This paper develops a compact theory, which is an important extension of a single element theory previously formulated [S. A. Adekola, J. Acoust. Soc. Am. 62, 524–542 (1977)], for a multielement broadside array of echosondes (acoustic echo‐sounding antennas), uniformly spaced, and consisting of elements that are identical in all respects. The formulation enunciated allows for echosonde array design that gives low side‐lobe strengths, which can considerably minimize any ambiguous target detection of the weak echoes backscattered from the lower atmospheric structure, and an invaluable attribute arrived at, is the directivity‐pattern obtained, which can provide an improved target resolution required in acoustic echo sounding. A workable expression developed for the directivity, provides an inclination that is in good agreement with physical intuition, when expressed in a series form. The theory formulated here, permits an accurate echosonde‐array design when use is made of a computer, and some accurate computer‐generated directivity patterns are produced when an optimization procedure is adopted for the determination of interelement separation required for any particular echosonde array. A number of directivity patterns, illustrating numerous design examples, is presented. Results of several computations show, in general, that if a carrier frequency is specified, then the half‐power beamwidth reduces when the number of array elements is increased, whereas, if the size of the array is given, the 3‐dB beamwidth decreases when the carrier frequency is increased. As an example, when we use a carrier frequency fixed at 2250 Hz, the half‐power beamwidths calculated for a six‐ and twenty‐four‐element array are 6.137° and 5.094°, respectively, whereas the 3‐dB beamwidths obtained when the number of array elements is fixed at twelve, are 7.184° and 4.159° at carrier frequencies that assume values of 1750 and 3500 Hz, respectively. The question of how directivity patterns can be realized without high intensity side lobes that may produce an ambiquity of target resolution, and which may obscure the weak backscattered signal when use is made of the entire echosonde system for remote sensing applications, is investigated, and it is shown that, acceptable side‐lobe reductions can be produced, provided the interelement separation is less than a wavelength, and if a second large interference lobe is attenuated from the visible range of a directivity pattern. A comprehensive design table provided describes some optimum interelement separations which are determined for a number of array elements. For example, an optimum spacing of 0.907λa, where λa is the acoustic wavelength, is determined for an eight‐element array. When the optimum spacing just stated is employed, the directivity pattern computed when uniform, Gaussian and Lorentzian‐line shape distributions are assumed at the illuminating antenna aperture, shows that the side‐lobe attenuations realized are as low as −70 dB in each case.