福爾摩沙衛星與同相散射雷達反演電離層散塊E層結構-觀測與模擬

Theoretical simulation has revealed that the perturbation pattern of the GPS radio occultation (RO) signal received by the GPS receiver on the a low Earth orbit (LEO) satellite, which pierces through a horizontally stratified ionospheric sporadic E (Es) layer, should follow a specific fork-like form, i.e., with very large amplitudes at the edges of the Es layer and very weak signal in the middle of the layer. However, the FORMOSAT-3 GPS RO data show that the fork-like bifurcation pattern in the GPS amplitude perturbations are not common to see. In this project, an attempt is made to compare the Es layers observed by the Chung-Li VHF radar with those measured by the FORMOSAT-3 or FORMOSAT-7 to explore the effect of spatial properties (e.g., tilted angle, thickness, displacement, electron density fluctuations, and so on ) of the Es layer on the fluctuation pattern of the GPS RO signal. In addition to the radar observation, theoretical simulations of the the amplitude perturbations of the GPS RO signal piercing through an Es layer with different spatial properties are also performed.