Abstract: An apparatus and method for correcting the ionospheric distortion of an SAR (Synthetic Aperture Radar) interferogram are disclosed herein. The apparatus includes a multiple aperture SAR interferometry (MAI) interferogram generation unit, a transformed MAI interferogram generation unit, an ionospheric distortion interferogram generation unit, and a corrected SAR interferogram acquisition unit. The multiple aperture SAR interferometry (MAI) interferogram generation unit generates a multiple aperture SAR interferometry (MAI) interferogram using an SAR interferogram. The transformed MAI interferogram generation unit generates a transformed MAI interferogram representative of the azimuth direction derivatives of ionospheric distortion phases using the phases of the MAI interferogram. The ionospheric distortion interferogram generation unit generates an ionospheric distortion interferogram using the transformed MAI interferogram.

Abstract: Disclosed herein is an apparatus for evaluating the safety of a building. The apparatus includes first and second measurement instruments which measure earthquake accelerations of the top and bottom stories, a fast Fourier transform unit which performs fast Fourier transform on the earthquake accelerations, an integration unit which double-integrates the measured earthquake accelerations and creates drift data of the top story and the bottom story, a maximum inter-story drift ratio calculation unit which calculates a maximum inter-story drift ratio, a natural frequency change rate calculation unit which determines a natural frequency of the building, and compares the natural frequency with an ambient natural frequency of the building so as to calculate a natural frequency change rate, and a building safety evaluation unit which compares the maximum inter-story drift ratio and the frequency change rate with preset evaluation criteria and outputs a result of evaluation in the safety of the building.