Besides to the effects from tidal, coastline position changed due to abrasion and accretion.Therefore, it is necessary to detect the position of coastline, one of them by utilizing Landsat data by using edge detection and NDWI filter. Edge detection is a mathematical method that aims to identify a point on a digital image based on the brightness level. Edge detection is used because it is very good to present the appearance of a very varied object on the image so it can be distinguished easily. NDWI is able to separate land and water clearly, making it easier for coastline analysis. This study aimed to

Abstract. Sea surface height anomaly is a oceanographic parameter that has spatial and temporal variability. This paper aims to determine the characters of sea surface height anomaly in the south and north seas of Java Island. To find these characters, a descriptive analysis of monthly anomaly data is performed spatially, zonally and temporally. Based on satellite altimetry data from 1993 to 2010, the analysis shows that the average of sea surface height anomaly varies, ranging from -15 cm to 15 cm. Spatially and zonally, there are three patterns that can be concidered as sea surface height 1 INTRODUCTIONIndonesia is a maritime continent, about 70 percent of its territory consists of water and flanked by two great oceans; Indian and Pacific Ocean. The very vast oceanic zone has great potential and influence on various sectors of human life. Those potentials and influences should be studied and identified for public welfare. An understanding of oceanic physical dynamic or circulation through data analysis can be used to improve human welfare (Dwi, 2010). Adequate availability of temporal and spatial data from oceanographic parameters are required in research activities.The presence of satellite altimetry becomes the appropriate solution in meeting both regional and global needs of oceanographic data (Handoko, 2004). The analysed data generated from satellite altimetry shows pictures of the occurring processes of ocean dynamics and the factors or parameters that are dominant in the ocean dynamics (Digby, 1999 et al., 2001). As a result of global warming and polar ice melting, ocean water volume increases so that the sea surface height rises. One of oceanographic parameters associated with physical dynamics that are discussed in this study are sea surface height anomaly. Sea surface height anomaly is the magnitude of the deviation on the average sea surface height condition (Steward, 2008). Sea surface height is the distance between the sea surfaces to the reference ellipsoid. With the availability of satellite altimetry data from remote sensing technology monitoring, analysis of sea surface height anomaly on seas surrounding Java Island can be done. The purpose of this study is to compare the characteristics of sea surface height anomalies spatially (different areas) and temporally (different time). Teh obtained characteristics of sea surface height anomaly can be used to determine the upwelling zone. Upwelling zones is a potential reservoir for fishing operations. METHODThis study used sea surface height anomaly data from combined (merged) monitoring of multiple satellite altimetry: Topex/Poseidon, Jason-1, Envisat, Jason-2 and Cryosat-2. The data has a spatial resolution of 0.33 ° x 0.33 ° and monthly temporal. The data used in the analysis are from 1993 to 2010. The data sources can be found at ftp://aviso.oceanobs. com/pub/seadatanet/. The study area is the south and north sea of Java Island with zonal boundary from longitude: E 105.33 ⁰ to 114.67 ⁰ and meridional boundary of latitude: S 3.42 ⁰ to 12.01 ⁰. F...

Information points coordinate of potential fishing zones (PFZ) is required by user that to be more effective in conducting fishing operation. The results of thermal front detection using single image edge detection (SIED) asshape contour lines. This research aims to determine points coordinate for potential fishing zone based on detection of thermal fronts sea surface temperatures. To determine point coordinate performed segmentation on detection result according to size fishnet grid. Contour line contained in each grid is a polygon shape. Centroid of each polygon is point coordinate of PFZ. The result of sea surface temperature data processing from Terra/Aqua MODIS and Suomi NPP VIIRS satellite sindicates that method of determination the centroid of polygon is very effective in determining the point coordinate of PFZ. Using that method the processing stages of satellite data to be faster, more efficient and practical due to the information of PFZ is already as points coordinate.

The need for information on potential fishing zones based on remote sensing satellite data (ZPPI) in coastal waters is increasing. This study aims to create an information model of such zones in coastal waters (coastal ZPPI). The image data used include GHRSST, SNPP-VIIRS and MODIS-Aqua images acquired from September 1st-30th, 2018 and September 1st-30th, 2019, together with other supporting data. The coastal ZPPI information is based on the results of thermal front SST detection and overlaying this with chlorophyll-a. The method of determining the thermal front sea surface temperature (SST) used Single Image Edge Detection (SIED). The chlorophyll-a range used was in the mesotropic area (0.2-0.5 mg/m3). Coastal ZPPI coordinates were determined using the polygon centre of mass, while the coastal ZPPI information generated was only for coastal areas with a radius of between 4-12 nautical miles and was divided into two criteria, namely High Potential (HP) and Low Potential (LP). The results show that the coastal ZPPI models were suitable to determine fishing locations around Nias Island. The percentage of coastal ZPPI information generated was around 90% information monthly. In September 2018, 27 days of information were produced, consisting of 11 HP sets of coastal ZPPI information and 16 sets of LP information, while in September 2019 it was possible to produce 29 days of such information, comprising 11 sets of HP coastal ZPPI information and 18 LP sets. The use of SST parameters of GHRSST images and the addition of chlorophyll-a parameters to MODIS-Aqua images are very effective and efficient ways of supporting the provision of coastal ZPPI information in the waters of Nias Island and its surroundings.