IONOSPHERIC TOMOGRAPHY USING GPS DATA AROUND INDONESIA TO CHARACTERIZE EARTHQUAKE IMPACT ON IONOSPHERE

• Main Author: SUPRIADI (NIM: 22413017), SLAMET
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20533
• Institution: Institut Teknologi Bandung

Indonesia has a very active ionosphere with a different character comparing to other places. The main source of ionospheric disturbances coming from the top, namely solar activity. But interference from the bottom is still possible to trigger disturbances in the ionosphere.Large earthquake is belived to have impact on ionosphere anomaly and has been described by various methods in many research. In this study the ionosphere disturbance is analyzed by of mapping the residual differential TEC (Total Electron Content) and tomography techniques. However, because of high ionospheric activity, the observation data needs to be corrected and cleaned from cycle slip, as well as the satellite and receivers bias. This study explains how to choose the size of the grid, data interval, and a priori models to increase the number of data. In addition alpha parameter should be selected to decrease the dependencies to the model and checkerboard test is used to assist in the validation of tomography results. The results are applied to the preseismic and postseismic analysis of the Bengkulu earthquake of 2007 impact on the ionosphere.