研究期間：10108~10207;Since 1979, the International Beacon Project sponsored jointly by the Northern California DX Foundation and the International Amateur Radio Union has independently built 18 stations transmitting HF beacons at the frequencies of 14.1，18.11，21.15，24.93, and 28.2 MHz. The project was proposed to correct the observation results by international amateur radio stations and to evaluate HF radio wave propagation in the ionosphere. The results can be used to study the ionosphere structure too. In 2004 and 2010, National Central University has built up two NOAA (National Oceanic and Atmospheric Administration) MF/HF radars, also referred as Dynasondes, at ChungLi (24.97°N, 121.19°E) and HuaLien (23.89°N, 121.55°E), separately, in Taiwan. The Dynasondes utilize an interferometric array (including four or eight receivers connected to different spaced dipole antennas) to receive ionospherically reflected signals and/or echoes and is a fully digital research ionosonde capable of providing high precision spatial and temporal ionospheric measurements. Further utilizing a pulse set defined by four pulses transmitted at two closely spaced frequencies, the measured parameters are the time-of-flight and sixteen or thirty-two complex-amplitudes from four or eight receivers. We propose to apply radar interferometry to improve measurements of incident/tilt angles, deduction of velocity estimates and wave parameters, and tracking of HF beacon signals. The further ray-tracing experiments can be used for the study of wave propagation in the ionosphere.
