||The Chung-Li 30MHz radar observed daytime field-aligned irregularity (FAI) echoes on Dec. 28, 2005. In initial phase correcting process, we find the echoing phase from interferometry do not match with the expect echoing phase, which probably results from the tilte of radar beam pattern in the experiment. The analyzed results presume that the initial phase drifts with time. The results show radar system was unstable on the experiment made on Dec. 28, 2005. Because we don’t exactly know the correct beam pattern information, we can only use the condition that radar could observed irregularity when the radar beam was almost perpendicular to the magnetic field line. Using this property, we may find the expect echoing phase, and then correct the system initial phase and find the right position of irregularity.|
The results from interferometry show irregularities occurred in Ionosphere E region and at an altitude of 170 km. By interferometry, we can also find the position and plasma structure of irregularity in the Ionosphere, and with the spectrum analysis using moment method to calculate the total power, mean Doppler velocity, and spectrum width, which help us to realize the properties of daytime irregularity. The observed properties of daytime irregularities at height of 170 km, including the spectrum width, vertical drift velocity and local time of occurrence are the same as those observed at the equatorial region.
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