Sensor array geometry has a direct impact on the direction-of-arrival (DOA) estimation of a seismic signal. In this paper. we design a planar array that aims to optimize the DOA estimation of a narrowband signal in the sense of the minimum mean-squared-periodic-error (MSPE) obtained by the maximum a-posteriori (MAP) estimator of the DOA. We investigate the MSPE of the MAP estimator as... https://www.macorners.shop/product-category/clear-tote-bag/