scholarly journals KAJIAN APLIKASI PANTULAN SINYAL GNSS UNTUK PEMANTAUAN KETINGGIAN PERMUKAAN AIR LAUT

2019 ◽  
Vol 16 (2) ◽  
pp. 138
Author(s):  
Buldan Muslim ◽  
Charisma Juni Kumalasari ◽  
Novie Chiuman ◽  
Muhammad Ichsan Fadhil Arafah

Design and experiment of ocean current power generation system have been carried out using the Bach In Indonesia, the tsunami early warning system only applies the earthquake and hydrosphere relationship model to predict tsunamis. To date, no tsunami detector has used radar or GNSS technology. GNSS technology can be applied as an early warning system for tsunamis, provided that tsunamis are caused by earthquakes greater than 7 magnitudes, occur 70 kilometers below sea level, and are caused by normal faults. This could be an alternative to Bouy GNSS which is expensive to install and maintain, especially for countries with vast oceans such as Indonesia. In this paper, a review of the application of GNSS signal reflection was carried out using one International GNSS Service (IGS) station, JOG2, and one Continuously Operating Reference Station (CORS), CLSA, each located in Java and Sumatra to investigate the availability of sea level monitoring in Indonesia. Determination of sea level is obtained from two methods, the GNSS signal phase data analysis method and the GNSS Signal-to-Noise Ratio (SNR) data analysis method. Both methods use reflected GNSS signals or multipath effects to obtain sea level. The results of the study show that the number of satellites that pass through Indonesia every 15 minutes is enough to get sea-level data  every 15 minutes to one hour. This shows that it is possible to apply the multipath effect to obtain sea level information in Indonesia to detect tides and tsunamis as part of the tsunami early warning system in Indonesia.

2011 ◽  
Vol 11 (3) ◽  
pp. 731-740 ◽  
Author(s):  
T. Schöne ◽  
J. Illigner ◽  
P. Manurung ◽  
C. Subarya ◽  
C. Zech ◽  
...  

Abstract. Coastal tide gauges do not only play a central role in the study of climate-related sea level changes but also in tsunami warning systems. Over the past five years, ten GPS-controlled tide gauge systems have been installed by the German Research Centre for Geosciences (GFZ) in Indonesia to assist the development of the Indonesian Tsunami Early Warning System (InaTEWS). These stations are mainly installed at the Indonesian coastline facing the Indian Ocean. The tide gauge systems deliver information about the instantaneous sea level, vertical control information through GPS, and meteorological observations. A tidal analysis at the station's computer allows the detection of rapid changes in the local sea level ("sea level events"/SLE), thus indicating, for example, the arrival time of tsunamis. The technical implementation, communication issues, the operation and the sea level event detection algorithm, and some results from recent earthquakes and tsunamis are described in this paper.


2010 ◽  
Vol 10 (2) ◽  
pp. 181-189 ◽  
Author(s):  
C. Falck ◽  
M. Ramatschi ◽  
C. Subarya ◽  
M. Bartsch ◽  
A. Merx ◽  
...  

Abstract. GPS (Global Positioning System) technology is widely used for positioning applications. Many of them have high requirements with respect to precision, reliability or fast product delivery, but usually not all at the same time as it is the case for early warning applications. The tasks for the GPS-based components within the GITEWS project (German Indonesian Tsunami Early Warning System, Rudloff et al., 2009) are to support the determination of sea levels (measured onshore and offshore) and to detect co-seismic land mass displacements with the lowest possible latency (design goal: first reliable results after 5 min). The completed system was designed to fulfil these tasks in near real-time, rather than for scientific research requirements. The obtained data products (movements of GPS antennas) are supporting the warning process in different ways. The measurements from GPS instruments on buoys allow the earliest possible detection or confirmation of tsunami waves on the ocean. Onshore GPS measurements are made collocated with tide gauges or seismological stations and give information about co-seismic land mass movements as recorded, e.g., during the great Sumatra-Andaman earthquake of 2004 (Subarya et al., 2006). This information is important to separate tsunami-caused sea height movements from apparent sea height changes at tide gauge locations (sensor station movement) and also as additional information about earthquakes' mechanisms, as this is an essential information to predict a tsunami (Sobolev et al., 2007). This article gives an end-to-end overview of the GITEWS GPS-component system, from the GPS sensors (GPS receiver with GPS antenna and auxiliary systems, either onshore or offshore) to the early warning centre displays. We describe how the GPS sensors have been installed, how they are operated and the methods used to collect, transfer and process the GPS data in near real-time. This includes the sensor system design, the communication system layout with real-time data streaming, the data processing strategy and the final products of the GPS-based early warning system components.


2011 ◽  
Vol 11 (3) ◽  
pp. 741-749 ◽  
Author(s):  
T. Schöne ◽  
W. Pandoe ◽  
I. Mudita ◽  
S. Roemer ◽  
J. Illigner ◽  
...  

Abstract. On Boxing Day 2004, a severe tsunami was generated by a strong earthquake in Northern Sumatra causing a large number of casualties. At this time, neither an offshore buoy network was in place to measure tsunami waves, nor a system to disseminate tsunami warnings to local governmental entities. Since then, buoys have been developed by Indonesia and Germany, complemented by NOAA's Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys, and have been moored offshore Sumatra and Java. The suite of sensors for offshore tsunami detection in Indonesia has been advanced by adding GPS technology for water level measurements. The usage of GPS buoys in tsunami warning systems is a relatively new approach. The concept of the German Indonesian Tsunami Early Warning System (GITEWS) (Rudloff et al., 2009) combines GPS technology and ocean bottom pressure (OBP) measurements. Especially for near-field installations where the seismic noise may deteriorate the OBP data, GPS-derived sea level heights provide additional information. The GPS buoy technology is precise enough to detect medium to large tsunamis of amplitudes larger than 10 cm. The analysis presented here suggests that for about 68% of the time, tsunamis larger than 5 cm may be detectable.


2017 ◽  
Author(s):  
Sapari D. Hadian ◽  
Ute Lies Siti Khadijah ◽  
Encang Saepudin ◽  
Agung Budiono ◽  
Ayu Krishna Yuliawati

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