Environmental Research Institute Of Michigan Research Articles

Mentorship

As I began my career at the Environmental Research Institute of Michigan (ERIM), I was surprised and a bit intimidated when I learned that I would be sharing an office with Juris Upatnieks, who I recognized from my Fourier optics education as one of the pioneers of off-axis holography (along with Emmitt Leith at the University of Michigan). He was a recognizable name in the optics field while I was just a young engineer right out of college, so I thought it was an odd pairing. Fortunately, Juris was a true gentleman with a pleasant and easy-going demeanor, and I quickly became very comfortable in his presence. He was also a skilled experimentalist with a knack for taking ideas sketched out on paper and actually making them work in the laboratory. As the first in a long line of professional colleagues that I consider to be my mentors, he was a positive influence on my laboratory skills while others shaped my analytical, technical writing, project management, and other competencies. Ultimately, I drew a little from each to make me the professional I am today.

Super resolution SAR imaging via parametric spectral estimation methods

Super resolution synthetic aperture radar (SAR) image formation via sophisticated parametric spectral estimation algorithms is considered. Parametric spectral estimation methods are devised based on parametric data models and are used to estimate the model parameters. Since SAR images rather than model parameters are often used in SAR applications, we use the parameter estimates obtained with the parametric methods to simulate data matrices of large dimensions and then use the fast Fourier transform (FFT) methods on them to generate SAR images with super resolution. Experimental examples using the MSTAR and Environmental Research Institute of Michigan (ERIM) data illustrate that robust spectral estimation algorithms can generate SAR images of higher resolution than the conventional FFT methods and enhance the dominant target features.

Environmental Research Institute of Michigan (ERIM)

Environmental Research Institute of Michigan (ERIM)

The ERIM interferometric SAR: IFSARE

The Environmental Research Institute of Michigan (ERIM) and Horizons, Inc. have completed the development, calibration and evaluation of the Advanced Research Projects Agency (ARPA)/US Army Topographic Engineering Center (TEC) funded IFSARE (Interferometric Synthetic Aperture Radar for Digital Terrain Elevations) system. This system rapidly produces geocoded SAR imagery and digital terrain elevation data. The dual-channel, X-band SAR is installed in the ERIM Learjet 36. The ground processor was developed in collaboration with the NASA Jet Propulsion Laboratory. The system produces 1.5 to 3.0 meters (1 sigma) absolute accuracy three-dimensional terrain elevation data over large areas without the use of ground control points. Several examples from recent data collections are presented.

P-3 ultra-wideband SAR: description and examples

Under the Advanced Research Projects Agency (ARPA)/ASTO sponsorship, through a contract from the Naval Air Warfare Center (NAWC), the Environmental Research Institute of Michigan (ERIM) has developed an ultra-wideband (UWB) very high frequency (VHF)/ultrahigh frequency (UHF) fully polarimetric airborne synthetic aperture radar (SAR) for studying the detection of foliage-obscured objects. The radar is installed in the NAWC P-3 testbed aircraft and takes advantage of existing ERIM-built multimode, fully-polarimetric X/L/C-band SAR hardware. This paper describes the radar and presents some examples of its capabilities including polarimetric imagery and two-pass interferometric surface height estimates.

Foliage transmission measurements using a ground-based ultrawide band (300-1300 MHz) SAR system

The attenuation of a forest clearly impacts the ability of airborne SAR systems to image objects within the forest. The level of this attenuation is a function of tree characteristics over the frequency band used in the radar. To experimentally measure the transmission properties of foliage, a bistatic (line-of-site) wide-band system has been built by the Environmental Research Institute of Michigan (ERIM), sponsored by the Air Force's Wright Laboratory, Avionics directorate. This system is polarimetric and can operate coherently over the band from 300 to 1300 MHz. The variation in foliage transmission over the frequency band is important because an imaging radar typically operates coherently over a bandwidth. The system can scan foliage in angle to determine spatial variations in the foliage attenuation. This angular variation in foliage attenuation is quite important because imaging radars typically synthesize an aperture by scanning over a range of angles. The ERIM Wide-Band System is ground-based, with one antenna attached to a carriage which can move 10 m horizontally along an elevated rigid track and the other antenna attached to a fixed tripod. Measurements with the system were conducted during July 1991 at the University of Michigan Biological Field Station in Pellston, MI. The measurements of the mean attenuation as a function of depression angle (15-45/spl deg/) and frequency (300-1300 MHz) of four different forest types are presented. In addition to mean attenuation, the variance in attenuation and the autocorrelation of the attenuation (in angle) are presented. These results imply that the variation of the foliage properties over the bandwidth and scan geometry (or angular variation) will degrade the ability of a radar to focus a foliage obscured object.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Cluster-based segmentation of range images using differential-geometric features

The problem of range image segmentation is considered, and the relative performance of combinations of several differential geometric features such as the orientation and tilt angles of the normal, Gaussian curvature, and mean curvature is evaluated. A very fast and simple histogram-based segmentation scheme for polyhedral objects and reliable segmentation methods based on modified <i>K</i>-means and Unsupervised Fuzzy Partition-Optimum Number of Clusters (UFP-ONC) algorithms are presented. These methods are computationally and implementationally simple, work for both polyhedral and curved objects, are robust enough to deal with noisy features, and perform well without any knowledge of the type and number of objects present. Modifications to the <i>K</i>-means and UFP-ONC algorithms are necessary to deal with periodic features such as the orientation angle of the normal. The combination of orientation angle and mean curvature is shown to produce the best results, and the modified UFP-ONC algorithm is shown to perform better in terms of detecting more meaningful clusters, picking the optimum number of clusters and handling noisy data. Experimental results on range images obtained from the Environmental Research Institute of Michigan illustrate that the proposed methods are effective.

A model-based computer vision system for recognizing handwritten ZIP codes

This paper describes a recognition system for handwritten ZIP Codes currently under development at the Environmental Research Institute of Michigan (ERIM). Included within this system are techniques for preprocessing address block images, locating ZIP Codes, splitting touching characters, and identifying handwritten numerals. These techniques rely on mathematical morphology-based image processing and on hierarchical matching of object models to symbolic image representations. The image processing uses adaptive filtering, thresholding, and skeletonizing to create binary and state-labeled images. The matching process uses these images and extensively developed handwritten digit models to identify ZIP Codes. The end-to-end system has been tested on 500 randomly selected address block images. The system correctly recognized a large portion of the ZIP Codes in the test images (45.0%), and incorrectly classified a very low percentage of isolated handwritten digits (0.9%). Overall performance continues to be improved through incremental digit model refinement.

Book reviews

RAPE OF THE WILD. MAN'S VIOLENCE AGAINST ANIMALS AND THE EARTH, by A. Collard with J. Contrucci, Women's Press, London, 1988, 187 pp. (£5.95) SUSTAINABLE ENVIRONMENTAL MANAGEMENT. PRINCIPLES AND PRACTICE, edited by R. Kerry Turner, Bellhaven Press Boulder, Co; Westview Press, London, 1988, published in association with the Economic and Social Research Council of the UK. (£27.50) THE ECONOMY OF THE EARTH, by M. Sagoff, Cambridge University Press, Cambridge, 1988, 271pp. (£25) ECOLOGY AND DEVELOPMENT IN THE THIRD WORLD, by A. Gupta, Routledge, London and New York, 1988, 80 pp. (£5.95) AIR QUALITY GUIDELINES FOR EUROPE, World Health Organization, Regional Office for Europe, Copenhagen, 1987, 426 pp. (Sw.F. 60) REGIONAL AND LONG RANGE TRANSPORT OF AIR POLLUTION, edited by S. Sandroni, Elsevier, Amsterdam, 1987, 510 pp., index ($170) LAKE ACIDIFICATION IN THE UNITED KINGDOM 1800–1986, Evidence from Analysis of Lake Sediments, by R. W. Batterbee, N. J. Anderson, P. G. Appleby, R. J. Flower, S. C. Fritz, E. Y. Haworth, S. Higgitt, V. J. Jones, A. Kreiser, M. A. R. Munro, J. Natkanski, F. Oldfield, S. T. Patrick, N. G. Richardson, B. Rippey and A. C. Stevenson, Palaeoecology Research Unit, University College London, London WC1H 0AP, 1988, 67 pp. (Prepared for the Department of the Environment and published by ENSIS Publishing, 3 Cintra Park, London SE19 2LH) (£8) ACIDIFICATION IN TROPICAL COUNTRIES SCOPE 36, edited by Henning Rodhe and Rafael Herrera, John Wiley & Sons, Chichester, 1988. 405 pp. (£65, hardback) TOXIC CONTAMINATION IN LARGE LAKES, PROCEEDINGS OF WORLD CONFERENCE ON LARGE LAKES, MACKINAC ‘86. Volume I Chronic Effects of Toxic Contaminants in Large Lakes, 364 pp.; Volume II Impact of Toxic Contaminants on Fisheries Management, 330 pp.; Volume III Sources, Fate, and Controls of Toxic Contaminants, 440 pp.; Volume IV Prevention of Toxic Contamination in Large Lakes, 321 pp.; edited by Norbert W. Schmidtke, Lewis Publishers, Chelsea, USA 1988 (£158.60 for set, hardback) THE PROVIDENT SEA, by D. H. Cushing, Cambridge U.P., Cambridge, 1988, 329 pp. index (£37.50) AIR POLLUTION IN EUROPE, edited by B. Rhode, Vol. I Western Europe. European Coordination Centre for Research and Documentation in the Social Sciences, Vienna, 1988, 193 pp. (no price given) ILL WINDS. AIRBORNE POLLUTION'S TOLL ON TREES AND CROPS, by J. J. Mackenzie and M. T. El‐Ashry, World Resources Institute, Washington D.C., 1988. 74 pp. ($10) THE DARKNESS IS LIGHT ENOUGH, by C. Ferris, Sphere Books, London, 1988, 405 pp. [first published by Michael Joseph, 1986] (£4.50) ENVIRONMENTAL ATLAS FOR BEAUFORT SEA OIL SPILL RESPONSE, by D. Dickins et al., for Environment Canada, D. F. Dickins Associates, Vancouver, 1987, iii + 182 pp. + 61 pp. of appendices (no price given) PEOPLE OF THE TROPICAL RAINFOREST, edited by J. S. Denslow and J. Padoch, University of California Press, Berkeley, Los Angeles and London, in association with Smithsonian Institution Travelling Exhibition Service, Washington, D.C., 1988, 232 pp. (Hardback $35.90; paperback $19.50) RECENT CLIMATIC CHANGE, edited by Stanley Gregory, Belhaven Press, London, 1988, 326 pp. (£33) COASTAL METEOROLOGY, by S‐A. Hsu, Academic Press, Inc., San Diego, Cal., 1988, 260 pp. ($39.50) SATELLITE REMOTE SENSING—AN INTRODUCTION, by Ray Harris, Routledge and Kegan Paul, London and New York, 1987, 220 pp. (£10.95) PROCEEDINGS OF THE TWENTIETH INTERNATIONAL SYMPOSIUM ON REMOTE SENSING OF ENVIRONMENT, 4–10 December 1986 (Nairobi, Kenya), Environmental Research Institute of Michigan, P.O. Box 8618, Ann Arbor, MI 48107–8618, USA, 1987 (no price given) PLANT WATCHING: HOW PLANTS LIVE, FEEL AND WORK, by Malcolm Wilkins, MacMillan, London, 1988, 207 pp. (£14.95) THE SEAWEED HANDBOOK: AN ILLUSTRATED GUIDE TO SEAWEEDS FROM NORTH CAROLINA TO THE ARCTIC, by Thomas F. Lee, Dover Publications Inc., New York, v + 217 pp. 1986, (£4.75) CHESHIRE AND BURN'S MODERN LAW OF REAL PROPERTY, 14th ed., by E. H. Burn, Butterworths, London and Edinburgh, 1988, 974 pp. (£23.95) ELEMENTS OF LAND LAW, by Kevin J. Gray, Butterworths, London, 1987, 1094 pp. (£22.95) ENVIRONMENTAL IMPACT ASSESSMENT AND HIGHWAY PLANNING: A Comparative case study analysis of the United States and the Federal Republic of Germany, by William V. Kennedy, edition sigma, Berlin, 1986, 239 pp. (no price given)

3-D imaging systems and high-speed processing for robot control

Bin picking by a robot in real time requires the performance of a series of tasks that are beyond the capabilities of commercially available state-of-the-art robotic systems. In this paper, a laser-ranging sensor for real-time robot control is described. This sensor is incorporated into a robot system that has been applied to the bin-picking or random-parts problem. This system contains new technological components that have been developed recently at the Environmental Research Institute of Michigan (ERIM). These components (the 3-D imaging scanner and a recirculating cellular-array pipeline processor) make generalized real-time robot vision a practical and viable technology. This paper describes these components and their implementation in a typical real-time robot vision system application.

Neural networks as classifiers of noisy patterns: An experimental comparison with Bayesian classifiers: [formula omitted], Environmental Research Institute of Michigan (ERIM), 1501 Wilson Blvd., Arlington, VA 22209 USA

Neural networks as classifiers of noisy patterns: An experimental comparison with Bayesian classifiers: [formula omitted], Environmental Research Institute of Michigan (ERIM), 1501 Wilson Blvd., Arlington, VA 22209 USA

BOOK REVIEWS

Books reviewed in this article:Satellite Hydrology, Morris Deutsch, Donald R. Wiesnet, and Albert Rango (Editors). American Water Resources Association, Minneapolis, Minnesota. 1981. 730 pages. $85.00.Land Into Water ‐ Water Into Land, Nelson M. Blake. University Presses of Florida, Gainesville, Florida. 1980. 344 pages. $19.95.California Water Planning and Policy: Selected Issues, Ernest Engelbert (Editor). Water Resources Center, University of California. 1979. 252 pages. $5.00.The Infrared Handbook, William Wolfe and George Zissis (Editors). IRIA Center of the Environmental Research Institute of Michigan.Scientific, Technological and Institutional Aspects of Water Resource Policy, Yacov Y. Haimes (Editor). AAAS Selected Symposium 49. Westview Press, Washington, D.C. 1980. 128 pages.Environmental Impact Analysis: A New Dimension in Decision Making (2nd ed.), R. K. Jain, L. V. Urban, and G. S. Stacey. Van Nostrand Reinhold Company, New York, New York. 1981. 393 pages. $27.50.A Policy Approach to Political Representation: Lessons From the Four Comer States, Helen M. Ingram, Nancy K. Laney, and John McCain. A Resources for the Future Book. Johns Hopkins Press. 1981.Water Quality in Catchment Ecosystems, A. M. Gower (Editor). John Wiley and Sons, Somerset, New Jersey. 1980. 335 pages. $50.00.Seepage and Groundwater Flow, K. R. Rushton and S. C. Red‐shaw. John Wiley &amp; Sons, Ltd., Chesire, England. 1979. 339 pages. $45.00.Environmental Biology for Engineers ‐ A Guide to Environmental Assessment, George Camougis. McGraw‐Hill, Inc., New York, New York. 1981. 214 pages. $20.00.

Editorial-The Rudolf Kingslake Medal and Prize, 1979

The winner of the Rudolf Kingslake Medal and Prize for 1979 is Dr. J. R. Fienup of the Environmental Research Institute of Michigan. His award-winning paper on Space Object Imaging through the Turbulent Atmosphere appeared in Optical Engineering 18(5), 529 (1979). This work, begun with his 1975 thesis work at Stanford, developed in several papers prior to this one, and was summarized by him in Optical Engineering 19(3), 297 (1980). Fienup showed that an iterative computer process can reconstruct an object scene from a noisy record of the modulus of its Fourier transform. Since speckle interferometry can be used to derive a diffraction-limited modulus of the Fourier transform, application of Fienup's analysis to the retrieval of diffraction-limited images in speckle interferometry proved quite promising.

Comparison ofin situ and remotely sensed ocean waves off Marineland, Florida

Some early results from an oceanographic experiment staged off Marineland, Florida, in December 1975 are presented, viz., intercomparisons between the X-band and L-band imagery obtained by the Environmental Research Institute of Michigan's (ERIM) dual-wavelength, dualpolarization multiplexed radar. This radar allows direct comparison since the images are produced simultaneously. The wave data obtained from the radar imagery are compared with surface measurements of waves obtained with a pitch- and-roll buoy. The conclusions are only applicable to medium and low wind and wave conditions encountered during the Marineland test. The results indicate that X-band images provide superior quality wave imagery and more useful Fourier Transforms compared to L-band under equivalent signal-to-noise ratios and resolution. Optimum wave imagery is seen when waves propagate in the range direction. Comparisons betweenin situ measurements and X-band imagery of the same area indicate that the dominant wave direction can be obtained from imagery to within a few degrees. A one-dimensional spectrum obtained from X-band imagery compares favorably with an equivalent wave frequency spectrum obtained from the pitch- and-roll buoy after suitable transformation asing linear wave theory.

Near-Infrared Reflectance Anomalies of Andesite and Basalt in Southern California and Nevada

High-reflectivity anomalies in the near infrared (1.0 to 2.6 µm) have been observed on scanner images obtained by the Environmental Research Institute of Michigan (ERIM) in flights over several geologic units in southern California and southwestern Nevada and by the Skylab II mission in flights over western Nevada. These anomalies almost always occur in rocks that are at least as mafic as andesite. The most reasonable explanation for the anomalies is that the anomalous materials have a 5-µm or finer coating of hematite that was formed during cooling and posteruptive fumarolic steaming.