Abstract: Provided is a technology for increasing accuracy of position estimation by estimating a position of a signal source based on an error due to altitudes of a sensor and a signal source and an error due to a pitch of an aircraft as well as an error due to curvature of the earth. At this time, a position estimation method may include receiving measurement data from a plurality of sensors, estimating first position data of the signal source based on the measurement data, identifying an altitude error of the first position data, and estimating second position data that is data obtained by correcting the first position data based on the altitude error.

Abstract: Provided is a technology for increasing accuracy of position estimation by estimating a position of a signal source based on an error due to altitudes of a sensor and a signal source and an error due to a pitch of an aircraft as well as an error due to curvature of the earth. At this time, a position estimation method may include receiving measurement data from a plurality of sensors, estimating first position data of the signal source based on the measurement data, identifying an altitude error of the first position data, and estimating second position data that is data obtained by correcting the first position data based on the altitude error.

Abstract: Provided are an apparatus and a method for measuring a frequency of a broadband signal by using low-speed ADCs having sub-Nyquist sampling rates. A plurality of channels each including a low-speed ADC having a sub-Nyquist sampling rate (e.g. sampling frequency from several MHz to hundreds of MHz) are provided, and the frequency of an input signal corresponding to a combination of frequencies calculated through the respective channels is estimated. Therefore, as the number of channels increases, the range of measurable frequencies may be extended.

Abstract: Provided are an apparatus and a method for measuring a frequency of a broadband signal by using low-speed ADCs having sub-Nyquist sampling rates. A plurality of channels each including a low-speed ADC having a sub-Nyquist sampling rate (e.g. sampling frequency from several MHz to hundreds of MHz) are provided, and the frequency of an input signal corresponding to a combination of frequencies calculated through the respective channels is estimated. Therefore, as the number of channels increases, the range of measurable frequencies may be extended.

Abstract: A method for calculating a spacing between antenna elements of an interferometer array antenna includes setting an azimuth of an instantaneous field of view and a distance between phase differences, and obtaining the number of phase difference lines and phase difference vectors with respect to the phase differences of the signals output in a phase comparator of a direction finder, performing a modular arithmetic for the phase difference vectors to obtain phase difference matrixes, obtaining a transformation matrix for linearly transforming the phase difference matrixes and performing the linear transformation using the transformation matrix, calculating a distance between the phase differences on a new axis generated by the linear transformation, and calculating an antenna spacing as an array spacing of the array antenna, the antenna spacing meeting that the distance between the phase differences is greater than a desired distance between phase differences.

Abstract: A method for calculating a spacing between antenna elements of an interferometer array antenna includes setting an azimuth of an instantaneous field of view and a distance between phase differences, and obtaining the number of phase difference lines and phase difference vectors with respect to the phase differences of the signals output in a phase comparator of a direction finder, performing a modular arithmetic for the phase difference vectors to obtain phase difference matrixes, obtaining a transformation matrix for linearly transforming the phase difference matrixes and performing the linear transformation using the transformation matrix, calculating a distance between the phase differences on a new axis generated by the linear transformation, and calculating an antenna spacing as an array spacing of the array antenna, the antenna spacing meeting that the distance between the phase differences is greater than a desired distance between phase differences.