53 research outputs found
Unsupervised multi-scale change detection from SAR imagery for monitoring natural and anthropogenic disasters
Thesis (Ph.D.) University of Alaska Fairbanks, 2017Radar remote sensing can play a critical role in operational monitoring of natural and anthropogenic disasters. Despite its all-weather capabilities, and its high performance in mapping, and monitoring of change, the application of radar remote sensing in operational monitoring activities has been limited. This has largely been due to: (1) the historically high costs associated with obtaining radar data; (2) slow data processing, and delivery procedures; and (3) the limited temporal sampling that was provided by spaceborne radar-based satellites. Recent advances in the capabilities of spaceborne Synthetic Aperture Radar (SAR) sensors have developed an environment that now allows for SAR to make significant contributions to disaster monitoring. New SAR processing strategies that can take full advantage of these new sensor capabilities are currently being developed. Hence, with this PhD dissertation, I aim to: (i) investigate unsupervised change detection techniques that can reliably extract signatures from time series of SAR images, and provide the necessary flexibility for application to a variety of natural, and anthropogenic hazard situations; (ii) investigate effective methods to reduce the effects of speckle and other noise on change detection performance; (iii) automate change detection algorithms using probabilistic Bayesian inferencing; and (iv) ensure that the developed technology is applicable to current, and future SAR sensors to maximize temporal sampling of a hazardous event. This is achieved by developing new algorithms that rely on image amplitude information only, the sole image parameter that is available for every single SAR acquisition. The motivation and implementation of the change detection concept are described in detail in Chapter 3. In the same chapter, I demonstrated the technique's performance using synthetic data as well as a real-data application to map wildfire progression. I applied Radiometric Terrain Correction (RTC) to the data to increase the sampling frequency, while the developed multiscaledriven approach reliably identified changes embedded in largely stationary background scenes. With this technique, I was able to identify the extent of burn scars with high accuracy. I further applied the application of the change detection technology to oil spill mapping. The analysis highlights that the approach described in Chapter 3 can be applied to this drastically different change detection problem with only little modification. While the core of the change detection technique remained unchanged, I made modifications to the pre-processing step to enable change detection from scenes of continuously varying background. I introduced the Lipschitz regularity (LR) transformation as a technique to normalize the typically dynamic ocean surface, facilitating high performance oil spill detection independent of environmental conditions during image acquisition. For instance, I showed that LR processing reduces the sensitivity of change detection performance to variations in surface winds, which is a known limitation in oil spill detection from SAR. Finally, I applied the change detection technique to aufeis flood mapping along the Sagavanirktok River. Due to the complex nature of aufeis flooded areas, I substituted the resolution-preserving speckle filter used in Chapter 3 with curvelet filters. In addition to validating the performance of the change detection results, I also provide evidence of the wealth of information that can be extracted about aufeis flooding events once a time series of change detection information was extracted from SAR imagery. A summary of the developed change detection techniques is conducted and suggested future work is presented in Chapter 6
Detection and Monitoring of Marine Pollution Using Remote Sensing Technologies
Recently, the marine habitat has been under pollution threat, which impacts many human activities as well as human life. Increasing concerns about pollution levels in the oceans and coastal regions have led to multiple approaches for measuring and mitigating marine pollution, in order to achieve sustainable marine water quality. Satellite remote sensing, covering large and remote areas, is considered useful for detecting and monitoring marine pollution. Recent developments in sensor technologies have transformed remote sensing into an effective means of monitoring marine areas. Different remote sensing platforms and sensors have their own capabilities for mapping and monitoring water pollution of different types, characteristics, and concentrations. This chapter will discuss and elaborate the merits and limitations of these remote sensing techniques for mapping oil pollutants, suspended solid concentrations, algal blooms, and floating plastic waste in marine waters
Ocean Remote Sensing with Synthetic Aperture Radar
The ocean covers approximately 71% of the Earth’s surface, 90% of the biosphere and contains 97% of Earth’s water. The Synthetic Aperture Radar (SAR) can image the ocean surface in all weather conditions and day or night. SAR remote sensing on ocean and coastal monitoring has become a research hotspot in geoscience and remote sensing. This book—Progress in SAR Oceanography—provides an update of the current state of the science on ocean remote sensing with SAR. Overall, the book presents a variety of marine applications, such as, oceanic surface and internal waves, wind, bathymetry, oil spill, coastline and intertidal zone classification, ship and other man-made objects’ detection, as well as remotely sensed data assimilation. The book is aimed at a wide audience, ranging from graduate students, university teachers and working scientists to policy makers and managers. Efforts have been made to highlight general principles as well as the state-of-the-art technologies in the field of SAR Oceanography
Retrieval of Sea Surface Wind from Sentinel-1A/B SAR Data in the Seas around Korea
학위논문 (석사)-- 서울대학교 대학원 : 사범대학 과학교육과, 2018. 2. 박경애.해상풍은 파도, 해류, 해양 순환 및 대기-해양 상호작용 연구에 중요한 요소 중 하나로, 우리에게 복합적인 해양 현상에 대한 전체적인 이해를 제공한다. 기후변화에 대한 관심이 증대되면서 전 세계 바람장 관측의 중요성이 강조되어 왔고, 그에 따라 European Space Agency (ESA)와 National Aeronautics and Space Administration (NASA)에서는 산란계를 이용하여 전 세계 바람장 자료를 산출해왔다. 이러한 산란계 자료는 ±2 m/s의 정확도를 보여주지만, 낮은 공간 해상도로 인해 연안 바람장 자료의 결핍과 작은 규모의 해양 현상 분석이 불가능하다는 단점을 보인다. Synthetic Aperture Radar (SAR)는 능동 마이크로파를 사용하여 대기 및 기상 상태에 의한 영향이 적고, 수십 m의 공간해상도를 가지고 있어 1 km 이하의 고해상도 바람장 자료 산출이 가능하다. 그로 인해 SAR 자료는 연안 바람장 자료 산출 및 작은 규모의 해양 현상 분석이 가능하다는 장점이 있지만 기존의 SAR 자료에 대한 접근성은 낮았다. Sentinel-1A/B 위성은 C-Band(5.405 GHz) SAR를 탑재한 위성으로, 기존의 SAR 탑재 위성과는 다르게 SAR 자료 수집이 용이하며, Terrain Observation with Progressive Scans SAR (TOPSAR) 기술을 사용하여 관측 범위가 넓기 때문에 다양한 분야 연구에 활발히 사용되고 있다. 본 연구에서는 2015년 5월 1일부터 2017년 9월 30일까지 총 395장의 Sentinel-1A/B Interferometric Wide swath 모드 수직 이중 편파 자료(vertical dual polarization)를 수집하여 처리하였다. Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) 자료를 이용하여 육지 차폐(Land masking) 과정을 거친 후, 적응 임계치 방법(adaptive threshold method)을 적용하여 선박을 탐지하여 제거하고, 스페클 잡음(speckle noise)을 제거하기 위해 배경장을 설정하여 앙상블 평균(ensemble average)을 취하는 전처리 과정을 거쳤다. 전처리 과정을 거친 Sentinel-1A/B 자료를 C-Band VV 편파 산란계 자료를 기반으로 개발된 CMOD4, CMOD_IFR2, CMOD5, CMOD5.N, CMOD5.Na 알고리즘에 적용하여 한반도 주변 해역에서의 고해상도 해상풍을 산출하고, 산출한 결과를 기상청 해양 기상 부이의 실측 자료와 비교하였다. 산출한 결과 Root Mean Square Error (RMSE)가 CMOD4는 1.83 m/s, CMOD_IFR2는 1.82 m/s, CMOD5는 1.69 m/s, CMOD5.N은 1.68 m/s, CMOD5.Na는 1.65 m/s로 나타나 CMOD5.Na 알고리즘이 우리나라 연안 해상풍을 가장 잘 모의하는 것으로 나타났다. 해역별로는 황해 해역이 다른 해역에 비해 편향(bias)이 큰 것으로 나타났는데, 이는 낮은 수심 해역에서의 해저 지형이 해수면 거칠기에 영향을 줘 해상풍의 오차 요인으로 작용한 것으로 해석된다. 본 연구를 통해서 Sentinel-1A/B 자료를 이용하여 산출한 우리나라 주변 연안 고해상도 해상풍 자료는 복잡한 연안 해양 현상 기작에 대한 연구에 활발히 사용될 것으로 기대된다.1. 서론 1
2. 연구 자료 5
2.1. SAR 자료 5
2.2. 대기 모델 자료와 육지 고도 자료 7
2.3. 실측 자료 8
3. 연구 방법 11
3.1. 육지 영역 차폐 및 선박 탐지 방법 11
3.2. 해상풍 산출 방법 15
3.3. 10 m 해상풍 환산 21
3.4. 이중 편파 SAR 자료의 Pol-SAR 분해 24
4. 연구 결과 27
4.1. 일치점 데이터베이스 27
4.2. 해상풍 산출 정확도 29
4.3. 해상풍 산출 오차 분석 34
4.3.1. 수심의 영향 34
4.3.2. 선박의 영향 39
4.3.3. 기름의 영향 41
4.3.4. 기타 영향 44
5. 요약 및 결론 47
참고문헌 48
Abstract 56Maste
Selected Papers from the 2018 IEEE International Workshop on Metrology for the Sea
This Special Issue is devoted to recent developments in instrumentation and measurement techniques applied to the marine field. ¶The sea is the medium that has allowed people to travel from one continent to another using vessels, even today despite the use of aircraft. It has also been acting as a great reservoir and source of food for all living beings. However, for many generations, it served as a landfill for depositing conventional and nuclear wastes, especially in its deep seabeds, and we are assisting in a race to exploit minerals and resources, different from foods, encompassed in it. Its health is a great challenge for the survival of all humanity since it is one of the most important environmental components targeted by global warming. ¶ As everyone may know, measuring is a step that generates substantial knowledge about a phenomenon or an asset, which is the basis for proposing correct solutions and making proper decisions. However, measurements in the sea environment pose unique difficulties and opportunities, which is made clear from the research results presented in this Special Issue
OIL SPILL ALONG THE TURKISH STRAITS SEA AREA; ACCIDENTS, ENVIRONMENTAL POLLUTION, SOCIO-ECONOMIC IMPACTS AND PROTECTION
The Turkish Straits Sea Area (TSSA) is a long water passage that is consisted of the Sea of Marmara, an inland sea within Turkey's borders, and two narrow straits connected to neighboring seas. With a strategic location between the Balkans and Anatolia, the Black Sea and the Mediterranean, and dominated by the continental climate, the region hosted many civilizations throughout the centuries. This makes the region among the busiest routes in the world, with sea traffic three times higher than that in the Suez Canal. The
straits are the most difficult waterways to navigate and witnessed many hazardous and
important collisions and accidents throughout history. In addition, this area has vital roles as a biological corridor and barrier among three distinctive marine realms. Therefore, the region is rather sensitive to damages of national and international maritime activities, which may cause severe environmental problems.
This book addresses several key questions on a chapter basis, including historical accidents, background information on main dynamic restrictions, oil pollution, oil spill detection, and clean-up recoveries, its impacts on biological communities, socioeconomic aspects, and subjects with international agreements. This book will help readers, public, local and governmental authorities gain a deeper understanding of the status of the oil spill, mostly due to shipping accidents, and their related impacts along the TSSA, which needs precautionary measures to be protected.CONTENTS
INTRODUCTION
CHAPTER I - HISTORY OF ACCIDENTS AND REGULATIONS
Remarkable Accidents at the Istanbul Strait
Hasan Bora USLUER and Saim OĞUZÜLGEN …………………………………...... 3
History of Regulations before Republican Era along the Turkish Straits Sea Area
Ali Umut ÜNAL …………………………………………………………………….. 16
Transition Regime in the Turkish Straits during the Republican Era
Osman ARSLAN ……….……………………………………………………….……26
26
The Montreux Convention and Effects at Turkish Straits
Oktay ÇETİN ………………………………………………………………….…….. 33
Evaluation of the Montreux Convention in the Light of Recent Problems
Ayşenur TÜTÜNCÜ ………………………………………………………………… 44
A Historical View on Technical Developments on Ships and Effects
of Turkish Straits
Murat YAPICI ………………………………………………………………………. 55
CHAPTER II - GEOGRAPHY, BATHYMETRY AND
HYDRO-METEOROLOGICAL CONDITIONS
Geographic and Bathymetric Restrictions along the Turkish Straits Sea Area
Bedri ALPAR, Hasan Bora USLUER and Şenol AYDIN ……………………..…… 61
Hydrodynamics and Modeling of Turkish Straits
Serdar BEJİ and Tarkan ERDİK ………………………………………………….… 79
Wave Climate in the Turkish Sea of Marmara
Tarkan ERDİK and Serdar BEJİ …………………………………………………..… 91
CHAPTER III - OIL POLLUTION, DETECTION AND RECOVERY
Oil Pollution at Sea and Coast Following Major Accidents
Selma ÜNLÜ ……………………………………………………………………….101
Forensic Fingerprinting in Oil-spill Source Identification at the Turkish Straits
Sea Area
Özlem ATEŞ DURU ……………………………………………………………… 121
xi
Oil Spill Detection Using Remote Sensing Technologies-Synthetic
Aperture Radar (SAR)
İbrahim PAPİLA, Elif SERTEL, Şinasi KAYA and Cem GAZİOĞLU ……..……. 140
The Role of SAR Remote Sensing to Detect Oil Pollution and Emergency Intervention
Saygın ABDIKAN, Çağlar BAYIK and Füsun BALIK ŞANLI ……….….……….. 157
Oil Spill Recovery and Clean-Up Techniques
Emra KIZILAY, Mehtap AKBAŞ and Tahir Yavuz GEZBELİ …………………… 176
Turkish Strait Sea Area, Contingency Planning, Regulations and Case Studies
Emra KIZILAY, Mehtap AKBAŞ and Tahir Yavuz GEZBELİ …………………... 188
Dispersant Response Method to Incidental Oil Pollution
Dilek EDİGER, Leyla TOLUN and Fatma TELLİ KARAKOÇ ………………….... 205
CHAPTER IV - THE EFFECTS / IMPACTS OF OIL SPILL ON
BIOLOGICAL COMMUNITIES – INCLUDING SAMPLING
AND MONITORING
Marine Microorganisms and Oil Spill
Sibel ZEKİ and Pelin S. ÇİFTÇİ TÜRETKEN …………...………………………… 219
Estimated Effects of Oil Spill on the Phytoplankton Following “Volgoneft-248”
Accident (Sea of Marmara)
Seyfettin TAŞ ………………………………..…………………………………….... 229
Interactions between Zooplankton and Oil Spills: Lessons Learned from Global
Accidents and a Proposal for Zooplankton Monitoring
İ. Noyan YILMAZ and Melek İŞİNİBİLİR ……………………………………..….. 238
The Effects of Oil Spill on the Macrophytobenthic Communities
Ergün TAŞKIN and Barış AKÇALI …………………………….…………….……. 244
Potential Impacts of Oil Spills on Macrozoobenthos in the Turkish
Straits System
Güley KURT-ŞAHİN …………………………………………………………….… 253
The Anticipated Effects of Oil Spill on Fish Populations in Case of an Accident
along the Turkish Straits System – A review of Studies after Several Incidents
from the World
M. İdil ÖZ and Nazlı DEMİREL …………………………………………………….261
Estimated Impacts of an Oil Spill on Bird Populations along the Turkish
Straits System
Itri Levent ERKOL …………………………………………………………….…… 272
The Effect of Oil Spills on Cetaceans in the Turkish Straits System (TSS)
Ayaka Amaha ÖZTÜRK ………………………………………………………….. 277
Changes in the Ichthyoplankton and Benthos Assemblages following
Volgoneft-248 Oil Spill: Case Study
Ahsen YÜKSEK and Yaprak GÜRKAN …………………………………….……. 280
Assessing the Initial and Temporal Effects of a Heavy Fuel Oil Spill
on Benthic Fauna
Yaprak GÜRKAN, Ahsen YÜKSEK ………………………………………..…….. 287
CHAPTER V - SOCIO-ECONOMIC ASPECTS
Socio-economic Aspects of Oil Spill
Özlem ATEŞ DURU and Serap İNCAZ ……………………………………….…… 301
Effects of Oil Spill on Human Health
Türkan YURDUN ………………………………………………………………..…. 313
Crisis Management of Oil Spill, A Case Study: BP Gulf Mexico Oil Disaster
Serap İNCAZ and Özlem ATEŞ DURU …………………………….………….……324
CHAPTER VI - CONVENTIONS RELATING TO PREVENTION
OF OIL SPILL
International Convention for the Prevention of Pollution of the Sea by Oil
(OILPOL), 1954 and its Situation Related with Turkey
Emre AKYÜZ, Metin ÇELİK and Ömer SÖNER …………………………...……... 334
International Convention for the Prevention of Pollution from Ships, 1973, as
Modified by the Protocol of 1978 Relating Thereto and by the Protocol of 1997
(MARPOL)
Özcan ARSLAN, Esma UFLAZ and Serap İNCAZ ………………………….……. 342
Applications of MARPOL Related with Oil Spill in Turkey
Emre AKYÜZ, Özcan ASLAN and Serap İNCAZ ………………………………… 356
Ship Born Oil Pollution at the Turkish Straits Sea Area and MARPOL 73/78
Duygu ÜLKER and Sencer BALTAOĞLU………………………….…………….. 363
International Convention Relating to Intervention on the High Seas in Cases
of Oil Pollution Casualties (INTERVENTION 1969) and its Applications
Related with Oil Spill in Turkey
Şebnem ERKEBAY ……………………………….……………………………….. 371
International Convention on Oil Pollution Preparedness, Response and
Co-operation (OPRC) 1990 and its Applications Related with Oil Spill in Turkey
Kadir ÇİÇEK ………………………………………………………………………. 381
Protocol on Preparedness, Response and Co-operation to Pollution
Incidents by Hazardous and Noxious Substances, 2000 (OPRC-HNS Protocol)
and its Effects in Turkey
Aydın ŞIHMANTEPE and Cihat AŞAN ……………….…………………………. 392
The International Convention on Salvage (SALVAGE) 1989 Related with
Oil Spill in Turkey
İrşad BAYIRHAN ……………………………………….………………..……….. 408
CHAPTER VII - CONVENTIONS COVERING LIABILITY AND
COMPENSATION RELATED WITH OIL SPILL
International Convention on Civil Liability for Oil Pollution Damage
(CLC), 1969 and its Applications
Serap İNCAZ and Pınar ÖZDEMİR ……………………………………..………… 416
1992 Protocol to the International Convention on the Establishment of
an International Fund for Compensation for Oil Pollution Damage
(FUND 1992) and its Applications Related with Oil Spill in Turkey
Ali Umut ÜNAL and Hasan Bora USLUER …………………………….………… 424
International Convention on Liability and Compensation for Damage
in Connection with the Carriage of Hazardous and Noxious Substances
by Sea (HNS), 1996 (and its 2010 Protocol) and its Applications Related
with Oil Spill in Turkey
Bilun ELMACIOĞLU ……………………………………………………………… 437
Bunkering Incidents and Safety Practices in Turkey
Fırat BOLAT, Pelin BOLAT and Serap İNCAZ …………………………………... 447
"Nairobi International Convention on the Removal of Wrecks 2007" and
its Effects on Turkey
Şafak Ümit DENİZ and Serap İNCAZ ……………………….……………………. 457
SAR Remote Sensing of Canadian Coastal Waters using Total Variation Optimization Segmentation Approaches
The synthetic aperture radar (SAR) onboard Earth observing satellites has been acknowledged as an integral tool for many applications in monitoring the marine environment. Some of these applications include regional sea-ice monitoring and detection of illegal or accidental oil discharges from ships. Nonetheless, a practicality of the usage of SAR images is greatly hindered by the presence of speckle noises. Such noise must be eliminated or reduced to be utilized in real-world applications to ensure the safety of the marine environment. Thus this thesis presents a novel two-phase total variation optimization segmentation approach to tackle such a challenging task. In the total variation optimization phase, the Rudin-Osher-Fatemi total variation model was modified and implemented iteratively to estimate the piecewise smooth state by minimizing the total variation constraints. In the finite mixture model classification phase, an expectation-maximization method was performed to estimate the final class likelihoods using a Gaussian mixture model. Then a maximum likelihood classification technique was utilized to obtain the final segmented result. For its evaluation, a synthetic image was used to test its effectiveness. Then it was further applied to two distinct real SAR images, X-band COSMO-SkyMed imagery containing verified oil-spills and C-band RADARSAT-2 imagery mainly containing two different sea-ice types to confirm its robustness. Furthermore, other well-established methods were compared with the proposed method to ensure its performance. With the advantage of a short processing time, the visual inspection and quantitative analysis including kappa coefficients and F1 scores of segmentation results confirm the superiority of the proposed method over other existing methods
Model-Based Pseudo-Quad-Pol Reconstruction from Compact Polarimetry and Its Application to Oil-Spill Observation
Compact polarimetry is an effective imaging mode for wide area observation, especially for the open ocean. In this study, we propose a new method for pseudo-quad-polarization reconstruction from compact polarimetry based on the three-component decomposition. By using the decomposed powers, the reconstruction model is established as a power-weighted model. Further, the phase of the copolarized correlation is taken into consideration. The phase of double-bounce scattering is closer to π than to 0, while the phase of surface scattering is closer to 0 than to π. By considering the negative (double-bounce reflection) and positive (surface reflection) copolarized correlation, the reconstruction model for full polarimetry has a good consistency with the real polarimetric SAR data. L-band ALOS/PALSAR-1 fully polarimetric data acquired on August 27, 2006, over an oil-spill area are used for demonstration. Reconstruction performance is evaluated with a set of typical polarimetric oil-spill indicators. Quantitative comparison is given. Results show that the proposed model-based method is of great potential for oil-spill observation
An investigation on the damping ratio of marine oil slicks in synthetic aperture radar imagery
The damping ratio has recently been used to indicate the relative internal oil thickness within oil slicks observed in synthetic aperture radar (SAR) imagery. However, there exists no well-defined and evaluated methodology for calculating the damping ratio. In this study, we review prior work regarding the damping ratio and outline its theoretical and practical aspects. We show that the most often used methodology yields damping ratio values that differ, in some cases significantly, for the same scene. Three alternative methods are tested on multi-frequency data sets of verified oil slicks acquired from DLR's F-SAR instrument, NASA's Unmanned Aerial Vehicle Synthetic Aperture Radar (UAVSAR) and Sentinel-1. All methods yielded similar results regarding relative thickness variations within slick. The proposed damping ratio derivation methods were found to be sensitive to the proportion of oil covered pixels versus open water pixels in the azimuth direction, as well as to the scene size in question. We show that the fully automatable histogram method provides the most consistent results even under challenging conditions. Comparisons between optical imagery and derived damping ratio values using F-SAR data show good agreement between the relatively thicker oil slick areas for the two different types of sensors
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