M.C. Dobson

University of Michigan–Ann Arbor

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F.T. Ulaby

University of Regina

100

Leland Pierce

University of Michigan–Ann Arbor

L.E. Pierce

University of Michigan–Ann Arbor

Josef Kellndorfer

Woodwell Climate Research Center

Kamal Sarabandi

University of Michigan–Ann Arbor

Kathleen M. Bergen

University of Michigan–Ann Arbor

K. C. McDonald

University of the Sunshine Coast

Eric S. Kasischke

University of Maryland, College Park

J. Way

Newcastle University

Norman L. Christensen

Duke University

Cooperative Institutions

University of Michigan–Ann Arbor

Jet Propulsion Laboratory

University of Kansas

California Institute of Technology

Center for Remote Sensing and Integrated Systems

Michigan United

Centre National de la Recherche Scientifique

Goddard Space Flight Center

US Forest Service

Massachusetts Institute of Technology

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A multi-temporal classifier for SIR-C/X-SAR imagery

Kathleen M. Bergen Leland Pierce M.C. Dobson F.T. Ulaby

Biophysical systems in temperate regions undergo distinct changes in each annual cycle. For forested ecosystems this includes moisture and phenological changes. The dual-flight program (April and October) for the SIR-C/X-SAR instrument aboard the Shuttle Endeavor was designed expressly to acquire imagery at different stages of such cycles. This provides new opportunities in terrain classification where phenology and moisture changes may be used as additional information. Given multi-season SIR-C/X-SAR imagery, there are three possible approaches to classifier development: (1) ignore the multiseason availability and develop independent classifications for each scene using n features, (2) develop one classification for a set of x scenes using n features, with x times the number of samples per feature, and (3) develop a true multi-temporal classification where N of features equals n (number of features) times x (number of scenes). Each of these are applied and results for the first two of six selected scenes show the true multi-temporal and the October scene alone to have the highest accuracies (94% and 95% respectively) at a level II classification.

Contextual image classification

10.1109/igarss.1996.516733

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Mapping regional freeze/thaw patterns with satellite microwave radiometry : annual report for 1990 on NASA grant NAGW-1983

Anthony W. England Brian W. Zuerndorfer John F. Galantowicz M.C. Dobson F.T. Ulaby

Radiometry

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Performance metrics for SAR speckle-suppression filters

Hua Xie F.T. Ulaby L.E. Pierce M.C. Dobson

Because speckle complicates the application of automatic image classification algorithms, several adaptive filters have been proposed for suppressing the speckle while simultaneously preserving the true underlying reflectivity structure of the image. This paper proposes a new set of tools and metrics for evaluating the performance of such filters, and by way of illustration, they are applied to the refined filter introduced by Lee and to the edge-preserving filter introduced by Hagg and Sties.

Speckle noise

10.1109/igarss.1999.772012

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Toward precision forestry: plot-level parameter retrieval for slash pine plantations with jpl airsar

IEEE Transactions on Geoscience and Remote Sensing (2003)

Josef Kellndorfer M.C. Dobson J. Vona Michael L. Clutter

During an EOCAP-SAR project, Airsar P-, L-, and C-band data were used to test the capability of synthetic aperture radar (SAR) to predict biometric parameters which are frequently used by timber managers as inputs to growth, harvest, and yield models. Test site was a commercially managed area in Jesup, southeastern Georgia, with stands owned by Plum Creek Timber Company. A biometric survey data set from 118 cluster plots in two thinned and two unthinned slash pine stands was used to determine the correlation with the Airsar data at the plot level. A statistical model was used to test all possible scenarios of polarimetric and frequency combinations. Using a weighted least squares linear regression model, P/sub HV/ proved to be the single most significant band/polarization combination to correlate with dominant height, basal area, and volume at adjusted squared correlation coefficients of 0.70, 0.80, and 0.84, respectively.

Basal area

Slash Pine

Thinning

10.1109/tgrs.2003.813529

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The effects of vegetation cover on the radar and radiometric sensitivity to soil moisture

International Geoscience and Remote Sensing Symposium (1982)

F.T. Ulaby M.C. Dobson David R. Brunfeldt Mohammad Razani

The measured effects of vegetation canopies on radar and radiometric sensitivity to soil moisture are compared to emission and scattering models. The models are found to predict accurately the measured emission and backscattering for various crop canopies at frequencies between 1.4 and 5.0 GHz, especially at theta equal to or less than 30 deg. Vegetation loss factors, L(theta), increase with frequency and are found to be dependent upon canopy type and water content. In addition, the radiometric power absorption coefficient of a mature corn canopy is 1.75 times that calculated for the radar. Comparison of an L-band radiometer with a C-band radar shows the two systems to be complementary in terms of accurate soil moisture sensing over the extreme range of naturally occurring soil moisture conditions.

Radiometry

Radiometric dating

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SIR-C/X-SAR Mission: Ancillary Data Report

Kathleen M. Bergen M.C. Dobson L.E. Pierce J.R. Kendra Josef Kellndorfer

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Ultra-wideband SAR forest experiment near Raco, Michigan, April 4-12, 1992

M.C. Dobson

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Multiband radar characterization of forest biomes : final report

M.C. Dobson F.T. Ulaby

Biome

Characterization

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Backscattering properties of simulated geological surfaces

J.R. East N. Li F.T. Ulaby M.C. Dobson

A simple, compact, indoor measurement system has been developed to study the radar backscattering properties of a variety of simulated geological surfaces and volumes. The media include a homogeneous layer of fine sand observed for various levels of surface roughness, a sand layer covered with a layer of rocks, and a layer of rocks sandwiched between layers of sand. Four different sizes of rocks were investigated varying from about 1 cm in size to 6 cm in size. The results provide information on the penetration depth of sand, the relative importance of the coherent and incoherent backscattering components, and the magnitude of volume scattering by a layer of rocks relative to surface scattering by a random surface.

Surface layer

Backscatter (email)

Coherent backscattering

Penetration (warfare)

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Forest Information from Synthetic Aperture Radar

Journal of Forestry (2000)

M.C. Dobson

Abstract Radar is often depicted as a promising technology not quite ready for prime time. Data are now becoming available on a routine basis from several existing satellites, but the satellites were not designed for this purpose and--with some exceptions--do not meet the needs of forest inventory and management. The next generation of spaceborne earth-imaging radar promises to change the situation, with multipolarized and high-resolution modes that are much more appropriate for forestry. The principal uses of radar will be to map forest structure and moisture; this information is largely complementary to that obtained by optical techniques.

10.1093/jof/98.6.41

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Citations (22)