Waveform Retracking Satelit Jason 2 Tahun 2012 Di Pesisir Pulau Mentawai, Sumatera Barat

Abstract

Waveform retracking used for the satellite Jason 2 is a retracking method for analyzing waveform pulse shapes that were repeatedly transmitted from sea surface and received by Altimetry Satellite sensor. Waveform shape affected by the noise when it approaches the shore and this forms are difficult to analyze, but such effect is dissapeared when the wave formed on the open seas. The location for this research is the coastal areas Mentawai, West Sumatra with the Jason 2 satellite during 2012 using Sensor Geophysical Data Recordtype D (SGDR-D) data and Earth Gravitational Model 2008 global geoid (EGM08) data. The purpose of this research was to compare the result of the waveform retracking to the ocean retracking method in coastal areas, analyze Improvement Precentage (IMP) values of Sea Surface Height (SSH) changes, and SSH during 2012 period. This research uses tracks with the number 001 on periods of 130, 135, 148, 151, 162, and 164 with distance category 0 – 10 km, 10 – 50 km, and 50 – 100 km. The waveform analysis are Offset Centre of Gravity (OCOG), ocean, ice, threshold (level 10%, 20%, 50%), and improve retracking (level 10%, 20%, 50%). Waveform shape in the Mentawai coast, West Sumatra were peak echoes. Waveform shape that formed on the open seas has the ideal shape, which is brown + peaky echoes. Performance in each waveform retracking methods are different in each distance. Threshold 10% method is the most optimal method for analyzing waveform contained in every track. Sea surface height average from geoid in track 001 during 2012 period in West Monsoon (November-April) is the 5,03 m, whereas East Monsoon (May-October) is the 4,91 m and the most optimal method is the threshold 10%.