PENCITRAAN DISTRIBUSI VERTIKAL UAP AIR DI KAWASAN BANDUNG MENGGUNAKAN TEKNIK GPS TOMOGRAFI 1D

Abstract

GPS is not only useful for navigation and positioning purposes. GPS can also be used for meteorological purposes such as monitoring Earth's atmosphere. GPS signals transmitted from satellites to receivers is distorted and delayed due to particles existence in the troposphere. Water vapor has a significant role in hydrological cycle on Earth. Water vapor is very diverse spatially and temporally. Therefore, troposphere refractivity is diverse too. High-accuracy water vapor monitoring has been challenging in Indonesia. That information is certainly useful for numerical weather prediction and global climate studies. GPS data processing can estimate the magnitude of troposphere bias in zenith direction or well known as Zenith Tropospheric Delay (ZTD). Troposphere bias can then be separated into dry components or Zenith Hydrostatic Delay (ZHD) and water vapor or Zenith Wet Delay (ZWD). In order to know the amount of water vapor content in each signal path, ZWD must be converted to Slant Wet Delay (SWD) by multiplying ZWD and mapping function. SWD are then used to reconstruct vertical water vapor distribution in the troposphere by using tomography technique. This research used GPS observation data from CGPS ITB station for one day. The result shows that Multiplicative Algebraic Reconstruction Technique (MART) was successfully applied to solve linear equations in determining wet refractivity. Further research using CGPS station network and numerical method development can provide more optimal and accurate water vapor distribution.