three small UAVs is controlled to perform a cooperative timing mission. Starting at loiter locations distributed around the periphery of a 2 km square battle area, the UAVs cooperatively plan paths to arrive at a target at the center of the battle area in sequence at 10 sec intervals. Cooperative path planning is performed using the methodology of coordination variables and coordination functions. Coordination and waypoint path planning are centralized on a ground station computer. Experiments have been performed using BYU’s fleet of …

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Detection Of Configuration Memory Upsets Causing Persistent Errors In Sram-Based Fpgas, D. Eric Johnson, Keith S. Morgan, Michael J. Wirthlin, Michael P. Caffrey, Paul S. Graham Sep 2004

Detection Of Configuration Memory Upsets Causing Persistent Errors In Sram-Based Fpgas, D. Eric Johnson, Keith S. Morgan, Michael J. Wirthlin, Michael P. Caffrey, Paul S. Graham

Faculty Publications

Sponsorship: Los Alamos National Laboratory. FPGA designers are becoming increasingly aware of fault tolerance issues in modern FPGA designs, especially designs destined for a radiation environment. We classify errors due to upsets within the configuration bitstream into two categories; namely, persistent and non-persistent. Persistent errors generally cannot be tolerated. However, non-persistent errors can be tolerated in certain types of designs as long as they are properly accounted for. We discuss situations in which non-persistent errors are acceptable, and describe a technique for the detection of upsets causing persistent errors within the configuration memor of an SRAM-based FPGA.

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Every Polynomial-Time 1-Degree Collapses If And Only If P=Pspace, Stephen A. Fenner, Stuart A. Kurtz, James S. Royer Sep 2004

Every Polynomial-Time 1-Degree Collapses If And Only If P=Pspace, Stephen A. Fenner, Stuart A. Kurtz, James S. Royer

Faculty Publications

No abstract provided.

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Optimal Sampling For Single-Tone Frequency Estimation, Travis E. Oliphant Aug 2004

Optimal Sampling For Single-Tone Frequency Estimation, Travis E. Oliphant

Faculty Publications

Single-tone frequency estimation from irregularly spaced samples is analyzed. The ratio of the Cramr-Rao Bound (CRB) for regularly spaced samples to the bound for irregularly spaced samples is presented and shown to be a globally convex function. It's minima and maxima over the domain of interest are identified which reveals that improvements in the CRB can be obtained using non-equally-spaced samples. For a given sampling density, the best estimates of frequency are obtained when half of the samples are taken at one end of the total available interval and the remaining samples are taken at the other end.

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Noncontact Scanning Impedance Imaging In An Aqueous Solution, Aaron R. Hawkins, Hongze Liu, Travis E. Oliphant, Stephen M. Schultz Aug 2004

Noncontact Scanning Impedance Imaging In An Aqueous Solution, Aaron R. Hawkins, Hongze Liu, Travis E. Oliphant, Stephen M. Schultz

Faculty Publications

We present a method for imaging based on noncontact electrical impedance measurements and mechanical scanning. Measurement results are shown for an initial system based on this concept. An impedance probe design is presented, applicable to the test system. Line-scan data plots of high impedance contrast structures show a good fit to a theoretical physical model. Image resolutions on the order of 100 m are indicated for the initial system. Two-dimensional impedance images of biological tissue generated by this technique are shown.

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Percolation Paths Of Three-Dimensions In Sensitized Stainless Steel, Alisa J. Millar Henrie Aug 2004

Percolation Paths Of Three-Dimensions In Sensitized Stainless Steel, Alisa J. Millar Henrie

Faculty Publications

The study of three-dimensional percolation paths through materials is important in its contribution to understanding defect sensitive properties of materials. This work shows the importance of grain boundary character in modeling defect sensitive boundaries. Also presented are trends of percolation of sensitized grain boundaries in 304 stainless steel (304SS). Of particular interest is how open paths form in a three-dimensional model created through serial sectioning. Evidence is presented that triple or quadruple points that contain typically two boundaries with special character that intersect the percolation path break up the path. Some boundaries with no known special qualities; they are not …

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High Efficiency 90 Degree Silica Waveguide Bend Using An Air Hole Photonic Crystal Region, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang Aug 2004

High Efficiency 90 Degree Silica Waveguide Bend Using An Air Hole Photonic Crystal Region, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang

Faculty Publications

We propose the hybrid integration of an air hole photonic crystal (PhC) structure with a high (0.75%) single-mode silica waveguide to achieve an ultracompact high efficiency 90 bend for transverse-magnetic polarized light. Diffraction from the periodic boundary between the PhC and silica waveguide regions is shown to seriously degrade the optical efficiency of the bend. A microgenetic algorithm ( GA) combined with a two-dimensional finite-difference time-domain method is used to modify the PhC and its boundary layer to suppress this diffraction which in turn maximizes bend efficiency. The final optimized structure has a 99.4% bend efficiency at a wavelength of …

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3d Analysis Of Hybrid Photonic Crystal/Conventional Waveguide 90° Bend, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang Jul 2004

3d Analysis Of Hybrid Photonic Crystal/Conventional Waveguide 90° Bend, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang

Faculty Publications

We present a three-dimensional (3D) analysis of a hybrid photonic crystal conventional waveguide 90° bend proposed previously [Opt. Express 10, 1334 (2002)] as an ultracompact component for large-scale planar lightwave circuit integration. Both rigorous 3D finite-difference time-domain modeling and a simple perfect mirror model analysis were carried out for different Si post heights in the photonic crystal region. Results show that the bend efficiency increases rapidly with Si post height. For a post height of 6.5 µm, this structure yields a bend efficiency of 97.3% at a wavelength of 1.55 µm for 90° bends in 2 µm X 2 µm …

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Cavity Enhancement Of The Magneto-Optic Kerr Effect For Optical Studies Of Magnetic Nanostructures, Aaron R. Hawkins, N. Qureshi, Holger Schmidt Jul 2004

Cavity Enhancement Of The Magneto-Optic Kerr Effect For Optical Studies Of Magnetic Nanostructures, Aaron R. Hawkins, N. Qureshi, Holger Schmidt

Faculty Publications

We present a study of cavity enhancement of the magneto-optic Kerr effect using dielectric multilayers in order to facilitate optical studies of individual single-domain nanomagnets. We develop a transfer matrix theory to analyze Kerr rotation from an arbitrary number of possibly lossy dielectric layers. The combination of one lossless and one thin metallic layer is found to be most favorable for studying individual nanomagnets, providing the best tradeoff between signal enhancement and spatial resolution. Accounting for the microscopic surface structure, we find good agreement between theory and experiment. Using this technique, we demonstrate Kerr enhancements by a factor of more …

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Measuring The Five-Parameter Grain-Boundary Distribution From Observations Of Planar Sections, Brent L. Adams, Bassem S. El-Dasher, Gregory S. Rohrer, David M. Saylor Jul 2004

Measuring The Five-Parameter Grain-Boundary Distribution From Observations Of Planar Sections, Brent L. Adams, Bassem S. El-Dasher, Gregory S. Rohrer, David M. Saylor

Faculty Publications

One of the authors (DMS) thanks his colleagues at NIST, Edwin R. Fuller, Jr. and Grady S. White, for their helpful advice and criticisms, as well as Mark D. Vaudin and James A. Warren for their critical review of this manuscript. This work was supported at CMU by the MRSEC program of the National Science Foundation under Award No. DMR-0079996. A sterological method is described for estimating the distribution of grain-boundary types in poly-crystalline materials on the basis of observations from a single planar section. The grain-boundary distribution is expressed in terms of five macroscopically observable parameters that include: three …

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New Stereology For The Recovery Of Grain-Boundary Plane Distributions In The Crystal Frame, Brent L. Adams, Ryan J. Larsen Jul 2004

New Stereology For The Recovery Of Grain-Boundary Plane Distributions In The Crystal Frame, Brent L. Adams, Ryan J. Larsen

Faculty Publications

One of the authors (RJL) is grateful to the Office of Naval Research for fellowship support. BLA acknowledges the support of the NSF through the Materials Research Science and Engineering Center, Carnegie Mellon University (Grant No. DMR-0079996). A new experimental method is given for recovering the probability-distribution function Sv(ns/g). The function Sv(na/g) is the grain-boundary area per unit volume as a function of grain-boundary plane orientation (na), given a lattice misorientation (g) between the adjoining grains. The grain-boundary normal (na) is expressed in the crystal frame in which the misorientation g originates. The proposed method recovers the three-dimensional Sv(na/g) function …

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Mutual Coupling In Mimo Wireless Systems: A Rigorous Network Theory Analysis, Michael A. Jensen, Jon W. Wallace Jul 2004

Mutual Coupling In Mimo Wireless Systems: A Rigorous Network Theory Analysis, Michael A. Jensen, Jon W. Wallace

Faculty Publications

A new framework for the analysis of multiple-input multiple-output (MIMO) wireless systems is introduced to account for mutual coupling effects in the antenna arrays. The multiport interactions at transmit and receive are characterized by representing the channel using a scattering parameter matrix. A new power constraint that limits the average radiated power is also introduced. The capacity of the MIMO system with mutual coupling is defined as the maximum mutual information of the transmit and receive vectors over all possible transmit signaling and receive loading. Full-wave electromagnetic antenna simulations combined with a simple path-based channel model are used to demonstrate …

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Simultaneous Wind And Rain Retrieval Using Seawinds Data, David G. Long, David W. Draper Jul 2004

Simultaneous Wind And Rain Retrieval Using Seawinds Data, David G. Long, David W. Draper

Faculty Publications

The SeaWinds scatterometers onboard the QuikSCAT and the Advanced Earth Observing Satellite 2 measure ocean winds on a global scale via the relationship between the normalized radar backscattering cross section of the ocean and the vector wind. The current wind retrieval method ignores scattering and attenuation of ocean rain, which alter backscatter measurements and corrupt retrieved winds. Using a simple rain backscatter and attenuation model, two methods of improving wind estimation in the presence of rain are evaluated. First, if no suitable prior knowledge of the rain rate is available, a maximum-likelihood estimation technique is used to simultaneously retrieve the …

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Unmanned Air Vehicle Testbed For Cooperative Control Experiments, Timothy W. Mclain, Randal W. Beard Jul 2004

Unmanned Air Vehicle Testbed For Cooperative Control Experiments, Timothy W. Mclain, Randal W. Beard

Faculty Publications

This paper describes the MAGICC Lab unmanned air vehicle (UAV) testbed at Brigham Young University. Motivation for pursuing experimental research with UAVs is given as well as a historical perspective of the UAV testbed development. Lessons learned through the development and use of the testbed over the past several years are summarized.

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Assessing The Quality Of Seawinds Rain Measurements, David G. Long, David W. Draper Jul 2004

Assessing The Quality Of Seawinds Rain Measurements, David G. Long, David W. Draper

Faculty Publications

While SeaWinds was designed to measure ocean winds, it can also measure rain over the ocean. SeaWinds on QuikSCAT active measurements of integrated columnar rain rate obtained via simultaneous wind/rain retrieval are evaluated via Monte Carlo simulation and the Cramer-Rao lower bound on estimate accuracy. Although sufficiently accurate in many conditions, the simultaneous wind/rain retrieval method used with SeaWinds on QuikSCAT data is ill-conditioned for certain wind directions and measurement geometries, sometimes yielding spurious rain rates in zero-rain conditions. To assess the validity of SeaWinds-derived rain rates, a simple empirically based rain thresholding scheme is presented, derived from simulated data. …

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Automatic Detection And Validity Of The Sea-Ice Edge: An Application Of Enhanced-Resolution Quikscat/Seawinds Data, David G. Long, Jorg Haarpaintner, Rasmus T. Tonboe, Michael L. Van Woert Jul 2004

Automatic Detection And Validity Of The Sea-Ice Edge: An Application Of Enhanced-Resolution Quikscat/Seawinds Data, David G. Long, Jorg Haarpaintner, Rasmus T. Tonboe, Michael L. Van Woert

Faculty Publications

Sea-ice edge detection is an essential task at the different national ice services to secure navigation in ice-covered seas. Comparison between the Remund and Long ice mask image from enhanced-resolution QuikScat/SeaWinds (QS) products and the analyzed ice edge from high-resolution RADARSAT synthetic aperture radar has shown that the automatically determined QS ice mask underestimates the Arctic ice extent. QS data was statistically analyzed by colocating the data with ice charts around Greenland and with the National Aeronautics and Space Administration Team's Special Sensor Microwave/Imager (SSM/I) ice concentration algorithm over the whole Arctic region. All variables, i.e., the backscatter in vertical …

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