Deteksi Gangguan Perambatan Sinyal Akibat Letusan Gunung Api Semeru Berdasarkan Metode PPR dan SNR (Studi Kasus : Letusan Desember 2020)

Atmajaya, Aditya Eka Putra (2026) Deteksi Gangguan Perambatan Sinyal Akibat Letusan Gunung Api Semeru Berdasarkan Metode PPR dan SNR (Studi Kasus : Letusan Desember 2020). Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Indonesia adalah negara dengan aktivitas vulkanik dengan intensitas tinggi di dunia. Hal ini menjadikan sistem deteksi letusan gunung api harus dilakukan sedini mungkin. Salah satu gunung api aktif di Indonesia adalah Gunung Api Semeru, pada Desember 2020 terjadi erupsi di Gunung Api Semeru yang menghasilkan kolom abu vulkanik setinggi ±400 m. Selama ini pemantauan aktivitas gunung api masih menggunakan metode konvensional seperti pengamatan visual, seismograf, Tiltmeter, citra satelit optik dan radar cuaca. Namun terdapat kelemahan dari metode tersebut seperti sulit membedakan abu vulkanik dengan awan meteorologis. Oleh karena itu teknologi Global Navigation Satelitte System (GNSS) dapat dimanfaatkan karena dapat digunakan secara pasif dan real-time dengan menggunakan parameter Post-Fit Phase Residual (PPR) dan Signal-to-Noise Ratio (SNR). Terdapat 4 stasiun GNSS yang masih aktif digunakan dan mampu merekam pada saat erupsi terjadi yaitu ARGO, CLUM, LEKR, dan SAWR. Data GNSS dari stasiun tersebut diproses menggunakan perangkat lunak GipsyX untuk mengestimasi parameter PPR, hasil menunjukkan residual mengalami fluktuasi sebelum dan sesudah erupsi dengan perubahan terbesar mencapai -3 meter pada stasiun ARGO. Nilai PPR akan bervariasi negatif ataupun positif. Hal ini dapat terjadi dikarenakan terdapat perbedaan dari data obsevasi dengan model matematis. Berbeda dengan parameter SNR, nilai ini diekstraksi dari file pengamatan RINEX. Hasil menunjukkan penurunan nilai SNR secara signifikan dari 47 dB-Hz ke 38 dB-Hz pada stasiun LEKR. Nilai SNR akan menurun jika sinyal dari satelit ke receiver terhalang oleh plume abu vulkanik sehingga sinyal akan diserap atau terhamburkan. sehingga menyebabkan penurunan nilai SNR. Setelah diketahui nilai residual PPR dan nilai SNR, dilakukan analisis korelasi Pearson. Hasil analisis korelasi Pearson menunjukkan bahwa Stasiun LEKR menunjukkan korelasi negatif sedang dengan nilai r=-0,5976. Dari korelasi tersebut menunjukkan bahwa metode PPR dan SNR dapat digunakan sebagai salah satu metode pemantauan aktivitas gunung api. Penelitian ini diharapkan dapat menjadi dasar pengembangan sistem pemantauan vulkanik berbasis teknologi geodetik di Indonesia.
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Indonesia is one of the countries with the highest levels of volcanic activity in the world. This makes it essential to implement a volcanic eruption detection system as early as possible. One of Indonesia’s active volcanoes is Mount Semeru. In December 2020, an eruption occurred at Mount Semeru that produced a volcanic ash column approximately 400 m high. To date, monitoring of volcanic activity has relied on conventional methods such as visual observation, seismographs, tiltmeters, optical satellite imagery, and weather radar. However, these methods have limitations, such as the difficulty in distinguishing volcanic ash from meteorological clouds. Therefore, Global Navigation Satellite System (GNSS) technology can be utilized because it operates passively and in real-time using the Post-Fit Phase Residual (PPR) and Signal-to-Noise Ratio (SNR) parameters. There are four GNSS stations that are still actively in use and capable of recording data during an eruption: ARGO, CLUM, LEKR, and SAWR. GNSS data from these stations were processed using GipsyX software to estimate the PPR parameter; the results showed that the residuals fluctuated before and after the eruption, with the largest change reaching -3 meters at the ARGO station. The PPR value can vary, either positively or negatively. This can occur due to discrepancies between the observational data and the mathematical model. Unlike the SNR parameter, this value is extracted from the RINEX observation file. The results show a significant decrease in the SNR value from 47 dB-Hz to 38 dB-Hz at the LEKR station. The SNR value decreases when the signal from the satellite to the receiver is obstructed by a volcanic ash plume, causing the signal to be absorbed or scattered, which leads to a decrease in the SNR value. After determining the PPR residual values and SNR values, a Pearson correlation analysis was performed. The results of the Pearson correlation analysis indicate that the LEKR station exhibits a moderate negative correlation with a value of r = -0.5976. This correlation suggests that the PPR and SNR methods can be used as tools for monitoring volcanic activity. This research is expected to serve as a foundation for the development of a geodetic-based volcanic monitoring system in Indonesia.

Item Type: Thesis (Other)
Uncontrolled Keywords: GNSS, Post-Fit Phase Residual, Signal-to-Noise Ratio, Letusan Gunung Api Semeru, Korelasi Pearson. 0953822495 GNSS, Post-Fit Phase Residual, Signal-to-Noise Ratio, Mount Semeru Eruption, Pearson Correlation.
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
Divisions: Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Geomatics Engineering > 29202-(S1) Undergraduate Thesis
Depositing User: Aditya Eka Putra Atmajaya
Date Deposited: 22 Jul 2026 09:07
Last Modified: 22 Jul 2026 09:07
URI: http://repository.its.ac.id/id/eprint/136292

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