An exact expression for the discrimination factor (ratio of maximum‐to‐minimum power response) has been found for a vertical, equally spaced, linear steered array in an axially symmetric, peaked noise field. This quantity was evaluated for half‐wavelength element spacing as a function of the number of elements, and for a 20‐element linear array as a function of the interelement spacing. These calculations refine a previous approximate result obtained by Stone [J. Stone, J. Acoust. Soc. Am.34, 328 (1962)].