Radiometer imaging system and method thereof

A method of obtaining an image in a radiometer imaging system including an antenna array and a receiver array, wherein the antenna array includes a plurality of sub-array groups respectively having at least two sub-arrays arranged to form a Y-type configuration, each sub-array is formed of a plurality of antenna elements arranged in a sub-Y-type, each antenna element is responsive to a radiant wave corresponding to a radiant energy emitted from an object, the receiver array has the same number of receivers as the antenna elements, each receiver is associated with one of the antenna elements in a one-to-one correspondence to thereby define a channel, and each receiver generates a first signal having a predetermined band extracted from an output of each antenna element and a second signal having a phase difference of 90 degrees from the first signal, the method comprising the steps of:

• (a) calculating a pixel map coordinate by using position information of the antenna elements in the antenna array, to thereby produce 2-D (two-dimensional) pixel data for the object;
• (b) measuring correlations for channel pairs;
• (c) mapping the correlations correspondingly to the pixel map coordinate;
• (d) performing a 1-D FFT (Fast Fourier Transformation) on the first 2-D pixel data by using values extracted along a first direction of the pixel map coordinate, to thereby obtain first 1-D (one-dimensional) profiles;
• (e) performing a 1-D FFT on values on the first 1-D profiles using values on a first main-axis, to thereby obtain a first 1-D main-axis component profiles which are not influenced by an alias effect among the first 1-D profiles;
• (f) correcting the first 1-D profiles by using the first 1-D main-axis component profile, to produce corrected 1-D profiles in which alias components are removed with respect to the first direction of the pixel map coordinate main-axis;
• (g) performing an inverse FFT (IFFT) on the first corrected 1-D profiles, to thereby recover a first 1-D pixel data;
• (h) performing a 1-D FFT on the first recovered 1-D pixel data using the values extracted along a second direction of the pixel map coordinate perpendicular to the first direction, to thereby generate second 1-D profiles;
• (i) performing a 1-D FFT on the second 1-D profiles using values along the second main-axis, to thereby obtain a second 1-D main-axis component profile, which are not influenced by the alias effect among the first corrected pixel signal, wherein the second main-axis is defined as a diagonal axis with respect to the first main-axis;
• (i) correcting the second 1-D main-axis component profile by using the second 1-D profiles main-axis, to thereby produce a second 1-D corrected profile in which alias components are removed in the second direction;
• (k) performing an inverse FFT on the second 1-D corrected profiles, to thereby obtain a second corrected 1-D pixel data in which the alias components are removed in both directions u and v;
• and
• (l) performing a 2-D FFT on the second corrected pixel data, to thereby obtain a 2-D image for the object.