Speckle analysis and smoothing of synthetic aperture radar images

Lee, Jong-Sen

doi:10.1016/s0146-664x(81)80005-6

Cited by 745 publications

(344 citation statements)

References 7 publications

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“…Since the study area is relatively flat, no terrain correction with a digital elevation model was applied. The images were filtered for speckle reduction using the adaptive Lee filter [50] with a 7ˆ7 pixel window size. Geocoding before filtering diminished image artifacts.…”

Section: Sar Data Acquisition and Processingmentioning

confidence: 99%

Mapping Plant Functional Types in Floodplain Wetlands: An Analysis of C-Band Polarimetric SAR Data from RADARSAT-2

et al. 2016

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Abstract:The inclusion of functional approaches on wetland characterizations and on biodiversity assessments improves our understanding of ecosystem functioning. In the Lower Paraná River floodplain, we assessed the ability of C-band polarimetric SAR data of contrasting incidence angles to discriminate wetland areas dominated by different plant functional types (PFTs). Unsupervised H/α and H/A/α Wishart classifications were implemented on two RADARSAT-2 images differing in their incidence angles (FQ24 and FQ08). Obtained classes were assigned to the information classes (open water, bare soil and PFTs) by a priori labeling criteria that involved the expected interaction mechanisms between SAR signal and PFTs as well as the relative values of H and α. The product obtained with the shallow incidence angle scene had a higher accuracy than the one obtained with the steep incidence angle product (61.5% vs. 46.2%). We show how a systematic analysis of the H/A/α space can be used to improve the knowledge about the radar polarimetric response of herbaceous vegetation. The map obtained provides novel ecologically relevant information about plant strategies dominating the floodplain. Since the obtained classes can be interpreted in terms of their functional features, the approach is a valuable tool for predicting vegetation response to floods, anthropic impacts and climate change.

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Section: Sar Data Acquisition and Processingmentioning

confidence: 99%

Mapping Plant Functional Types in Floodplain Wetlands: An Analysis of C-Band Polarimetric SAR Data from RADARSAT-2

et al. 2016

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“…3) image using PolSARpro v4.0 software (Polarimetric SAR Data Processing and Educational Toolbox) (Pottier and Ferro-Famil 2012). A Lee refined filter (Lee, 1981) was then applied to this image using a window of 3*3 pixels to reduce speckle noise. The geocoding process was in this case directly applied to the elements of the 2x2 C 2 matrix which were independent of the polarimetric absolute phase (Lee and Pottier 2009).…”

Section: Pre-processing Of Remote Sensing Datamentioning

confidence: 99%

Assessing ecological habitat structure from local to landscape scales using synthetic aperture radar

Betbeder

Hubert‐Moy

Burel

et al. 2015

Ecological Indicators

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Ecological studies need accurate environmental data such as vegetation characterization, landscape structure and organization, to predict and explain the spatial distribution of biodiversity. Few ecological studies use remote sensing data to assess the biophysical or structural properties of vegetation to understand species distribution. To date, Synthetic Aperture Radar (SAR) data have seldom been used for ecological applications. However, these sensors provide data allowing access to the inner structure of vegetation which is a key information in ecology. The objective of this article is to compare the predictive power of ecological habitat structure variables derived from a TerraSAR-X image, an aerial photograph and a SPOT-5 image for species distribution. The test was run with a hedgerow network in Brittany and assessed the spatial distribution of the forest ground carabid beetles which inhabit these hedgerows. The results confirmed that radar and optical images can be indifferently used to extract hedgerow network and derived landscape metrics (hedgerow density, network grain) useful to explain the spatial distribution of forest carabid beetles. In comparison with passive optical remotely sensed data, VHSR SAR images provide new data to characterize vegetation structure and more particularly hedgerow canopy cover, a variable known to explain the spatial distribution of carabid beetles in an agricultural landscape, but not yet quantified at a fine scale. The hedgerow canopy cover derived from the SAR image is 2 a strong predictor of the abundance of forest carabid beetles at two scales i.e. a local scale and a landscape scale. Keywordsbiodiversity, remote sensing, forest carabid beetles, hedgerow canopy cover, landscape scale, quantitative maps

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“…The LF is based on local statistics [12] proposed by Lee [38], and dealing with the multiplicative noise signal. Many researchers have used the LF for de-speckling in Synthetic Aperture Radar (SAR) images [39,40].…”

Section: Lee Filtermentioning

confidence: 99%

Systematic Evaluation on Speckle Suppression Methods in Examination of Ultrasound Breast Images

2016

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Abstract:Breast ultrasound is an important tool used in the medical treatment and diagnosis of breast tumor. However, noise defined as speckles are generated inevitably. Although the existence of speckle may be beneficial to diagnosis if used by a well-trained observer, it often causes disturbance which negatively affects clinical diagnosis, not only by reducing resolution and contrast of ultrasound images, but also by adding difficulties to recognize tumor region accurately. In this paper, we investigate a number of popular de-speckling algorithms, including filters based on frequency domain, filters based on local statistical properties, filters based on minimum mean square error (MMSE), and filters based on Partial Differential Equation (PDE). Two visual measurement evaluation criteria, i.e., Mean to Variance Ratio (VMR) and Laplace Response of Domain (LRD), are chosen for the performance comparison of those filters in the application of ultrasound breast image filtering. Moreover, the filtering effect is further evaluated with respect to the segmentation accuracy of tumor regions. According to the evaluation results, we conclude that Bilateral Filter (BF) achieves the best visual effect. Although Weickert J Diffusion (WJD) and Total Variation (TV) can also obtain good visual effect and segmentation accuracy, they are very time-consuming.

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Speckle analysis and smoothing of synthetic aperture radar images

Cited by 745 publications

References 7 publications

Mapping Plant Functional Types in Floodplain Wetlands: An Analysis of C-Band Polarimetric SAR Data from RADARSAT-2

Mapping Plant Functional Types in Floodplain Wetlands: An Analysis of C-Band Polarimetric SAR Data from RADARSAT-2

Assessing ecological habitat structure from local to landscape scales using synthetic aperture radar

Systematic Evaluation on Speckle Suppression Methods in Examination of Ultrasound Breast Images

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