| dc.description.abstract | Abstract
The Chung-Li VHF Radar located in mid-latitude area was employed to observe 3-m scale sporadic E field aligned irregularities in this research, besides, 3 dimensional spatial structure of field aligned irregularities was reconstructed by using interferometry technique. In generally, field aligned irregularities could be classified into 3 spatial structures which are layer structure, blob structure and loose structure. Discussion and research were made separately according to different structure. For layer structure irregularities, a retrieved technique to reconstruct its spatial structure has been developed and the mechanism is also discussed in this thesis. Theory of Beam broadening effect is implemented here to study the frozen-in effect of blob structure irregularities (Chu et al., 2007); moreover, the true velocity of entire blob structure is calculated according to beam broadening theory. Due to the damage of former Radar system, a renew action of Chung-Li 52MHz Radar system was completed in January, 2008. The former antenna array employed for ionospheric observation has been rearranged to become an isosceles triangle. A new expected echoing region of latest Radar system was analyzed and modeled by using IGRF model according to the characteristic of field aligned irregularities; in the mean time, the accuracy of new expected echoing region was also checked by elementary observation. To understand the distribution and property of ionospheric electron density, data of satellite FORMOSAT-3/COSMIC was analyzed in this research. For getting higher trustworthy profile data, it is necessary to establish a suitable method for data quality control; hence, a conditional selection method was brought up to control the quality of the profile data of ionospheric E region collected by COSMIC, this results were also verified by chapman theory and ionosonde. Another condition for the selection of F region data was defined due to its different characteristic and its results were compared to IRI model. | en_US |