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09:10-10:40 Session 2: Plenary Session
Location: Pontian-Level 7
Ocean remote sensing and early-career capacity building in the Asia-Pacific region

ABSTRACT. Ensuring equal access to capacity building, ocean science data, and novel technologies is a critical element of conserving and monitoring the ocean we need, for the future we want. At the conclusion of UNFCCC COP27 and the forefront of the UN Decade of Ocean Science for Sustainable Development, we champion the strengthening of science, innovation and international partnerships in the observation of Earth’s natural systems.

The Implementation of National Space Policy 2030 Agenda

ABSTRACT. Malaysia has established the National Space Policy 2030 in 2017 to strengthen the implementation of the agenda of developing, expanding, and popularizing all areas of space technology including remote sensing technology to ensure the continuity of prosperity and progress of the country. The policy objectives are; to state the country’s stand and objectives on mastering the space sector; to coordinate the country’s space activities in an organised manner; to recognise the need for access to space capability; and to determine the direction of development of space sector in Malaysia. Space exploration has produced the space technology and applications which cover various aspect of people’s live. Space technology is widely used and utilized by society in all aspects of life including communication networks, broadcasting, internet, mapping, navigation for transportation and weather forecasting. In line with strategic thrusts of the National Space Policy, Malaysia has developed a Malaysia Space Exploration 2030 Blueprint (Malaysia Space-X 2030) to create a comprehensive national space ecosystem. In line with the aspiration for the country to become a scientific nation for socio-economic transformation and inclusive growth, activities in space technology especially in relation with research, development, commercialisation and innovation continues to be carried out and will enable it to contribute to economy and wellbeing of the country towards Sustainable Development Goals (SDGs).

Monitoring of extreme atmospheric events using satellite microwave sensing.
11:00-12:30 Session 3: Plenary Session
Location: Pontian-Level 7
Space information contribution to Marine and oceanographic resources management in Morocco

ABSTRACT. The 3500 km long Moroccan Atlantic coast is among the richest coasts in marine resources. The Moroccan Exclusive Economic Zone is characterized by a great diversity of fish resources, including about 500 species, 60 of which are currently being harvested. Moreover, the coastal area witnesses a great population dynamic and a concentration of economic and industrial activities, which generate a high pressure on an already vulnerable ecosystem. The exploitation, development and integrated management of oceanographic areas, marine and littoral environments and coastal zones rely heavily on a good understanding of the biophysical parameters of these areas as well as on the specific information describing the status of the resources and their evolutions in space and time. Satellite observation offers a wide range of applications related to these fields and constitutes an essential source of knowledge for the monitoring of marine parameters at various spatial scales and temporal frequencies, like sea surface temperature and the indicators derived from waters colorsdata (chlorophyll, algal blooms, primary production, MES, waters transparency...) in addition to marine pollution, namely the hydrocarbons. Satellite images are also used for the valorization of sea resources and monitoring of their evolution in time and space through the follow-up of indicators describing the environment conditions (upwelling index, thermal fronts, chlorophyll concentration...) and the selection and management of aquaculture sites or the integrated management of coastal areas. Identification of potential of the coastal zones As part of the APPUIT project, co-financed by the European Union and in partnership with the National Institute of Fishery Research, the Royal Center of Remote Sensing developed operational systems and tools for the valorization and management of potential aquaculture sites, to support the development of aquaculture in Morocco. Products, designed from satellite images and in-situ measurements are combined to delimit and characterize the optimal zones for aquaculture farming. A database of maps of various scales, indicators and parameters contributing to the success of an aquaculture farm are initialy produced for three coastal sites with different characteristics (the semi-closed lagoon of Nador, M’diq offshore site, and Dakhla semi-open bay). These indicators are combined according to a multicriteria approach, which takes into consideration the species needs and the farming techniques to delimitate the suitable areas for aquaculture in each site. The goal of this system is to help decision makers in: • Assessing the aquaculture potential of the country ; • Locating the coastal sectors suitable to aquaculture ; • Regularly monitoring the different parameters to spot any possible changes and assess the risks likely to hinder aquaculture projects in each identified site.

Cartography and monitoring of coastal ecosystems To assess satellite images potential in the coastal field, the CRTS analyses the elements and components of the coastal zones and produces cartographic information related to land use, intertidal vegetation, coastline, and to follow-up on their temporal dynamics. The aim of this work is to conduct an objective diagnosis of these fragile sites and to identify the changes that affect them, particularly the vulnerable coastal sites (SIBE, wetlands, lagoons, bays…). This information is exclusively extracted from very high-resolution satellite data, are produced in cartographic and statistical forms with variable spatio-temporal scales, depending on the needs, and covered themes: • The integrated management of the coastal zones; • The development of master plans and appropriate coastal development plans • The valorization of coastal areas (fishing and aquaculture, agriculture, tourism, sand exploitation…); • The conservation of fragile ecosystems (SIBE, lagoons, wetlands…); • The prevention of coastal risks: receding coastlines, silting, erosion… Coastal and marine risk management Within the framework of the European Commission program called SCHEMA, a generic approach, based on modeling scenarios, satellite data and in situ data, was developed to assess tsunami risk in 5 different sites along the Mediterranean and Atlantic coasts, including Rabat-Sale. The THR satellite data were extensively used to produce a precise map of the coastline, used for the modeling of the types of buildings located in the flood-risk areas and the evaluation of their vulnerability degree. An Atlas covering all Moroccan coasts is under preparation. It includes the following maps at 1/5,000 scale that may be useful for all national entities in charge of risks management: • Tsunami risk maps that provide information on potential flood-risk zones, submersion depth and waves heights. • Maps of vulnerability classes of buildings in flood-risk areas that describe the level of resistance of each building considering wave height. • Maps of damage levels suffered by each flooded building based on an approach that combines the degree of vulnerability, the type of building and the wave height.

The COSPAR Capacity Building Initiative – history and future

ABSTRACT. COSPAR's capacity building programme started with the millennium with the intention to strengthen scientific research in developing countries through highly practical regional workshops. Forty workshops, more than 1100 participants later and spanning virtually all areas of space science, part of the diversification we are working on includes long-term collaborations with established organisations such as PORSEC. An overview of the history of our workshops as well as the future perspectives of our programme will be discussed in this talk.

13:30-15:30 Session 4: Progress in Active Remote Sensing Observations from Open Oceans to Coastal Zone 1

Session 1

Location: Pontian-Level 7
Diurnal cycle of surfactant-associated bacteria in the sea surface microlayer and its potential effect on surface slick visibility in SAR
PRESENTER: Mikayla Craven

ABSTRACT. The sea surface microlayer (SML) consists of the upper 1 mm of the ocean’s surface and is an important boundary layer between the air and sea. The SML is occupied by a variety of organisms, including genera of bacteria that are capable of producing surface active agents (surfactants). When surfactants accumulate within the SML they produce sea surface slicks and dampen short gravity-capillary waves. Slicks can be visible to the eye and are sometimes even better seen in synthetic aperture radar (SAR) imagery. SAR technology can also help to visualize the surfactant-associated slicks that are formed due to bacteria processing organic material in the subsurface water (SSW). Understanding of the microbial genera that are capable of surfactant production associated with organic materials, such as dispersed oil or other biological materials in the water column, under different environmental conditions may help to implement SAR technology into global marine ecosystem assessment. In this study, we are focused on the effect of UV exposure on the abundance of surfactant-associated bacteria within the SML and SSW. We have implemented the sampling approach described in detail in Parks et al. (IJRS Special Issue 2020). The in situ microlayer samples were collected in July-August 2018 and November 2019 at two sites in the Straits of Florida (Looe Key and Fort Lauderdale) during RADARSAT-2 satellite overpasses. The DNA microbial data were analyzed at the Argonne National Laboratory using the Illumina MiSeq, a next generation sequencer. This data indicates a statistically significant difference between day and night bacterial abundance in the SML. We hypothesize that the UV exposure of the SML during the day results in a lower abundance of the surfactant-associated bacteria that are sensitive to UV radiation. At the same time a few surfactant- or oil-associated bacteria, which are known to be resistant to UV radiation, were found in the SML mainly during the daytime. The diurnal variability of the surfactant-associated bacteria in the SML may affect the presence of sea surface slicks visible in airborne SAR.

Artificial Neural Network for Precise Satellite Altimetry Sea Levels Estimations: Testing using Simulated Data

ABSTRACT. This paper reports the finding of deep learning technique based on artificial neural network to improve the precision of altimetric sea levels over coastal oceans. It is well-known that waveform retracking protocol is necessary to optimise the estimated geophysical parameters. Most of waveform retracking algorithms are specialised for a specific waveform shapes (e.g. multi-peak, ocean-like and quasi-specular). In attempting to produce precise sea levels from multiple retracking algorithms, one should be concerned about the issue of the existence of relative offset among retrackers, which create ‘a jump’ in the sea level profiles, thus resulting in imprecise sea level estimation. In this study, the neural network technique is explored based 10,000 simulated data, which considered various physical shapes of altimetric waveforms. The data are created using Monte Carlo simulation. The experiment consists of two sets of varying parameters (i.e. number of hidden layer, algorithms in hidden and output layers, and training algorithm). The results indicate that neural network Sets 2 and 3 with 10 and 9 hidden layers are the best parameters for offset reduction. This is indicated by the lowest root mean square error (0.7 cm) and standard deviation of difference (0.2 cm).

Dynamic of Sea Level Anomaly in Indonesian Maritime Continent Revealed from Satellite Data

ABSTRACT. It is known that the trend of sea level change is not only influenced by global sea level rise but is also caused by various factors on a local scale. Therefore, a more in-depth study is needed to find out information on changes in sea level that occur on a local scale. this study is focused on understanding sea level variability in the Indonesian Maritime Continent, specifically to (1) investigate seasonal and inter-annual sea level variability; and (2) compare global and local sea level rise information based on the global SLAs from Copernicus Marine Services (CMEMS) and the local SLAs from the ESA Climate Change Initiative (CCI). This study shows that remote sensing satellite data can identify global and local SLA phenomena. The results showed that the highest global sea level rise trend occurred in the Pacific Ocean region, reaching 8.5 mm/yr. Meanwhile, for LSLR provided by CCI, an in-depth study still needs to be done, considering the noise generated from near the coast data.

Seasonal and Interannual Variability of Sea Level Anomaly in the Banda Sea
PRESENTER: Randi Firdaus

ABSTRACT. Sea level variability plays a critical role in understanding how the Banda Sea influenced the Indonesian Throughflow (ITF), which affects the climate and weather variability on the Maritime Continent. This study analyzed the seasonal and interannual variability of the Sea Level Anomaly (SLA) in the Banda Sea. Monthly Global Ocean Gridded 0.25° × 0.25° SLA dataset provided by CMEMS from 1993 to 2021 was analyzed using Empirical Orthogonal Function (EOF) to describe the Spatio-temporal interannual variability. The results showed that the Banda Sea experienced a sea level rise at a rate of 3.8 – 5.2 mm/yr between 1993 and 2021. During the northwest (southeast) monsoon season, the Banda Sea experienced positive (negative) SLA, with two upwelling regions located in the northeastern Banda Sea and near the Lesser Sunda Islands. Interannually, the first EOF modes explained 98.85% of the SLA variance, with positive anomalies in the entire region. The principal Component (PC) of mode-1 clearly demonstrated the strong influence of ENSO with a correlation of -0.86 in a month lag. Mode-2, characterized by dipole of the positive and negative anomalies in the southern and northern Banda Sea, has been influenced by IOD, as indicated by an intermediate negative correlation (-0.47) between PC mode-2 and DMI with a 6-month lag. Mode-3 is considered a local forcing effect.

Lightweight retroreflective structures as SAR satellite targets

ABSTRACT. In coastal fisheries, especially set-net fisheries, it is important to know the location of the fishing nets. When fishing nets are cut and drifted during disasters such as typhoons, it is necessary to confirm the location of the fishing nets over a wide area. In order to use SAR satellites to locate fishing nets, the nets need to reflect the radar waves (microwaves) of the SAR satellites. In this study, we propose a method of attaching a retro-reflective structure to the inside of a buoy to which the fishing net is attached. The retro-reflective structure attached to the buoy must be low cost and lightweight. We have investigated a method to fabricate a resin corner reflector using a 3D printer and to apply conductive paint on the surface of the corner reflector. SAR satellites.

Estimation Of Absolute Geostrophic Current Over the East Coast of Peninsular Malaysia Using Local Mean Dynamic Topography Derived Based on Local Precise Geoid Model

ABSTRACT. An accurate knowledge of the ocean mean dynamic topography (MDT) is vital for the optimal use of altimetric data to derive absolute geostrophic current. In practice, the MDT will be added to the altimeter-derived sea level anomaly (SLA) to produce absolute dynamic topography. The MDT can be modelled using the most straightforward approach by subtracting a geoid model from an altimetric Mean Sea Surface (MSS) model. Undeniable, with the improvement of altimeter processing technique today, an accurate global MSS model with shorter spatial scales (down to 10–20 km) able to produce, including in the coastal area, became one of the main limitations for the altimeter data before. However, the global geoid model commonly derived using space gravity data has scales larger than 200–300 km and does not match the MSS resolution. Therefore, the ultimate goal of this study is to derive a new local MDT model over the east coast of Peninsular Malaysia using new derived marine geoid model with a contribution of new airborne gravity anomalies. Here, the new marine geoid model will be computed using the Least Squares Modification of Stokes’ Formula (LSMSA). In order to find out the optimum MSS model over the study area, three existing global MSS, namely CNES-CLS2015, DTU21 and UTM20, will be analysed by comparing with the local MSS measured at four tide gauge stations. Besides, the local MDT generated from the new local marine geoid, and each global MSS also will be compared with the in-situ MDT at the three tide gauges. Satellite altimetry data from January 1993 to December 2021 will be processed using Radar Altimeter Database System (RADS) to produce gridded SLA over the study area. Then, the gridded data will be added with the optimum local MDT to generate gridded local ADT and used to derive absolute geostrophic current. In order to analyse the performance of the computed MDT, the absolute geostrophic current derived using the MDT and three existing global MDT, namely DTU18, CNES-CLS 18 and Sandwell model, will be compared with the trajectory of Argos-tracked Drifting Buoys

Developing Marine Geoid Model from Along-track Multi-mission Satellite Altimetry Data across Malaysian Seas

ABSTRACT. Due to the high cost and time constraints, airborne and shipborne surveys have been implemented for geoid and gravity surveys in marine areas with limited coverage. Currently, the satellite altimeter has become an essential tool for global geoid and gravity field recovery, with nearly 60% of the Earth's surface in relation to the height of the ocean could be covered. This enables researchers to replace the conventional marine geoid models, and surveys can be conducted faster with a huge coverage area at a reduced cost. This study attempts to develop a marine geoid model from along-track multi-mission satellite altimetry data using the Least Squares Modification of Stokes with Additive Corrections. The gravity anomaly is computed using Gravity Software, and the planar Fast Fourier Transformation method is applied. The evaluation, selection, blunder detection, combination and re-gridding of the altimetry-derived gravity anomalies and Global Geopotential Model data are demonstrated. The cross-validation approach was employed in the cleaning and quality control of the data with the combination of the Kriging interpolation method. The optimal condition modification parameters of the spherical cap, terrestrial gravity data error and correlation length are applied. Then, the additive corrections based on Downward Continuation, Atmospheric Effects and Ellipsoidal Corrections are combined with the estimated geoid to provide a precise marine geoid over the Malaysian seas. The findings are evaluated with the MyGeoid17 model from the Department of Survey and Mapping Malaysia with up to centimetre accuracy. Hence, the marine geoid model can be utilized for the orthometric height determination in marine areas over the Malaysian Seas.

Developing A Near-Seamless Tidal Datum By Integrating Tidal And Satellite Altimetry Data With A Digital Elevation Model For Maritime Boundary Delimitation

ABSTRACT. Conventionally, information from tide gauge stations are used to produce a localised tidal datum. However, its sparse distribution has caused insufficient tidal datum information in some areas. Nowadays, the integration of satellite altimeters and tide gauge stations has contributed to the development of a continuous tidal datum. This study aims to develop a near-seamless tidal datum for Peninsular Malaysia by integrating tidal and satellite altimetry data, and merging the model with Digital Elevation Model (DEM) for maritime boundary delimitation. The methodology involves tidal data acquisitions for 12 tide gauge stations for Peninsular Malaysia from the Departments of Survey and Mapping Malaysia (DSMM), the extraction of altimetry data from Radar Altimeter Database System (RADS) and tidal prediction for 377 coordinates using Tide Model Driver (TMD) software. The tidal, altimetry and TMD datasets were processed using harmonic analysis in MATLAB software for tidal datum derivation. The validation for the integration of tidal, altimetry and TMD datasets using the Inverse Distance Weighting (IDW) interpolation shows an acceptable standard deviation (STD) and Root Mean Square Error (RMSE) of 0.382 m and 0.557 m for LAT w.r.t MSL, and 0.343 m and 0.530m for HAT w.r.t MSL respectively with 12 coastal tide gauges. Next, the accuracy of the DEMs was assessed in terms of RMSE and correlation coefficient (R) by comparing the derived orthometric height (H) for all five DEMs with GNSS levelling data along the coast of Peninsular Malaysia in Global Mapper software. The result has indicated that the DEM with the best accuracy is TanDEM-X, with a correlation coefficient (R) of 0.959 m and RMSE of 2.574 m, respectively. Finally, the near-seamless tidal datum (LAT w.r.t MSL) was integrated with TanDEM-X using ArcGIS software w.r.t World Geodetic System 1984 (WGS84) ellipsoid for the maritime boundary delimitation. In conclusion, the result has shown a significant improvement in terms of the width of the country’s maritime boundary line compared with the current maritime baseline established by the DSMM. In conclusion, the proposed approach has shown a continuous, consistent, and broader establishment of the country’s maritime baseline for the Peninsular Malaysia region.

15:45-17:00 Session 5: Progress in Active Remote Sensing Observations from Open Oceans to Coastal Zone 2
Location: Pontian-Level 7
Sea Level Rise Estimation and Projection from Long-term Multi-Mission Satellite Altimetry and Tidal Data in the Southeast Asian Region

ABSTRACT. The Southeast Asian region represents a complex geographical location in terms of the coastal area. Most countries in Southeast Asia (SEA) are encircled by the ocean, with lowlands populated massively in coastal areas. With the advantage’s integration of long-term measurement satellite altimetry and tide gauge has allowed research related to climate change, such as sea level rise, to be examined more extensively in spatial and temporal. The sea level anomaly from 25 years of multi-mission satellite altimeter and the tidal data from the tide gauge establishment date to 2018 is approximately 28 years. Then, the projection for every 10 years starting from 2030 until 2100 will analyse using machine learning regression. The projections will be evaluated based on the global model of the Intergovernmental Panel on Climate Change (IPCC). The findings presented that the sea level anomaly and tidal anomaly exhibit good agreement with high correlation (>0.89). Our result of sea level rise trends around Southeast Asia with an overall mean of 4.70 ± 0.37 mm yr−1. The projection of sea level at 2100 will expect to rise 34.97 cm. These outcomes proved that the altimetry data from RADS and the redundant tidal data in measuring the Southeast Asia sea would benefit all government levels. Thus, these results are expected to be valuable for multidisciplinary environmental studies in Southeast Asia, such as flooding, global warming, and climate applications.

Using TPXO model for Chart Datum Modeling Case of study: Algerian coast

ABSTRACT. One of the most important hydrographic operations is the chart datum determination and reduction of measured depth to this surface. The development of continuous hydrographic datums has been a topic of interest in the international hydrographic community [5]. In this work, tidal constituents derived fromTPXO9 used to estimate the chart datum. Data from three tide gauge stations in three different zones located on the north of Algeria are processed by harmonic tidal analysis to evaluate this chart datum, which represents a reference for bathymetric surveying in coastal area. The data analysis process show that two approaches give similar results which indicate that the area of study consist of mixed tides with dominant semidiurnal and diurnal tides with maximum amplitudes 4.1 cm and 5.8 cm, respectively.

Evaluation of Retracked Sea Levels from Jason-2 Altimetry in Halmahera Sea, Indonesia

ABSTRACT. This study examined sea levels of Jason-2 from several retrackers (i.e. Ice, Threshold, Improved Threshold, Fuzzy Logic, ALES, Ice3, Oce3, and Red3). Four years and a quarter data, from February 2011 to May 2015, were assessed over complex Halmahera Sea, Indonesia, particularly within 20 km from the land. Over tested region, altimetry range parameter is critical due to the complex local morphology (e.g. bays, straits, and many small islands). The results showed that most of the applied retrackers offer higher (>85%) percentage of reliable sea level data than the standard Maximum Likelihood Estimator-4 (MLE4) retracker (66%). Retracked sea levels were also in reasonably good agreement with in-situ data (mean correlation < 0.75), compared to standard MLE4 (mean correlation of 0.47). The best performance was found at a distance 10 km from land, with the highest correlation of 0.97 (from Ice3) and the smallest RMSE of 13 cm (from Ice). Based on the findings, it could be concluded that retracked sea levels were superior to standard sea levels, and have high potential for use in related coastal studies at Halmahera Sea and elsewhere with similar water condition such as a complicated coastal topography of Indonesia.

Combined Analysis of Water Exchange between Different Parts of The Caspian Sea Based on Satellite Altimetry and Numerical Simulation Data

ABSTRACT. The paper presents the results of estimation of interannual and seasonal variability of water exchange between the Northern, Middle and Southern Caspian Sea (CS) based on the TOPEX/Poseidon and Jason–1/2/3 satellite altimetry data and results of numerical simulation by the INM (Marchuk Institute of Numerical Mathematics) and HR (Hydrometcenter of Russia) hydrodynamic models. The boundaries between the Caspian Sea sub-basins were taken along the 133 (a line between the Northern and Middle CS) and 209 tracks (a line between the Middle and Southern CS) of the TOPEX/Poseidon and Jason–1/2/3 satellites. Temporal variability of surface geostrophic velocities directed perpendicular to the tracks showed that positive values correspond to the southeast direction of the currents, negative values correspond to the northwest direction. It is clearly seen that the main water exchange associated with the Volga River runoff is concentrated along the western CS coast. Average water exchange through the 133 track is 3.02 Sv, and through the 209 track is 0.5 Sv by numerical simulation. According to remote sensing data total water exchange anomalies through the 133 and 209 tracks show seasonal variability with an amplitude up to ±1.8 Sv for track 133 and ±1.1 Sv for track 209.

Features of the pulse reflected by the water surface in remote sensing devices with a wide antenna pattern
PRESENTER: Yuriy Titchenko

ABSTRACT. Analysis of the reflected pulse to retrieve the parameters of the water surface is a traditional technique for satellite altimetry. With the help of satellite altimetry, mankind has been continuously measuring the significant wave heights and water levels throughout the World Ocean for more than 20 years. A traditional satellite altimeter is equipped with a transceiver antenna with a half power beamwidth of 1.5 degrees. Therefore, the trailing edge of the reflected pulse does not contain information about the water surface and is used only to control the orientation of the antenna. In this paper, we consider the possibilities of the technique for analyzing the pulse reflected by the water surface when used in devices for remote sensing with wide transceiver antenna pattern. The use of a wide antenna pattern makes it possible to observe reflections from facets of the water surface oriented at different angles to the vertical. As a result, the trailing edge of the reflected pulse will contain information about the slopes of the water surface. In this case, the leading edge of the reflected pulse will retain information about the wave height and water level. However, it should be remembered that in traditional orbits of satellite altimeters it will not be possible to use a wide radiation pattern of the transceiver antenna due to the requirements for obtaining a given reflection energy. You can use a wide antenna pattern on aircraft radar altimeters or, for example, in underwater sonars oriented vertically to the water surface. Most of the dependences in this work are built for the case of an underwater pulsed sonar located at a depth of 30 m. The paper compares the shape of the reflected pulse according to the model that considers the slopes of the water surface with the traditional Brown model for satellite altimeters. The dependences of the shape of the reflected pulse on the antenna pattern, on the wave height, on the wave slope variance, on the depth of the sonar, and on the wavelength of the emitted wave are presented.

17:05-18:20 Session 6: Coastal and Ocean Hazards 1
Location: Pontian-Level 7
Application Of Illegal Oil Bilge Dumping Monitoring Using Synthetic Aperture Radar Satellite Sentinel 1a Data And Automatic Identification System Broadcast Signals Over Sunda Strait, Banten Province, Indonesia

ABSTRACT. The existence of oil in nature is widely utilized and very useful for human needs, such as : energy. The world demand for oil is high and need to be transported from the oil producer country into oil consumers. Until now, the most common transportation to transport oil is using ships (tanker ship) passing through the ocean. On the other hand, oil is dangerous to the ocean ecosystem if they were not maintained and treated carefully. Oil is one of the pollutants that make devastating impact on ocean ecosystem. One kind activity that related to the oil pollution is called bilge dumping. Bilge dumping is the disposal of waste water from a ship’s lower hull. Bilge water is supposed to be treated before it’s discharged, but sometimes vessel operators will bypass the pollution control equipment and flush oily, untreated bilge into the ocean, and those activity is direct violation of marine pollution law. Application of Synthetic Aperture Radar (SAR) Satellite using Sentinel 1A data is used in this research as an approach to conduct a preliminary investigation to estimate the oil bilge source. Constant False Alarm Rate (CFAR) algorithm is used to detect ships over the surface of the ocean and Machine Learning using Support Vector Machine (SVM) algorithm is used to detect and distinguished the oil bilge that discharge by the vessel, considering the texture and morphology of the oil in SAR images. Automatic Identification System (AIS) data is used in this research to validate the CFAR algorithm in ship detection and identify the identity of the ship. This research resulting in the detection of 178 km long of bilge oil around the southwest of Banten province, Indonesia. The CFAR algorithm and AIS Broadcasts data identifies an Indonesian oil product tanker as a suspect to the oil bilge dumping activity with at least 15 AIS broadcasts signals recorded by satellite. Estimation of the oil bilge source is conducted by matching the ship track and oil bilge trace. Analysis in this research is utilize the Sentinel 1A data scene captured on July 2nd 2019 at 22:33 Universal Time Coordinate (UTC).

Coastline Changes Along Johor Strait by Using Sentinel-1 Synthetic Aperture Radar Imagery

ABSTRACT. This paper presents the assessment of coastline changes along Johor Straits, Malaysia, using Sentinel-1 Synthetic Aperture Radar (SAR) multi-temporal imageries. The coastline along Johor Strait has been strongly affected by severe erosion and accretion due to climate change and anthropogenic activities despite the construction of various coastal defense structures. Thus, understanding the causes and mechanisms of coastal morphology changes is important to offer optimal coastal management and protection solutions. This study applied the Digital Shoreline Analysis System (DSAS) developed by the United States Geological Survey to calculate the rate of coastline changes from multi-temporal images from 2018 to 2022. The coastline is extracted using the K-means clustering. The rate of changes are calculated using the statistical parameters of End Point Rate (EPR) and Linear Regression Rate (LRR) in the DSAS. The results indicate that the EPR value is −3.83 m/year in 2019-2020 highlighting the most significant erosion at the coastline of Johor Strait. It can be concluded that the Johor Strait experienced significant erosion over the past 5 years and is categorized as “medium erosion” based on the National Coastal Erosion Study (NCES) guidelines.

The Spatiotemporal Changes to Coastal Land Reclamation around Southern Bali Island: Urban Heat Island and Prediction of Seawater Exchange
PRESENTER: Adelina Gaol

ABSTRACT. The land use change and seawater exchange detection is a critical instrument for studying urban growth, mainly caused by reclamation in southern part of Bali and Benoa Bay. Our objectives were to produce historical change on land and coastal for the years 1995 and 2022. For the land aspect, two scenes of Landsat-5 TM (pre-reclamation) and Landsat-9 OLI/TIRS (current conditions) were processed and used. The Normalized Difference Vegetation Index (NDVI) model with precise class value ranges found that the areas for (i) water (dense vegetation) decreased from 1.24 to 0.71 (from 89.21 to 57.87); (ii) built-up, barren land, shrub and grassland and sparse vegetation increased due to population growth in the southern part of Bali tourism area, primarily due to the reclamation of Serangan Island. This result, in line with the average (maximum) LST, remarkably increased from 21.16 oC to 28.09 oC (25 oC to 33.06 oC). The highly residential areas and eco-tourism are responsible for UHI's two-fold growth in 2022 compared to 1995. The second case related to the seawater exchange uses the Finite Volume Coastal Ocean Model (FVCOM) numerical modelling method. The land alterations and area's narrowing from reclamation create changes in current-sea patterns and enhanced current velocity. In addition, increased Benoa Bay's land area is associated with decreasing seawater exchange. The Benoa Bay ecosystems and seawater circulation are automatically disrupted and may threaten marine life.

Evaluation of coastal management for sinking coastal area

ABSTRACT. Numerous variables, whether natural processes or human social and economic activity, have an impact on the degradation of coastal environments. Therefore, greater consideration should be given to a coastal management review that takes the sustainability of the coastal ecosystem into account. The method may include change detection methods by using multi-date remote sensing data and a review based on descriptive deductive-based analysis. A sinking coastal area on the North Java coast of Indonesia was used as the study area. The findings indicate the impact of sinking coastal on the coastal dwelling livelihood, and the management should consider the coastal protection, relocation, and local adaptation and mitigation. Indeed, the findings show the need for coastal spatial planning based on ecosystem approach, which should consist of site selection of relocation, residential and industries as well as coastal protection zone, fisheries culture based on ecosystem, and management of the water resources for inhabitants

High wind speed retrieval algorithm using Ku-band radar data onboard GPM satellite

ABSTRACT. The new method for wind speed retrieval from microwave data at low incidence angles is developed using the data of Ku-band radar onboard GPM (Global Precipitation Measurement) satellite. The radar operates in a scanning mode at low incidence angles. Within the geometrical optics approximation normalized radar cross section at nadir can retrieved in a wide swath and can be used to obtain near surface wind speed. The algorithm for gale winds up to 27 m/s retrieval was developed using ASCAT scatterometer data for training and validation of the model.