Journal articles on the topic 'SAR'
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Czarnocka, Weronika, Yosef Fichman, Maciej Bernacki, Elżbieta Różańska, Izabela Sańko-Sawczenko, Ron Mittler, and Stanisław Karpiński. "FMO1 Is Involved in Excess Light Stress-Induced Signal Transduction and Cell Death Signaling." Cells 9, no. 10 (September 24, 2020): 2163. http://dx.doi.org/10.3390/cells9102163.
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Because of their sessile nature, plants evolved integrated defense and acclimation mechanisms to simultaneously cope with adverse biotic and abiotic conditions. Among these are systemic acquired resistance (SAR) and systemic acquired acclimation (SAA). Growing evidence suggests that SAR and SAA activate similar cellular mechanisms and employ common signaling pathways for the induction of acclimatory and defense responses. It is therefore possible to consider these processes together, rather than separately, as a common systemic acquired acclimation and resistance (SAAR) mechanism. Arabidopsis thaliana flavin-dependent monooxygenase 1 (FMO1) was previously described as a regulator of plant resistance in response to pathogens as an important component of SAR. In the current study, we investigated its role in SAA, induced by a partial exposure of Arabidopsis rosette to local excess light stress. We demonstrate here that FMO1 expression is induced in leaves directly exposed to excess light stress as well as in systemic leaves remaining in low light. We also show that FMO1 is required for the systemic induction of ASCORBATE PEROXIDASE 2 (APX2) and ZINC-FINGER OF ARABIDOPSIS 10 (ZAT10) expression and spread of the reactive oxygen species (ROS) systemic signal in response to a local application of excess light treatment. Additionally, our results demonstrate that FMO1 is involved in the regulation of excess light-triggered systemic cell death, which is under control of LESION SIMULATING DISEASE 1 (LSD1). Our study indicates therefore that FMO1 plays an important role in triggering SAA response, supporting the hypothesis that SAA and SAR are tightly connected and use the same signaling pathways.
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Chen, Junyi, Yanyun Shen, Yinyu Liang, Zhipan Wang, and Qingling Zhang. "YOLO-SAD: An Efficient SAR Aircraft Detection Network." Applied Sciences 14, no. 7 (April 3, 2024): 3025. http://dx.doi.org/10.3390/app14073025.
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Aircraft detection in SAR images of airports remains crucial for continuous ground observation and aviation transportation scheduling in all weather conditions, but low resolution and complex scenes pose unique challenges. Existing methods struggle with accuracy, overlapping detections, and missed targets. We propose You Only Look Once-SAR Aircraft Detector (YOLO-SAD), a novel detector that tackles these issues. YOLO-SAD leverages the Attention-Efficient Layer Aggregation Network-Head (A-ELAN-H) module to prioritize essential features for improved accuracy. Additionally, the SAR Aircraft Detection-Feature Pyramid Network (SAD-FPN) optimizes multi-scale feature fusion, boosting detection speed. Finally, Enhanced Non-Maximum Suppression (EH-NMS) eliminates overlapping detections. On the SAR Aircraft Detection Dataset (SADD), YOLO-SAD achieved 91.9% AP(0.5) and 57.1% AP(0.5:0.95), surpassing the baseline by 2.1% and 1.9%, respectively. Extensive comparisons on SADD further demonstrate YOLO-SAD’s superiority over five state-of-the-art methods in both AP(0.5) and AP(0.5:0.95). The outcomes of further comparative experiments on the SAR-AIRcraft-1.0 dataset confirm the robust generalization capability of YOLO-SAD, demonstrating its potential use in aircraft detection with SAR.
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Gupta, Ashish, Braj Bhushan, and Laxmidhar Behera. "Neural response to sad autobiographical recall and sad music listening post recall reveals distinct brain activation in alpha and gamma bands." PLOS ONE 18, no. 1 (January 6, 2023): e0279814. http://dx.doi.org/10.1371/journal.pone.0279814.
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Although apparently paradoxical, sad music has been effective in coping with sad life experiences. The underpinning brain neural correlates of this are not well explored. We performed Electroencephalography (EEG) source-level analysis for the brain during a sad autobiographical recall (SAR) and upon exposure to sad music. We specifically investigated the Cingulate cortex complex and Parahippocampus (PHC) regions, areas prominently involved in emotion and memory processing. Results show enhanced alpha band lag phase-synchronization in the brain during sad music listening, especially within and between the Posterior cingulate cortex (PCC) and (PHC) compared to SAR. This enhancement was lateralized for alpha1 and alpha2 bands in the left and right hemispheres, respectively. We also observed a significant increase in alpha2 brain current source density (CSD) during sad music listening compared to SAR and baseline resting state in the region of interest (ROI). Brain during SAR condition had enhanced right hemisphere lateralized functional connectivity and CSD in gamma band compared to sad music listening and baseline resting state. Our findings show that the brain during the SAR state had enhanced gamma-band activity, signifying increased content binding capacity. At the same time, the brain is associated with an enhanced alpha band activity while sad music listening, signifying increased content-specific information processing. Thus, the results suggest that the brain’s neural correlates during sad music listening are distinct from the SAR state as well as the baseline resting state and facilitate enhanced content-specific information processing potentially through three-channel neural pathways—(1) by enhancing the network connectivity in the region of interest (ROI), (2) by enhancing local cortical integration of areas in ROI, and (3) by enhancing sustained attention. We argue that enhanced content-specific information processing possibly supports the positive experience during sad music listening post a sad experience in a healthy population. Finally, we propose that sadness has two different characteristics under SAR state and sad music listening.
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Sumarjono, Erry, Agung Dwi Sutrisno, and Denanson Ornansah Sinaga. "DETERMINATION OF THE QUALITY WATER SANGON RIVER THAT EFFECTED BY AMALGAMATION GOLD ORE PROCESSING IN KALIREJO KOKAP DAERAH ISTIMEWA YOGYAKARTA." KURVATEK 7, no. 2 (December 28, 2022): 17–24. http://dx.doi.org/10.33579/krvtk.v7i2.3758.
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Amalgamasi adalah salah satu metode yang dapat digunakan untuk ekstraksi emas dengan menggunakan merkuri. Merkuri merupakan logam berat yang sangat berbahaya bagi kesehatan manusia. Pembuangan limbah pengolahan bijih emas dengan menggunakan metode amalgamasi yang masih mengandung merkuri ke sungai dapat mempengaruhi kualitas air sungai tersebut. Penelitian yang dilakukan di Sungai Sangon untuk mengukur kandungan merkuri di dalam air sungai tersebut dan menentukan status mutu air sungai tersebut berdasarkan baku mutu air dalam Peraturan Pemerintah No. 82 Tahun 2001. Pengambilan sampel dilakukan di sepanjang aliran sungai pada titik SA1, SA2, SA3, SA4, SA5 dan SA6. Pengukuran kandungan merkuri dilakukan uji laboratorium dengan menggunakan metode Mercury Analyzer, LPPT Universitas Gadjah Mada. Hasil uji laboratorium menunjukkan bahwa kandungan merkuri di dalam air sungai Sangon masih jauh berada di bawah ambang batas yang ditentukan, sehingga masih aman digunakan untuk keperluan sesuai peruntukkan mutu air kela
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Khamseh, Amir. "On Generalized Schur Numbers of the Equation x+ay=z." Journal of Mathematics 2020 (May 31, 2020): 1–5. http://dx.doi.org/10.1155/2020/7069730.
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Let a and r be positive integers. By definition, sar is the least positive integer such that, for any r-coloring of the interval 1,sar, there exists a monochromatic solution to x+ay=z. For a=1, the numbers sr=s1r are classical Schur numbers. In this paper, we study the numbers sar for a≥2.
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Xun, Pengwei, Chuanpeng Zhou, Xiaolin Huang, Zhong Huang, Wei Yu, Yukai Yang, Tao Li, Jianbin Huang, Yang Wu, and Heizhao Lin. "Effects of Dietary Sodium Acetate on Growth Performance, Fillet Quality, Plasma Biochemistry, and Immune Function of Juvenile Golden Pompano (Trachinotus ovatus)." Aquaculture Nutrition 2022 (February 9, 2022): 1–11. http://dx.doi.org/10.1155/2022/9074549.
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Six isonitrongenous and isolipidic diets were formulated to feed 360 fish (mean initial body weight: 6.06 ± 0.02 g) with graded levels of sodium acetate (SA1 (0), SA2 (250 mg/kg), SA3 (500 mg/kg), SA4 (1000 mg/kg), SA5 (2000 mg/kg), and SA6 (4000 mg/kg)) for 8 weeks. The results revealed that weight gain rate, specific growth rate, and feed intake of golden pompano were significantly increased in SA3 and SA4 treatments ( p < 0.05 ). Dietary SA level significantly improved lipid contents and gumminess of muscle ( p < 0.05 ). Supplement levels of dietary SA significantly influenced plasma biochemical parameters containing triglyceride, glucose, high-density lipoprotein cholesterol, complements, and immunoglobulin M ( p < 0.05 ). Appropriate supplement levels of dietary SA significantly increased enzyme activities of hepatic superoxide dismutase and total antioxidant capacity and decreased malondialdehyde contents ( p < 0.05 ). Furthermore, appropriate SA levels downregulated the expression levels of Keap1, IL-8, TNF-α, and NF-κB genes and upregulated the expression levels of Nrf2 and TGF-β genes of the spleen ( p < 0.05 ). Excess SA caused negative effects for Trachinotus ovatus. The optimum supplement level of SA for juvenile golden pompano was evaluated to be 1423.67 mg/kg based on WGR.
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Gao, Fei, Wei Shi, Jun Wang, Erfu Yang, and Huiyu Zhou. "Enhanced Feature Extraction for Ship Detection from Multi-Resolution and Multi-Scene Synthetic Aperture Radar (SAR) Images." Remote Sensing 11, no. 22 (November 18, 2019): 2694. http://dx.doi.org/10.3390/rs11222694.
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Independent of daylight and weather conditions, synthetic aperture radar (SAR) images have been widely used for ship monitoring. The traditional methods for SAR ship detection are highly dependent on the statistical models of sea clutter or some predefined thresholds, and generally require a multi-step operation, which results in time-consuming and less robust ship detection. Recently, deep learning algorithms have found wide applications in ship detection from SAR images. However, due to the multi-resolution imaging mode and complex background, it is hard for the network to extract representative SAR target features, which limits the ship detection performance. In order to enhance the feature extraction ability of the network, three improvement techniques have been developed. Firstly, multi-level sparse optimization of SAR image is carried out to handle clutters and sidelobes so as to enhance the discrimination of the features of SAR images. Secondly, we hereby propose a novel split convolution block (SCB) to enhance the feature representation of small targets, which divides the SAR images into smaller sub-images as the input of the network. Finally, a spatial attention block (SAB) is embedded in the feature pyramid network (FPN) to reduce the loss of spatial information, during the dimensionality reduction process. In this paper, experiments on the multi-resolution SAR images of GaoFen-3 and Sentinel-1 under complex backgrounds are carried out and the results verify the effectiveness of SCB and SAB. The comparison results also show that the proposed method is superior to several state-of-the-art object detection algorithms.
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Uknes, S., T. Delaney, B. Vernooij, L. Friedrich, S. Williams, D. Chandler, K. Weymann, et al. "1007 SYSTEMIC ACQUIRED RESISTANCE." HortScience 29, no. 5 (May 1994): 573g—574. http://dx.doi.org/10.21273/hortsci.29.5.573g.
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Systemic acquired resistance is a broad spectrum inducible defense response that is associated with the expression of a set of genes (SAR genes). Expression of one of these genes (PR-1a from tobacco) in transgenic tobacco confers increased tolerance to two oomycete pathogens. A direct role for salicylic acid (SA) in signaling SAR has been established in tobacco by analysis of transgenic tobacco expressing salicylate hydroxylase (SAH, an enzyme that inactivates SA by conversion to catechol). Tobacco plants that express SAH are blocked in the accumulation of SA and the development of SAR when responding lo TMV. Furthermore, both Arabidopsis and tobacco expressing SAH have altered pathogen induced lesion morphology, exemplified by larger spreading lesions. Putative mutants in SAR gene expression were isolated by screening M2 Arabidopsis plants for altered expression of PR-1 and PR-2 or for sensitivity to pathogen infection following INA treatment. The putative mutants all into two major classes,constitutive (cim, constitutive immunity) and non-inducible (nim, non-inducible immunity). Several cim mutants exhibits a disease lesion phenotype in the absence of pathogen.
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IRIE, HARUYUKI, and KEI TOKITA. "SPECIES-AREA RELATIONSHIP FOR POWER-LAW SPECIES ABUNDANCE DISTRIBUTION." International Journal of Biomathematics 05, no. 03 (May 2012): 1260014. http://dx.doi.org/10.1142/s1793524512600145.
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We studied the mathematical relations between species abundance distributions (SADs) and species-area relationships (SARs) and found that a power-law SAR can be generally derived from a power-law SAD without a special assumption such as the "canonical hypothesis". In the present analysis, an SAR-exponent is obtained as a function of an SAD-exponent for a finite number of species. We also studied the inverse problem, from SARs to SADs, and found that a power-SAD can be derived from a power-SAR under the condition that the functional form of the corresponding SAD is invariant for changes in the number of species. We also discuss general relationships among lognormal SADs, the broken-stick model (exponential SADs), linear SARs and logarithmic SARs. These results suggest the existence of a common mechanism for SADs and SARs, which could prove a useful tool for theoretical and experimental studies on biodiversity and species coexistence.
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Li, Yu, Yuanzhi Zhang, Zifeng Yuan, Huaqiu Guo, Hongyuan Pan, and Jingjing Guo. "Marine Oil Spill Detection Based on the Comprehensive Use of Polarimetric SAR Data." Sustainability 10, no. 12 (November 26, 2018): 4408. http://dx.doi.org/10.3390/su10124408.
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As a major marine pollution source, oil spills largely threaten the sustainability of the coastal environment. Polarimetric synthetic aperture radar remote sensing has become a promising approach for marine oil spill detection since it could effectively separate crude oil and biogenic look-alikes. However, on the sea surface, the signal to noise ratio of Synthetic Aperture Radar (SAR) backscatter is usually low, especially for cross-polarized channels. In practice, it is necessary to combine the refined detail of slick-sea boundary derived from the co-polarized channel and the highly accurate crude slick/look-alike classification result obtained based on the polarimetric information. In this paper, the architecture for oil spill detection based on polarimetric SAR is proposed and analyzed. The performance of different polarimetric SAR filters for oil spill classification are compared. Polarimetric SAR features are extracted and taken as the input of Staked Auto Encoder (SAE) to achieve high accurate classification between crude oil, biogenic slicks, and clean sea surface. A post-processing method is proposed to combine the classification result derived from SAE and the refined boundary derived from VV channel power image based on special density thresholding (SDT). Experiments were conducted on spaceborne fully polarimetric SAR images where both crude oil and biogenic slicks were presented on the sea surface.
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Antunes, Maria, Custódia Gago, Adriana Guerreiro, Ana Sousa, Miriam Julião, Maria Miguel, Maria Faleiro, and Thomas Panagopoulos. "Nutritional Characterization and Storage Ability of Salicornia ramosissima and Sarcocornia perennis for Fresh Vegetable Salads." Horticulturae 7, no. 1 (January 8, 2021): 6. http://dx.doi.org/10.3390/horticulturae7010006.
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The aim of this work was to study the potential of two halophytes for fresh salads. Sarcocornia perennis (SAR) and Salicornia ramosissima (SAL) plant tips were harvested in May and July, and stored at 4 °C for 14 days. At harvest, mineral analyses (Na, K, Mg, Ca, P, N, Fe, Zn, Cu, Pb and Cd), chlorophyll content, protein, β-carotene and ascorbic acid were performed. Color (CIELab), phenolics, antioxidant activity and microbial contamination were measured at harvest and after 14 days storage at 4 °C, and a taste panel evaluated the products. SAL had generally slightly higher values of vitamin C, phenols and carotenoids than SAR. In SAR after 14 days of storage, the levels of phenols and the antioxidant activity were higher than at harvest, both in May and July. The opposite was observed for SAL. In this case, only the antioxidant activity was higher after 14 days of storage. Microbial contamination was very low, not reaching even half of critical limits. Both halophytes had good nutritional value, being suitable for use as fresh salads which can be stored for up to 14 days at 4 °C. SAR seems to be a better source of antioxidants, Ca and Fe than SAL and has less general quality and nutritional value changes from harvest time through cold storage. Fresh tips of both halophytes showed better appearance and nutritional quality when harvested in the early season (May) than at the end of the season (July).
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Antunes, Maria Dulce, Custódia Gago, Adriana Guerreiro, Ana Rita Sousa, Miriam Julião, Maria Graça Miguel, Maria Leonor Faleiro, and Thomas Panagopoulos. "Nutritional Characterization and Storage Ability of Salicornia ramosissima and Sarcocornia perennis for Fresh Vegetable Salads." Horticulturae 7, no. 1 (January 8, 2021): 6. http://dx.doi.org/10.3390/horticulturae7010006.
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The aim of this work was to study the potential of two halophytes for fresh salads. Sarcocornia perennis (SAR) and Salicornia ramosissima (SAL) plant tips were harvested in May and July, and stored at 4 °C for 14 days. At harvest, mineral analyses (Na, K, Mg, Ca, P, N, Fe, Zn, Cu, Pb and Cd), chlorophyll content, protein, β-carotene and ascorbic acid were performed. Color (CIELab), phenolics, antioxidant activity and microbial contamination were measured at harvest and after 14 days storage at 4 °C, and a taste panel evaluated the products. SAL had generally slightly higher values of vitamin C, phenols and carotenoids than SAR. In SAR after 14 days of storage, the levels of phenols and the antioxidant activity were higher than at harvest, both in May and July. The opposite was observed for SAL. In this case, only the antioxidant activity was higher after 14 days of storage. Microbial contamination was very low, not reaching even half of critical limits. Both halophytes had good nutritional value, being suitable for use as fresh salads which can be stored for up to 14 days at 4 °C. SAR seems to be a better source of antioxidants, Ca and Fe than SAL and has less general quality and nutritional value changes from harvest time through cold storage. Fresh tips of both halophytes showed better appearance and nutritional quality when harvested in the early season (May) than at the end of the season (July).
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Kipp, Michael, Frank Göhring, Thorsten Ostendorp, Cornelis M. van Drunen, Roel van Driel, Michael Przybylski, and Frank O. Fackelmayer. "SAF-Box, a Conserved Protein Domain That Specifically Recognizes Scaffold Attachment Region DNA." Molecular and Cellular Biology 20, no. 20 (October 15, 2000): 7480–89. http://dx.doi.org/10.1128/mcb.20.20.7480-7489.2000.
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ABSTRACT SARs (scaffold attachment regions) are candidate DNA elements for partitioning eukaryotic genomes into independent chromatin loops by attaching DNA to proteins of a nuclear scaffold or matrix. The interaction of SARs with the nuclear scaffold is evolutionarily conserved and appears to be due to specific DNA binding proteins that recognize SARs by a mechanism not yet understood. We describe a novel, evolutionarily conserved protein domain that specifically binds to SARs but is not related to SAR binding motifs of other proteins. This domain was first identified in human scaffold attachment factor A (SAF-A) and was thus designated SAF-Box. The SAF-Box is present in many different proteins ranging from yeast to human in origin and appears to be structurally related to a homeodomain. We show here that SAF-Boxes from four different origins, as well as a synthetic SAF-Box peptide, bind to natural and artificial SARs with high specificity. Specific SAR binding of the novel domain is achieved by an unusual mass binding mode, is sensitive to distamycin but not to chromomycin, and displays a clear preference for long DNA fragments. This is the first characterization of a specific SAR binding domain that is conserved throughout evolution and has DNA binding properties that closely resemble that of the unfractionated nuclear scaffold.
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Chen, Mingmin, Anurag Singh, Fang Xiao, Ulrike Dringenberg, Jian Wang, Regina Engelhardt, Sunil Yeruva, et al. "Gene ablation for PEPT1 in mice abolishes the effects of dipeptides on small intestinal fluid absorption, short-circuit current, and intracellular pH." American Journal of Physiology-Gastrointestinal and Liver Physiology 299, no. 1 (July 2010): G265—G274. http://dx.doi.org/10.1152/ajpgi.00055.2010.
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PEPT1 function in mouse intestine has not been assessed by means of electrophysiology and methods to assess its role in intracellular pH and fluid homeostasis. Therefore, the effects of the dipeptide glycilsarcosin (Gly-Sar) on jejunal fluid absorption and villous enterocyte intracellular pH (pHi) in vivo, as well as on enterocyte[14C]Gly-Sar uptake, short-circuit current ( Isc) response, and enterocyte pHi in vitro were determined in wild-type and PEPT1-deficient mice and in mice lacking PEPT1. Immunohistochemistry for PEPT1 failed to detect any protein in enterocyte apical membranes in Slc15a1−/− animals. Saturable Gly-Sar uptake in Slc15a1−/− everted sac preparations was no longer detectable. Similarly, Gly-Sar-induced jejunal Isc response in vitro was abolished. The dipeptide-induced increase in fluid absorption in vivo was also abolished in animals lacking PEPT1. Since PEPT1 acts as an acid loader in enterocytes, enterocyte pHi was measured in vivo by two-photon microscopy in SNARF-4-loaded villous enterocytes of exteriorized jejuni in anesthetized mice, as well as in BCECF-loaded enterocytes of microdissected jejunal villi. Gly-Sar-induced pHi decrease was no longer observed in the absence of PEPT1. A reversal of the proton gradient across the luminal membrane did not significantly diminish Gly-Sar-induced Isc response, whereas a depolarization of the apical membrane potential by high K+ or via Na+-K+-ATPase inhibition strongly diminished Gly-Sar-induced Isc responses. This study demonstrates for the first time that proton-coupled electrogenic dipeptide uptake in the native small intestine, mediated by PEPT1, relies on the negative apical membrane potential as the major driving force and contributes significantly to intestinal fluid transport.
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Xia, Weijie, Yuanyuan Qi, Linlin Huang, and Xue Jin. "Missile-Borne SAR Raw Signal Simulation for Maneuvering Target." International Journal of Antennas and Propagation 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/2598024.
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SAR raw signal simulation under the case of maneuver and high-speed has been a challenging and urgent work recently. In this paper, a new method based on one-dimensional fast Fourier transform (1DFFT) algorithm is presented for raw signal simulation of maneuvering target for missile-borne SAR. Firstly, SAR time-domain raw signal model is given and an effective Range Frequency Azimuth Time (RFAT) algorithm based on 1DFFT is derived. In this algorithm, the “Stop and Go” (SaG) model is adopted and the wide radar scattering characteristic of target is taken into account. Furthermore, the “Inner Pulse Motion” (IPM) model is employed to deal with high-speed case. This new RFAT method can handle the maneuvering cases, high-speed cases, and bistatic radar cases, which are all possible in the missile-borne SAR. Besides, this raw signal simulation adopts the electromagnetic scattering calculation so that we do not need a scattering rate distribution map as the simulation input. Thus, the multiple electromagnetic reflections can be considered. Simulation examples prove the effectiveness of our method.
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Minami, H., H. Daniel, E. L. Morse, and S. A. Adibi. "Oligopeptides: mechanism of renal clearance depends on molecular structure." American Journal of Physiology-Renal Physiology 263, no. 1 (July 1, 1992): F109—F115. http://dx.doi.org/10.1152/ajprenal.1992.263.1.f109.
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We have investigated the relative contribution of hydrolysis, intact transport and urinary excretion to the renal clearance of Gly-Sar, Gly-Sar-Sar, and Gly-Gly-Sar in fed and starved rats. The results obtained from isolated kidney perfusion studies are summarized as follows: 1) clearance was fastest for Gly-Gly-Sar and slowest for Gly-Sar-Sar, 2) urinary excretion of Gly-Sar-Sar exceeded that of Gly-Gly-Sar or Gly-Sar, 3) there was accumulation of products of hydrolysis of Gly-Gly-Sar in the perfusate but not of Gly-Sar or Gly-Sar-Sar, 4) isolated brush-border and basolateral membranes of renal tubular cells lacked hydrolytic activity against Gly-Sar and Gly-Sar-Sar but possessed hydrolytic activity against Gly-Gly-Sar, 5) an excess amount of Gly-Sar-Sar reduced the rate of clearance of Gly-Gly-Sar by approximately 40% and significantly increased urinary excretion of this peptide, 6) the nonfiltering kidney cleared Gly-Gly-Sar at a rate which was 50% of that of the filtering kidney but did not clear Gly-Sar, and 7) starvation for 96 h was without a significant effect on the renal clearance of either Gly-Sar or Gly-Sar-Sar but significantly reduced the renal clearance of Gly-Gly-Sar and the brush-border membrane hydrolase activity against this peptide. We conclude that the molecular structure determines the affinity of oligopeptides for the membrane transport and hydrolytic systems, which, in turn, determines their efficiency for clearance by the kidney.
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Machado, Leandro S., Felipe F. dos Santos, Lídia M. M. dos Santos, Rogério Tortelly, Jorge C. Pimentel, Luiz Sesti, Virgínia L. A. Pereira, and Elmiro R. Nascimento. "Transmission, serologic and tissue responses in chickens vaccinated with Mycoplasma gallisepticum F strain (MG-F)." Pesquisa Veterinária Brasileira 36, no. 5 (May 2016): 401–4. http://dx.doi.org/10.1590/s0100-736x2016000500008.
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Abstract: MG-F protects chickens from MG Mycoplasmosis and monitoring is done by serology (SAR and ELISA) and PCR. Histopathology is used to evaluate bird response to MG. This study evaluated MG-F profile vaccination in SPF chicken. This trial used 100 chickens, being 40 unvaccinated (G1), 40 eye-drop vaccinated at 8 weeks of age with MG-F ( Ceva Animal Health , São Paulo , SP , Brazil ) (G2) and 20 immunized by contact (G3) . Samples were obtained on the 8th, 12th, 15th, 18th, 20th and 24th week for SAR, ELISA and PCR. Fragments of trachea and air sac, for microscopy, were got after necropsies on the 15th and 24th week. Up to 12 weeks there was no significant difference among groups by SAR. SAR reactions appeared from the 15th week with these averages: G1 (1.7, 1.76 , 0.1, 0.15) , G2 (7.81, 7.65, 8.25, 6.29) and G3 (8.1, 8.5, 9.5, 6.16), while by ELISA it occurred after the 18th week with optical densities averages: G1 (0.19, 0.14, 0.16) , G2 (0.47, 0.45, 0.41) and G3 (0.55, 0.51, 0.51) . Positivity in G3 by PCR occurred seven weeks after exposure. At the 15th week the air sac score means were 0.20, 0.55, and 0.32 and 24th week were 0.15, 0.80 and 0.66 (p>0.05). For trachea, G2 (0.48) yielded higher score average than G1 (0.10) and G3 (0.00) on the 15th week. Changes in G3 were seen only at 24th week, being this average (1.00) significantly different (p<0,05) from G1 (0.08) and G2 (0.46). SAR and PCR detected MG-F in G3 earlier than ELISA. Higher tracheal changes for G2 and G3 as compared to G1 could be ascribed to MG-F vaccine infection.
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Abdi, Mukhlis, Idiannor Mahyudin, Fadly H. Yusran, and Achmad Syamsu Hidayat. "EFEKTIVITAS METODE COVERING DALAM PENGELOLAN AIR ASAM TAMBANG DI PT. BINUANG MITRA BERSAMA BLOK DUA, KABUPATEN TAPIN, KALIMANTAN SELATAN." EnviroScienteae 18, no. 1 (April 26, 2022): 1. http://dx.doi.org/10.20527/es.v18i1.12973.
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The formation of AMW is basically unavoidable in mining activities, AMW can be formed in pit and disposal area that are contaminated with potential acid forming material (PAF). The magnitude of the potential impact that AMW can have on mining activities certainly encourages every business actor to conduct a study on various preventive measures that are effectively implemented in AMW management, one of which is covering method. This thesis research aims to analyze the preventive covering method in the management of AMW and its effectiveness in meeting quality standards of liquid waste in coal mining activities. The Object of research is surface water that is in contact with covering treatment area (soil) which is also given additional treatment by planting cover crops and pioneer plants at OPD Sitarum. Surface water quality was tested in the laboratory with reference to BMLC standard of South Kalimantan Governor Regulation Number 36 of 2008. The results of the laboratory tests were then calculated for effectiveness and proved statistical analysis using normality test, homogeneity test, CRD test and DMRT to be able to conclude the effect of covering treatment in the management of AMW. The results showed that the application of covering method in OPD Sitarum was able to have a positive and significant effect on improving surface water quality. Where based on the results of laboratory tests, the SA4 and SA5 treatments have met the BMLC standard of the South Kalimantan Governor Regulation Number 36 of 2008. The laboratory results are strengthened by statistical data which shows that all treatment data are normally distributed and homogeneous, the results of CRD and DMRT analysis show the parameters of pH, TSS, and total-Fe was significantly different between SA2, SA3, SA4, and SA5 treatments against SA1 (control). Meanwhile, total-Mn parameter stated that SA2 and SA3 were not significantly different from the control, SA4 and SA5 were significantly different from the control. And for Cadmium (Cd) parameter, all treatments (SA2, SA3, SA4, and SA5) were not significantly different from the control. The conclusion of this research, the covering method applied in OPD Sitarum is considered effective in the management of AMW in a preventive manner. This is proven in SA4 treatment (covering + cover crop + Pioneer 1-2 years), where the results of the surface water quality test have met the BMLC standards of the South Kalimantan Governor Regulation Number 36 of 2008 with values: pH 6.95; TSS 159 mg L -1 ; total-Fe 1.93 mg L-1 ; total-Mn 0.031 mg L-1 ; and Cd 0.0045 mg L-1 . And the best covering treatment and effectiveness were found in SA5 treatment (covering + cover crop + 3-4 years pioneer plant) with values: pH 6.67; TSS 76.5 mg L-1 (97.22%); totalFe 1.13 mg L-1 (88.71%); total-Mn 0.019 mg L-1 (87.58%); and Cd 0.0058 mg L-1 (8.00%).
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Mamat, Rabiei, Tutut Herawan, and Mustafa Mat Deris. "SAR." International Journal of Information Retrieval Research 1, no. 4 (October 2011): 38–52. http://dx.doi.org/10.4018/ijirr.2011100103.
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Soft-set theory proposed by Molodstov is a general mathematic tool for dealing with uncertainty. Recently, several algorithms have been proposed for decision making using soft-set theory. However, these algorithms still concern on Boolean-valued information system. In this paper, Support Attribute Representative (SAR), a soft-set based technique for decision making in categorical-valued information system is proposed. The proposed technique has been tested on three datasets to select the best partitioning attribute. Furthermore, two UCI benchmark datasets are used to elaborate the performance of the proposed technique in term of executing time. On these two datasets, it is shown that SAR outperforms three rough set-based techniques TR, MMR, and MDA up to 95% and 50%, respectively. The results of this research will provide useful information for decision makers to handle categorical datasets.
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An, Nguyễn Hùng, and Nguyễn Tiến Phát. "A COMBINATION OF NEIGHBORHOOD BASED RATIO OPERATOR AND CONVOLUTIONAL WAVELET NEURAL NETWORKS FOR CHANGE DETECTION IN MULTI-TEMPORAL SYNTHETIC APERTURE RADAR IMAGES." TNU Journal of Science and Technology 226, no. 06 (May 31, 2021): 97–104. http://dx.doi.org/10.34238/tnu-jst.4476.
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Phát hiện sự thay đổi trong ảnh SAR đa thời gian được ứng dụng rộng rãi trong các ứng dụng thực tế về hoạt động quản lý kiểm tra, giám sát tài nguyên trên đất liền và trên biển với quy mô rộng lớn. Có rất nhiều thuật toán phát hiện sự thay đổi sử dụng hai ảnh SAR đa thời gian. Nguyên tắc phổ biến của chúng là thực hiện phân tích ảnh sai khác được tạo ra từ toán tử tỷ số của hai ảnh SAR đa thời gian nhằm phát hiện các sự thay đổi giữa chúng. Để cải thiện độ chính xác phát hiện, toán tử tỷ số và các phiên bản cải tiến của toán tử này thường được sử dụng kết hợp với các phương pháp xử lý tinh hơn nữa. Bài báo này đề xuất một giải pháp phát hiện sự thay đổi bằng cách kết hợp toán tỷ số dựa trên lân cận và thuật toán mạng nơ ron wavelet tích chập để cải thiện độ chính xác phát hiện sự thay đổi trong ảnh SAR đa thời gian.
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Lee, In-Hyeok, Kyung-Min Lee, Min-Gon Cho, Young-Ju Park, Sang-Won Kim, and Kyung-Tae Kim. "SAR Noise Jamming Performance Evaluation Using SAR-ATR." Journal of Korean Institute of Electromagnetic Engineering and Science 34, no. 7 (July 2023): 581–90. http://dx.doi.org/10.5515/kjkiees.2023.34.7.581.
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Zhou, Fan, Hua Chen, and Peng Zhang. "Performance Evaluation of Maritime Search and Rescue Missions Using Automatic Identification System Data." Journal of Navigation 73, no. 6 (May 19, 2020): 1237–46. http://dx.doi.org/10.1017/s0373463320000223.
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In maritime search and rescue (SAR), commanders need to understand the task execution efficiency of each SAR unit in real time to improve the overall efficiency of SAR efforts. This study proposes a method to evaluate the progress of maritime SAR missions using automatic identification system (AIS) data. First, the positioning accuracy of the AIS data was improved according to the relationship between position, speed, and course. Second, the historical track of the SAR ship was used to generate the SAR completion area based on a line buffer algorithm. The SAR completion area and SAR mission area were then superimposed to determine the overall progress of the SAR mission. The proposed method has been deployed within the SAR software on-board Haixun01 (China's largest and most advanced large-scale cruise rescue ship) since 2017 and has played an important role in devising SAR strategies and tracking mission progress, during several SAR actions.
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Elgamel, Sherif A., and Mohamed Samir Abdel-Latif. "Synthetic Aperture Radar Active Decoy." Advances in Military Technology 17, no. 1 (April 5, 2022): 47–62. http://dx.doi.org/10.3849/aimt.01520.
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Synthetic aperture radar (SAR) has been widely involved in military reconnaissance and detection of moving targets. SAR active decoy can generate deceptive jamming signal and it can severely affect the content of SAR focused image. SAR range Doppler algorithm (RDA) is considered as one of the most common algorithms utilized in the image formation processor (IFP) in SAR sensors. In this paper, the inverse RDA (IRDA) deception jamming technique and its evaluation criteria on SAR are demonstrated. Mathematical formulations for SAR RDA with and without deception jamming are presented. Matlab simulation and results of SAR RDA under the proposed deception scenario are discussed. SAR point target simulation of the proposed deceptive jamming and false target insertion into real large scene are also introduced. Comparison of the proposed deceptive jamming to signal power ratio (JSR) required to counter SAR with other SAR jamming techniques is analyzed.
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Song, Lihao, Bowen Bai, Xiaoping Li, Gezhao Niu, Yanming Liu, Liang Zhao, and Hui Zhou. "Analysis of Hypersonic Platform-Borne SAR Imaging: A Physical Perspective." Remote Sensing 13, no. 23 (December 5, 2021): 4943. http://dx.doi.org/10.3390/rs13234943.
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The usage of a hypersonic platform for remote sensing application has promising prospects, especially for hypersonic platform-borne synthetic aperture radar (SAR) imaging. However, the high-speed of hypersonic platform will lead to extreme friction between the platform and air, which will cause the ionization of air. The ionized gas forms the plasma sheath wrapped around the hypersonic platform. The plasma sheath will severely affect the propagation of SAR signal and further affect the SAR imaging. Therefore, hypersonic platform-borne SAR imaging should be studied from a physical perspective. In this paper, hypersonic platform-borne SAR imaging under plasma sheath is analyzed. The SAR signal propagation in plasma sheath is computed using scatter matrix method. The proposed SAR signal model is verified by using a ground experiment system. Moreover, the effect of attenuation caused by plasma sheath on SAR imaging is studied under different SAR parameters and plasma sheath. The result shows that attenuation caused by plasma sheath will degrade the SAR imaging quality and even cause the point and area targets to be submerged into the noise. The real SAR images under plasma sheath also illustrate this phenomenon. Furthermore, by studying imaging results under different SAR and plasma parameters, it can be concluded that the severe degradation of SAR imaging quality appears at condition of high plasma sheath electron density and low SAR carrier frequency. The work in this paper will be beneficial for the study of hypersonic platform-borne SAR imaging and design of hypersonic SAR imaging systems in the future.
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Kang, Young-Geun, Chul-Ki Kim, and Seong-Ook Park. "Ocean Image Formation Algorithm Using Altimeter Data for Next Generation Satellite SAR." Journal of Electromagnetic Engineering and Science 22, no. 2 (March 31, 2022): 85–94. http://dx.doi.org/10.26866/jees.2022.2.r.64.
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Synthetic aperture radar (SAR) obtains two-dimensional images of the Earth’s surface. Spatial resolution is one of the most important factors in evaluating SAR performance. Therefore, high operating frequencies are preferred for obtaining high resolution images. In fact, Ku-band and Ka-band are used in the automobile SAR (Auto-SAR) and the aircraft SAR (Airborne-SAR). However, the operating frequencies of the satellite SAR (Spaceborne-SAR) are limited to the X-band because of the wide Doppler frequency band caused by the satellite’s high velocity. To overcome this frequency limitation in satellite SAR, we propose a low-complexity SAR algorithm that forms images of the ocean using satellite altimeter data with an operating frequency of the Ku-band (13.575 GHz). The algorithm requires the burst mode pulse transmission technique frequently used in SAR altimeters. To validate the proposed algorithm as being suitable for ocean image formation, point target simulation and analysis are performed, and some quantitative results are provided.
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Awujoola, Olalekan J., PO Odion, AE Evwiekpaefe, and GN Obunadike. "Multi-Class Dual- Stream Convolutional Neural Network for Synthetic Aperture Radar Automatic Target Recognition of Ground Military Vehicle." Journal of Scientific Research 66, no. 04 (2022): 107–13. http://dx.doi.org/10.37398/jsr.2022.660415.
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Synthetic Aperture Radar (SAR) target classification is one of the largest branches of SAR image analysis. Despite the remarkable achievements of deep learning-based SAR target prediction algorithms, current object recognition algorithms are limited in terms of military applications. Acquisition and labeling of SAR target images are time-consuming and cumbersome. Obtaining adequate training data is also challenging in many cases. Deep learning-based models are always susceptible to overfitting because of insufficient training data. This limitation prevents them from being widely used to classify SAR targets. To overcome the problem of insufficient sampling and to learn more accurate representations for SAR image recognition, we propose a two way input of SAR images into a dual stream of DCNN. Concatenating two input SAR images representations was done using the restricted raw SAR data in order to extract the integral features from the 2 input SAR images representations for classification. The proposed methodology addressed the problem of insufficient sample in SAR target classification and improved classification accuracy without overfitting. Experimental results confirmed that the proposed method is effective in addressing the problem of insufficient sample in SAR target classification. This technique can be integrated into any SAR classification model based on convolutional neural networks (CNNs). The model MCDS-CNN results in a 99.1% recognition accuracy. Despite the limited availability of SAR image data from MSTAR, this approach provides good recognition results.
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Howell, Stephen E. L., Mike Brady, and Alexander S. Komarov. "Generating large-scale sea ice motion from Sentinel-1 and the RADARSAT Constellation Mission using the Environment and Climate Change Canada automated sea ice tracking system." Cryosphere 16, no. 3 (March 31, 2022): 1125–39. http://dx.doi.org/10.5194/tc-16-1125-2022.
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Abstract. As Arctic sea ice extent continues to decline, remote sensing observations are becoming even more vital for the monitoring and understanding of sea ice. Recently, the sea ice community has entered a new era of synthetic aperture radar (SAR) satellites operating at C-band with the launch of Sentinel-1A in 2014 and Sentinel-1B (S1) in 2016 and the RADARSAT Constellation Mission (RCM) in 2019. These missions represent five spaceborne SAR sensors that together routinely cover the pan-Arctic sea ice domain. Here, we describe, apply, and validate the Environment and Climate Change Canada automated sea ice tracking system (ECCC-ASITS) that routinely generates large-scale sea ice motion (SIM) over the pan-Arctic domain using SAR images from S1 and RCM. We applied the ECCC-ASITS to the incoming image streams of S1 and RCM from March 2020 to October 2021 using a total of 135 471 SAR images and generated new SIM datasets (7 d 25 km and 3 d 6.25 km) by combining the image stream outputs of S1 and RCM (S1 + RCM). Results indicate that S1 + RCM SIM provides more coverage in the Hudson Bay, Davis Strait, Beaufort Sea, Bering Sea, and directly over the North Pole compared to SIM from S1 alone. Based on the resolvable S1 + RCM SIM grid cells, the 7 d 25 km spatiotemporal scale is able to provide the most complete picture of SIM across the pan-Arctic from SAR imagery alone, but considerable spatiotemporal coverage is also available from 3 d 6.25 SIM products. S1 + RCM SIM is resolved within the narrow channels and inlets of the Canadian Arctic Archipelago, filling a major gap from coarser-resolution sensors. Validating the ECCC-ASITS using S1 and RCM imagery against buoys indicates a root-mean-square error (RMSE) of 2.78 km for dry ice conditions and 3.43 km for melt season conditions. Higher speeds are more apparent with S1 + RCM SIM as comparison with the National Snow and Ice Data Center (NSIDC) SIM product and the Ocean and Sea Ice Satellite Application Facility (OSI SAF) SIM product indicated an RMSE of u=4.6 km d−1 and v=4.7 km d−1 for the NSIDC and u=3.9 km d−1 and v=3.9 km d−1 for OSI SAF. Overall, our results demonstrate the robustness of the ECCC-ASITS for routinely generating large-scale SIM entirely from SAR imagery across the pan-Arctic domain.
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Percival, Glynn. "Induction of Systemic Acquired Disease Resistance in Plants: Potential Implications for Disease Management in Urban Forestry." Arboriculture & Urban Forestry 27, no. 4 (July 1, 2001): 181–92. http://dx.doi.org/10.48044/jauf.2001.020.
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Systemic acquired resistance (SAR) is the phenomenon whereby a plant's own defense mechanisms are induced by prior treatment with either a biological or chemical agent. The concept of SAR has been widely recognized and studied for the past 100 years in relation to increasing resistance to fungal, bacterial, and viral pathogens of economically important crop plants. The use of SAR as part of a disease management strategy in relation to urban forestry has received little scientific investigation despite offering some potential for tree pathogen control. The objectives of this paper are to discuss the concepts of SAR and, where applicable, indicate how SAR may be incorporated into a disease management system by urban foresters. Areas discussed include historical background, persistence of SAR, mechanisms of SAR, induction of SAR by biological organisms and chemicals, interplanting with flowering woody plants to promote an SAR response, and SAR in woody plants.
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Ozawa, Taku, Yuji Himematsu, Akira Nohmi, and Masanori Miyawaki. "Development of Portable SAR for Detection of Volcano Deformation: Application of SAR Interferometry to the Repeated Observation Data." Journal of Disaster Research 17, no. 5 (August 1, 2022): 609–19. http://dx.doi.org/10.20965/jdr.2022.p0609.
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Synthetic aperture radar (SAR), which transmits radar waves from the ground, can detect crustal deformation with high spatial and temporal resolution. To obtain crustal deformation data useful for evaluating volcanic activity, we are developing a portable SAR that can conduct repeated observations without being fixed to the site under Project B of the Integrated Program for Next Generation Volcano Research and Human Resource Development. We named this SAR sensor: SAR for crustal deformation with portable equipment (SCOPE). SCOPE detects crustal deformation over a wide area by repeating observations at several points, which differs from the general ground-based SAR (GB-SAR). SCOPE has four observation types: GB-SAR, car-borne SAR, cart-borne SAR, and man-borne SAR, which are used to conduct such mobile observations efficiently. This study performed repeated observations with a 1-day interval using GB-SAR and car-borne SAR and obtained high coherence and reasonable phase distribution. When using the man-borne SAR type, moderate coherence was obtained. However, focusing on the SAR image was insufficient, and an inappropriate phase slope appeared in the interferogram, suggesting that improvements in the observation and analysis methods remained. We also investigated the temporal persistence of coherence when applying SAR interferometry to the SCOPE data. Sufficient coherence was obtained to detect crustal deformation in sparsely vegetated areas for a data pair at a 1-year interval. Even in densely vegetated areas, sufficient coherence was obtained from the data pair at intervals of several months. These results show that SCOPE has high potential for detecting crustal deformation based on repeated observations.
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Scivier, M. S., M. A. Fiddy, and R. E. Burge. "Estimating SAR phase from complex SAR imagery." Journal of Physics D: Applied Physics 19, no. 3 (March 14, 1986): 357–62. http://dx.doi.org/10.1088/0022-3727/19/3/007.
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Lin, Yueguan, Yida Fan, Chenglong Jiang, Zhiqiang Wang, and Weizeng Shao. "MIMO SAR Using Orthogonal Coding: Design, Performance Analysis, and Verifications." International Journal of Antennas and Propagation 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/629506.
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Multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) is a promising technology in radar imaging which provides a better balance of azimuth resolution and swath width compared with traditional single-input single-output (SISO) SAR. It has the potential to help scientists and engineers to design ambitious SAR system with higher resolution and wider swath. This paper studies the principle of MIMO SAR using orthogonal coding waveform and then provides the performance analysis in resolution and swath width. By using orthogonal coding waveform, lower channel interference is obtained, which makes MIMO SAR achieve wider unambiguous range swath and lower azimuth ambiguity. Simulations are carried out by means of the system parameters of real spaceborne SAR platform. A ground-based MIMO SAR imaging system with up and down chirp modulation is also designed. The performances of MIMO SAR and SISO SAR are compared, and the validity and advantage of MIMO SAR are verified.
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Sun, Yuchuang, Kaijia Yan, and Wangzhe Li. "CycleGAN-Based SAR-Optical Image Fusion for Target Recognition." Remote Sensing 15, no. 23 (November 30, 2023): 5569. http://dx.doi.org/10.3390/rs15235569.
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The efficiency and accuracy of target recognition in synthetic aperture radar (SAR) imagery have seen significant progress lately, stemming from the encouraging advancements of automatic target recognition (ATR) technology based on deep learning. However, the development of a deep learning-based SAR ATR algorithm still faces two critical challenges: the difficulty of feature extraction caused by the unique nature of SAR imagery and the scarcity of datasets caused by the high acquisition cost. Due to its desirable image nature and extremely low acquisition cost, the simulated optical target imagery obtained through computer simulation is considered a valuable complement to SAR imagery. In this study, a CycleGAN-based SAR and simulated optical image fusion network (SOIF-CycleGAN) is designed and demonstrated to mitigate the adverse effects of both challenges simultaneously through SAR-optical image bidirectional translation. SAR-to-optical (S2O) image translation produces artificial optical images that are high-quality and rich in details, which are used as supplementary information for SAR images to assist ATR. Conversely, optical-to-SAR (O2S) image translation generates pattern-rich artificial SAR images and provides additional training data for SAR ATR algorithms. Meanwhile, a new dataset of SAR-optical image pairs containing eight different types of aircraft has been created for training and testing SOIF-CycleGAN. By combining image-quality assessment (IQA) methods and human vision, the evaluation verified that the proposed network possesses exceptional bidirectional translation capability. Finally, the results of the S2O and O2S image translations are simultaneously integrated into a SAR ATR network, resulting in an overall accuracy improvement of 6.33%. This demonstrates the effectiveness of SAR-optical image fusion in enhancing the performance of SAR ATR.
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Li, De Jun, He Nan Wu, Guan Zhong Li, Guang Yang, Li Cheng, and Xiao Rui Sun. "A New Method of SAR Airdrome Image Edge Detection Based on Image Character." Applied Mechanics and Materials 347-350 (August 2013): 3560–64. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.3560.
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SAR image edge detection is one of the basic contents for SAR image processing and analysis, one of SAR airdrome image edge detection methods was advanced in the paper based on the basic character of SAR airdrome image through imaging theory and target statistical trait, SAR image pretreatment was realized by synchronously using median filter, image division and mathematics morphologic, at last SAR image was edge detected using Canny arithmetic operators.
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Huang, Meiyu, Yao Xu, Lixin Qian, Weili Shi, Yaqin Zhang, Wei Bao, Nan Wang, Xuejiao Liu, and Xueshuang Xiang. "A Bridge Neural Network-Based Optical-SAR Image Joint Intelligent Interpretation Framework." Space: Science & Technology 2021 (October 12, 2021): 1–10. http://dx.doi.org/10.34133/2021/9841456.
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The current interpretation technology of remote sensing images is mainly focused on single-modal data, which cannot fully utilize the complementary and correlated information of multimodal data with heterogeneous characteristics, especially for synthetic aperture radar (SAR) data and optical imagery. To solve this problem, we propose a bridge neural network- (BNN-) based optical-SAR image joint intelligent interpretation framework, optimizing the feature correlation between optical and SAR images through optical-SAR matching tasks. It adopts BNN to effectively improve the capability of common feature extraction of optical and SAR images and thus improving the accuracy and application scenarios of specific intelligent interpretation tasks for optical-SAR/SAR/optical images. Specifically, BNN projects optical and SAR images into a common feature space and mines their correlation through pair matching. Further, to deeply exploit the correlation between optical and SAR images and ensure the great representation learning ability of BNN, we build the QXS-SAROPT dataset containing 20,000 pairs of perfectly aligned optical-SAR image patches with diverse scenes of high resolutions. Experimental results on optical-to-SAR crossmodal object detection demonstrate the effectiveness and superiority of our framework. In particular, based on the QXS-SAROPT dataset, our framework can achieve up to 96% high accuracy on four benchmark SAR ship detection datasets.
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Chan, Yee Kit, Yung Chong Lee, and Voon Chet Koo. "Design and Implementation of Synthetic Aperture Radar (SAR) Field-Programmable Gate Array (FPGA)-Based Processor." Applied Sciences 12, no. 4 (February 10, 2022): 1808. http://dx.doi.org/10.3390/app12041808.
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Synthetic aperture radar (SAR) is a unique imaging radar system that is capable of obtaining high-resolution images by using signal-processing techniques while operating in all weather and in the absence of a light source. The potential of SAR in a wide range of applications has led to new challenges in digital SAR processor design. On-board storage of SAR raw data is often not practical for real-time applications. The design of digital SAR processors is always restricted by the available space of the carrier system, data transfer rate, payload capacity and on-board power supplies. As reported in the literature, although customized hardware solutions could offer the desired performance, they are not feasible for low-volume production. This research aims to design and develop an efficient digital SAR processor by using field-programmable gate array (FPGA) with the consideration of hardware resources, processing speed and precision. In this paper, a hardware implementation of an FPGA-based SAR processor is presented. The implementation and architecture of the proposed SAR processor are highlighted in this paper. A MATLAB-based SAR processing range-Doppler algorithm (RDA) was developed as the benchmark for the development of an SAR processor. The target device, Altera Stratix IV GX FPGA EP4SGX230KF40C2, was selected for the design and implementation of an FPGA-based SAR processor. Comprehensive evaluations of the performance of the proposed SAR processor in terms of precision, timing performance and hardware resource utilizations are also presented. The proposed FPGA-based digital SAR processor achieves optimum performance in processing SAR signals for image formation. Evaluation shows that the designed SAR processor is capable of processing SAR images with ±1% difference error as compared to SAR images processed by MATLAB. The results also show a reduction in hardware usage via the implementation of an FPGA-based FFT/IFFT coprocessor. These promising results prove that the performance of the proposed processor is satisfactory and the achieved processing time, as well as the power consumption of the processor, outperformed existing implementations.
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Ji, Penghui, Shiqi Xing, Dahai Dai, and Bo Pang. "Deceptive Targets Generation Simulation Against Multichannel SAR." Electronics 9, no. 4 (March 31, 2020): 597. http://dx.doi.org/10.3390/electronics9040597.
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Traditional synthetic aperture radar (SAR) deceptive jamming can effectively generate deceptive scenes or false targets in SAR images. However, these false targets or scenes can be easily distinguished or eliminated by the multichannel SAR system. To interfere with the multichannel SAR, we first analyzed the results of SAR deceptive jamming generated by one transponder and two transponders against three-channel SAR- ground moving target indication (GMTI). Then, we propose a new deceptive jamming method against three-channel SAR-GMTI by using three synergetic transponders. By modulating each transponder with a complex coefficient, three synergetic transponders can generate false moving targets with the controllable radial velocity and located azimuth position in three-channel SAR-GMTI. Besides, in this paper, we also introduce an algorithm to deploy three transponders reasonably by utilizing the minimum condition number. In the end, a general architecture of multiple transponders deceiving multichannel SAR is given. The proposed method can not only generate deceptive false targets against multichannel SAR-GMTI, but also guide the production of a deceptive digital elevation model (DEM) against multichannel interferometric SAR (InSAR). Simulations verify the effectiveness of the proposed method.
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Kim, Seok, Chan-Mi Song, Seung-Hun Lee, Sung-Chan Song, and Hyun-Ung Oh. "Design and Performance of X-Band SAR Payload for 80 kg Class Flat-Panel-Type Microsatellite Based on Active Phased Array Antenna." Aerospace 9, no. 4 (April 13, 2022): 213. http://dx.doi.org/10.3390/aerospace9040213.
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The small synthetic aperture radar (SAR) technology experimental project (S-STEP) mission aims to develop an innovative spaceborne SAR microsatellite as a constellation of 32 microsatellites featuring a high-resolution stripmap mode of 1 m. The S-STEP is a spaceborne SAR microsatellite technology demonstration program in which innovative approaches have been proposed and investigated for SAR payload system designs for improving the development speed, affordability, size and weight parameters, and quality of SAR satellite systems. In this study, the major design approach includes a bus–payload integrated flat-panel-type SAR payload based on an active phased-array antenna. This study conducted an SAR image performance analysis considering the mission requirements to validate the feasibility of the innovative SAR payload design of the S-STEP. These performance analysis results are presented to demonstrate the effectiveness of the proposed SAR payload design approach under the new space paradigm.
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Chen, Zhanye, Shiyang Tang, Yi Ren, Ping Guo, Yu Zhou, Yan Huang, Jun Wan, and Linrang Zhang. "Curvilinear Flight Synthetic Aperture Radar (CF-SAR): Principles, Methods, Applications, Challenges, and Trends." Remote Sensing 14, no. 13 (June 22, 2022): 2983. http://dx.doi.org/10.3390/rs14132983.
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The research into curvilinear flight synthetic aperture radar (CF-SAR) is the inevitable result of the comprehensive practicality of SAR. The flight path of the SAR platform in real applications, which is highly nonlinear or curvy due to three-dimensional velocity and acceleration, cannot be described by the traditional uniform linear motion model. New mathematical models, signal characteristics, imaging algorithms, and system design criteria must be proposed and investigated for CF-SAR. This paper provides a comprehensive overview of CF-SAR. Firstly, the basic concept, unified model, and general signal characteristics of CF-SAR are defined, derived, and analyzed, respectively. Additionally, the advantages and drawbacks of current methodologies are reviewed. Discussions on the CF-SAR’s applications are presented from the perspective of typical platforms, new configurations, and advanced technologies, which are suitable means to fulfill the increasing user requirements. Finally, the challenges faced by CF-SAR are summarized, and some future trends for the study of CF-SAR are explored. Hopefully, this paper will serve as a reference for SAR researchers/engineers and stimulate the future development and actual application of CF-SAR.
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Ao, Dongyang, Corneliu Octavian Dumitru, Gottfried Schwarz, and Mihai Datcu. "Dialectical GAN for SAR Image Translation: From Sentinel-1 to TerraSAR-X." Remote Sensing 10, no. 10 (October 8, 2018): 1597. http://dx.doi.org/10.3390/rs10101597.
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With more and more SAR applications, the demand for enhanced high-quality SAR images has increased considerably. However, high-quality SAR images entail high costs, due to the limitations of current SAR devices and their image processing resources. To improve the quality of SAR images and to reduce the costs of their generation, we propose a Dialectical Generative Adversarial Network (Dialectical GAN) to generate high-quality SAR images. This method is based on the analysis of hierarchical SAR information and the “dialectical” structure of GAN frameworks. As a demonstration, a typical example will be shown, where a low-resolution SAR image (e.g., a Sentinel-1 image) with large ground coverage is translated into a high-resolution SAR image (e.g., a TerraSAR-X image). A new algorithm is proposed based on a network framework by combining conditional WGAN-GP (Wasserstein Generative Adversarial Network—Gradient Penalty) loss functions and Spatial Gram matrices under the rule of dialectics. Experimental results show that the SAR image translation works very well when we compare the results of our proposed method with the selected traditional methods.
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Liang, Wei, Tengfei Zhang, Wenhui Diao, Xian Sun, Liangjin Zhao, Kun Fu, and Yirong Wu. "SAR Target Classification Based on Sample Spectral Regularization." Remote Sensing 12, no. 21 (November 4, 2020): 3628. http://dx.doi.org/10.3390/rs12213628.
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Synthetic Aperture Radar (SAR) target classification is an important branch of SAR image interpretation. The deep learning based SAR target classification algorithms have made remarkable achievements. But the acquisition and annotation of SAR target images are time-consuming and laborious, and it is difficult to obtain sufficient training data in many cases. The insufficient training data can make deep learning based models suffering from over-fitting, which will severely limit their wide application in SAR target classification. Motivated by the above problem, this paper employs transfer-learning to transfer the prior knowledge learned from a simulated SAR dataset to a real SAR dataset. To overcome the sample restriction problem caused by the poor feature discriminability for real SAR data. A simple and effective sample spectral regularization method is proposed, which can regularize the singular values of each SAR image feature to improve the feature discriminability. Based on the proposed regularization method, we design a transfer-learning pipeline to leverage the simulated SAR data as well as acquire better feature discriminability. The experimental results indicate that the proposed method is feasible for the sample restriction problem in SAR target classification. Furthermore, the proposed method can improve the classification accuracy when relatively sufficient training data is available, and it can be plugged into any convolutional neural network (CNN) based SAR classification models.
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Hu, Liping, Canming Yao, Jian Huang, Jinfan Liu, and Guanyong Wang. "Highly Robust Synthetic Aperture Radar Target Recognition Method Based on Simulation Data Training." International Journal of Antennas and Propagation 2022 (September 21, 2022): 1–15. http://dx.doi.org/10.1155/2022/7537732.
Full textAbstract:
Sufficient synthetic aperture radar (SAR) data is the key element in achieving excellent target recognition performance for most deep learning algorithms. It is unrealistic to obtain sufficient SAR data from the actual measurements, so SAR simulation based on electromagnetic scattering modeling has become an effective way to obtain sufficient samples. Simulated and measured SAR images are nonhomologous data. Due to the fact that the target geometric model of SAR simulation is not inevitably consistent with the real object, the SAR sensor model in SAR simulation may be different from the actual sensor, the background environment of the object is also inevitably different from that of SAR simulation, the error of electromagnetic modeling method itself, and so on. There are inevitable differences between the simulated and measured SAR images, which will affect the recognition performance. To address this problem, an SAR simulation method based on a high-frequency asymptotic technique and a discrete ray tracing technique is proposed in this paper to obtain SAR simulation images of ground vehicle targets. Next, various convolutional neural networks (CNNs) and AugMix data augmentation methods are proposed to train only on simulated data, and then target recognition on MSTAR measured data is performed. The experiments show that all the CNNs can achieve incredible recognition performance on the nonhomologous SAR data, and the RegNetX-3.2GF achieves state-of-the-art performance, up to 84.81%.
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Musyarofah, Hidayatul, Hasbi Yasin, and Tarno Tarno. "ROBUST SPATIAL AUTOREGRESSIVE UNTUK PEMODELAN ANGKA HARAPAN HIDUP PROVINSI JAWA TIMUR." Jurnal Gaussian 9, no. 1 (February 28, 2020): 26–40. http://dx.doi.org/10.14710/j.gauss.v9i1.27521.
Full textAbstract:
Spatial regression analysis is regression method used for type of data has a spatial effect. Spatial regression showing the presence of spatial effects on the response variable (Y) is a Spatial Autoregressive (SAR). Outlier often found in research spatial data. The outlier is called the spatial outliers. The analysis can be used to handle outliers in general is Robust Regression. There are several estimator that can be used in which the estimator Robust Regression S, M, MM and LTS. Meanwhile, Robust Regression were used to handle spatial outlier is a combination of SAR and Regression Robust method to form a new method that is Robust Spatial Autoregressive (Robust SAR). Type estimator used in this study is the S-Estimator. This study was conducted to determine the best model on a case study Life Expectancy of East Java Province. The best model is analyzed by comparing the methods of SAR and SAR Robust method. Based on the analysis results obtained MSE and Adjusted R2 values for the SAR method are 1.7521 and 55.54% while for the Robust SAR method are 0.7456 and 62.30%. The Robust SAR model has a lower MSE value and a higher Adjusted R2 when compared to the SAR model. Thus the best model for modeling the life expectancy in East Java is Robust SAR models.Keywords:Spatial Autoregressive (SAR), Robust SAR, Life expectancy
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Singh, Vijayata, Shweta Roy, Mrunmay Kumar Giri, Ratnesh Chaturvedi, Zulkarnain Chowdhury, Jyoti Shah, and Ashis Kumar Nandi. "Arabidopsis thaliana FLOWERING LOCUS D Is Required for Systemic Acquired Resistance." Molecular Plant-Microbe Interactions® 26, no. 9 (September 2013): 1079–88. http://dx.doi.org/10.1094/mpmi-04-13-0096-r.
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Localized infection in plants often induces systemic acquired resistance (SAR), which provides long-term protection against subsequent infections. A signal originating in the SAR-inducing organ is transported to the distal organs, where it stimulates salicylic acid (SA) accumulation and priming, a mechanism that results in more robust activation of defenses in response to subsequent pathogen infection. In recent years, several metabolites that promote long-distance SAR signaling have been identified. However, the mechanism or mechanisms by which plants perceive and respond to the SAR signals are largely obscure. Here, we show that, in Arabidopsis thaliana, the FLOWERING LOCUS D (FLD) is required for responding to the SAR signals leading to the systemic accumulation of SA and enhancement of disease resistance. Although the fld mutant was competent in accumulating the SAR-inducing signal, it was unable to respond to the SAR signal that accumulates in petiole exudates of wild-type leaves inoculated with a SAR-inducing pathogen. Supporting FLD's role in systemic SAR signaling, we observed that dehydroabietinal and azelaic acid, two metabolites that, in wild-type plants, promote SAR-associated systemic accumulation of SA and priming, respectively, were unable to promote SAR in the fld mutant. FLD also participates in flowering, where it functions to repress expression of the flowering repressor FLOWERING LOCUS C (FLC). However, epistasis analysis indicates that FLD's function in SAR is independent of FLC.
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Dong, Lei, Niangang Jiao, Tingtao Zhang, Fangjian Liu, and Hongjian You. "GPU Accelerated Processing Method for Feature Point Extraction and Matching in Satellite SAR Images." Applied Sciences 14, no. 4 (February 14, 2024): 1528. http://dx.doi.org/10.3390/app14041528.
Full textAbstract:
This paper addresses the challenge of extracting feature points and image matching in Synthetic Aperture Radar (SAR) satellite images, particularly focusing on large-scale embedding. The widely used Scale Invariant Transform (SIFT) algorithm, successful in computer vision and optical satellite image matching, faces challenges when applied to satellite SAR images due to the presence of speckle noise, leading to increased matching errors. The SAR–SIFT method is explored and analyzed in-depth, considering the unique characteristics of satellite SAR images. To enhance the efficiency of matching identical feature points in two satellite SAR images, the paper proposes a Graphics Processing Unit (GPU) mapping implementation based on the SAR–SIFT algorithm. The paper introduces a multi-GPU collaborative acceleration strategy for SAR image matching. This strategy addresses the challenge of matching feature points in the region and embedding multiple SAR images in large areas. The goal is to achieve efficient matching processing of multiple SAR images in extensive geographical regions. The proposed multi-GPU collaborative acceleration algorithm is validated through experiments involving feature point extraction and matching using 21 GF-3 SAR images. The results demonstrate the feasibility and efficiency of the algorithm in enhancing the processing speed of matching feature points in large-scale satellite SAR images. Overall, the paper contributes to the advancement of SAR image processing techniques, specifically in feature point extraction and matching in large-scale applications.
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Bichlmeier, Harald. "Sind die Namen der Saar keltisch oder vorkeltisch?" Zeitschrift für celtische Philologie 66, no. 1 (December 1, 2019): 1–14. http://dx.doi.org/10.1515/zcph-2019-0001.
Full textAbstract:
Abstract A special feature in the history of the hydronym Saar is that in the first centuries of its attestation up to the high Middle Ages it shows two parallel, morphologically different forms, Sar- vs. Sar-Vv-, the longer form being attested earlier. For the shorter form Sar- an Old European formation *Sorā- from a root PIE *ser- ‘(to be) liquid’ seems most probable. For the longer form actually three possibilities exist: either (a new proposal) it is a secondary u̯o-derivative of the aforementioned *Sorā-; or one of two different Celtic etymologies hitherto proposed applies: both claiming u̯o-derivatives, either (less probably) from the root PIE *serh- ‘to approach (with unfriendly intentions)’ or (more probably) from the root PIE *sterh<sub>3</sub>- ‘to stretch, spread, broaden’, both in the end resulting in Late Proto-Celtic *sarau̯o-. As the two attestations in a metrical text reflect Latin Sarāv-, at some point in the history of the name there seems to have been some (analogical) restructuring of the suffix vowel.
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Lim, Jung-Hwan, Jae Wook Lee, Taek-Kyung Lee, Sang-Burm Ryu, Hyeon-Cheol Lee, and Sang-Gyu Lee. "Optimal Design of the Reflector Antenna to Improve Performance of C-Band Quad-Pol ScanSAR Systems." Journal of Electromagnetic Engineering and Science 20, no. 2 (April 30, 2020): 155–57. http://dx.doi.org/10.26866/jees.2020.20.2.155.
Full textAbstract:
The performance of synthetic aperture radar (SAR) antenna determines the quality of images obtained from the spaceborne SAR system, and thus, SAR antenna should be designed to satisfy the target performance of SAR system. The performance indicators of a SAR system, such as ambiguity-to-signal ratio and resolution, also depend on the SAR operation mode. Therefore, it is important to consider the operation mode when designing an SAR antenna. In this paper, we analyzed the SAR antenna’s effect on ScanSAR (scanning synthetic aperture radar) which is a representative wide-swath mode and its quadrature-polarimetric (quad-pol) mode. In addition, we confirmed that the optimal reflector antenna for the C-band quad-pol ScanSAR system can be designed by analyzing the relation between the antenna size and the system performance.
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Zhang, Yanyan, Sheng Chang, Robert Wang, Peng Li, Yongwei Zhang, and Yunkai Deng. "A Novel Weighted Amplitude Modulation (WAM) System for Ambiguity Suppression of Spaceborne Hybrid Quad-Pol SAR." Remote Sensing 14, no. 1 (December 30, 2021): 155. http://dx.doi.org/10.3390/rs14010155.
Full textAbstract:
Quadrature-polarimetric synthetic aperture radar (quad-pol SAR) has extensive applications, including climate zones classification, extraction of surface roughness, soil moisture mapping, moving target indication, and rice mapping. Hybrid quad-pol SAR ameliorates the range ambiguity performance of conventional quad-pol SAR. However, the azimuth ambiguity of its cross-polarized (cross-pol) echo signals is serious, limiting the swath width of SAR. Therefore, this paper proposes a spaceborne weighted amplitude modulation (WAM) full-polarimetric (full-pol) SAR system, and it can suppress the azimuth ambiguity of hybrid quad-pol SAR. The performance boost of the azimuth ambiguity by the two imaging modes of the proposed SAR system is detailed and evaluated with the L-band system parameters. Moreover, the chirp scaling algorithm (CSA) is adopted to execute scene simulations for the two imaging modes. The results indicate that the proposed SAR system can effectively suppress the azimuth ambiguity of hybrid quad-pol SAR and verify the theoretical analysis.
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Khalil Ahmed. "GROWTH PERORMANCE OF TAMARIND (Tamarindus indica L.) SEEDLINGS TO DIFFERENT LEVELS OF SALINITY AND SODICITY." Agricultural Sciences Journal 5, no. 2 (August 31, 2023): 8–18. http://dx.doi.org/10.56520/asj.v5i2.176.
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Agroforestry is a viable land-use option of salt affected soils which ensure the remunerative use of this valuable resource. A two years pot study was carried out to evaluate salinity tolerance of tamarind fruit plant against different levels of salinity and sodicity. Treatments included were: T1 = ECe, 1.17 dS m-1 + SAR, 10.87, T2 = ECe, 6 dS m-1 + SAR, 25, T3 = ECe, 6 dS m-1 + SAR, 35, T4 = ECe, 6 dS m-1 + SAR, 45, T5 = ECe, 8 dS m-1 + SAR, 25, T6 = ECe, 8 dS m-1 + SAR, 35, T7 = ECe, 8 dS m-1 + SAR, 45, T8 = ECe, 10 dS m-1 + SAR, 25, T9 = ECe, 10 dS m-1 + SAR, 35, T10 = ECe, 10 dS m-1 + SAR, 45. Results revealed that no plant was survived at higher level of salinity (10 dS m-1) and sodicity (SAR 45) and complete cessation and mortality was observed in this treatment. Data of survived plants at the end of study showed that salinity and sodicity arrested the growth variables of tamarind seedlings and increasing levels of salinity-sodicity led a reduction of 3.52% to 82.47% in plant height, 1.53% to 84.61% in stem girth, 5.63% to 88.26% in number of leaves and 7.44 to 90.77 in number of branches over control (non-stress) treatment. Therefore, it was concluded that tamarind seedling can withstand and survive at salinity and sodicity level of 10 dS m-1 and SAR 35.
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Wakabayashi, Hiroyuki, Kazuyoshi Hirano, Fumihiko Nishio, Masaaki Aota, and Shuhei Takahashi. "A study of sea ice in the Sea of Okhotsk with SAR data." Polar Record 31, no. 178 (July 1995): 305–14. http://dx.doi.org/10.1017/s0032247400013851.
Full textAbstract:
AbstractThe ‘Okhotsk Sea Ice Observation Experiment’ 93' was carried out in February 1993 in the southern part of the Sea of Okhotsk and in Lake Saroma, Japan. The aim of the experiment was to investigate how effectively Synthetic Aperture Radar (SAR) can monitor sea ice in this region. Satellite data from JERS-1/SAR (J-SAR), ERS-1/SAR CESAR), and SPOT-2/HRV, as well as data from airborne sensors and ground-truth data, were utilized. From the overall analysis of those data, several results were obtained. First, the range of backscatter of the ice cover on Lake Saroma was determined, as well as a relation between ice type and backscatter. Second, a method for making SAR mosaic images was developed to monitor sea ice over a wide area. When comparing J-SAR(L-band) data with E-SAR(C-band) data acquired simultaneously over the same area, J-SAR proved to be superior to E-SAR in showing the existence of sea ice. And third, it was confirmed that the backscatter of E-SAR was correlated to the ice thickness, which may be explained by the relation between the backscatter and the ice-surface temperature.
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Dong, Lei, Tingtao Zhang, Fangjian Liu, Rui Liu, and Hongjian You. "GPU Acceleration for SAR Satellite Image Ortho-Rectification." Remote Sensing 16, no. 7 (April 7, 2024): 1301. http://dx.doi.org/10.3390/rs16071301.
Full textAbstract:
Synthetic Aperture Radar (SAR) satellite image ortho-rectification requires pixel-level calculations, which are time-consuming. Moreover, for SAR images with large overlapping areas, the processing time for ortho-rectification increases linearly, significantly reducing the efficiency of SAR satellite image mosaic. This paper thoroughly analyzes two geometric positioning models for SAR images. In order to address the high computation time of pixel-by-pixel ortho-rectification in SAR satellite images, a GPU-accelerated pixel-by-pixel correction method based on a rational polynomial coefficients (RPCs) model is proposed, which improves the efficiency of SAR satellite image ortho-rectification. Furthermore, in order to solve the problem of linearly increasing processing time for the ortho-rectification of multiple SAR images in large overlapping areas, a multi-GPU collaborative acceleration strategy for the ortho-rectification of multiple SAR images in large overlapping areas is proposed, achieving efficient ortho-rectification processing of multiple SAR image data in large overlapping areas. By conducting ortho-rectification experiments on 20 high-resolution SAR images from the Gaofen-3 satellite, the feasibility and efficiency of the multi-GPU collaborative acceleration processing algorithm are verified.