&is paper describes the use of spherical wave expansion (SWE) to model the embedded element patterns of the LOFAR low-band array. &e goal is to reduce the amount of data needed to store the embedded element patterns. &e coefficients are calculated using the Moore–Penrose pseudoinverse. &e Fast Fourier Transform (FFT) is used to interpolate the coefficients in the frequency domain. It turned out that the embedded element patterns can be described by only 41.8% of the data needed to describe them directly if sampled at the Nyquist rate. &e presented results show that a frequency resolution of 1MHz is needed for proper interpolation of the spherical wave coefficients over the 80MHz operating frequency band of the LOFAR low-band array. It is also shown that the error due to interpolation using the FFT is less than the error due to linear interpolation or cubic spline interpolation.
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