利用調頻截斷連續波雷達研究電離層散塊E層電子密度不規則體場列特性

In this project, an attempt will be made to use frequency modulation interruptedcontinuous wave (FMICW) ground wave radar operating at HF band, combinedwith an ionosonde and Chung-Li VHF 52 MHz coherent scatter radar, toinvestigate the field-aligned properties of of decameter-scale electron densityirregularities associate with ionospheric sporadic E layer (Es Layer). In analyzingFMICW ground wave radar echoes from ocean waves and ionospheric electrondensity irregularities, cross spectral analysis is used to compute coherence andphase difference of the echoes between a pair of receiving channels to identifyand detect the ionospheric echoes. After comparing the concurrent ionosphericechoes between 52MHz radar, ionosonde and FMICW radar, we then use radarinterferometry technique to calculate the positions of FAIs in the echoing region.Consequently, with the help of International Geomagnetic Reference Model(IGRF) for constructing expected echoing region, geometry and dynamicbehaviors of the FAIs in the echoing regions can be obtained accordingly,including spatial structure of FAIs, Doppler spectral width, moving velocities ofthe FAIs in the echoing regions, field-aligned property of the irregularities,discrepancies of the drifting velocities of the FAIs at different scales. From theseinformation, field-aligned property of the irregularities can be confirmed, and thewave-turbulence property of the electron density irregularities can be discerned.