A study of the influence of echo carrier frequencies and antenna dimensions on the performance of acoustic-radar antennas is reported with features of practical interest. For a steady-state plane-wave propagation, appropriate expressions are given for the acoustic impedance, the homogeneous boundary conditions analogous to the electromagnetic type of problems, and the time-averaged acoustic energy. Diffraction pattern integral equations for echosonde antennas are evaluated in closed forms using the Zernike polynomials and the generalized-hypergeometric functions, and physical interpretations are given where appropriate. Accurate computer simulations can contribute toward: (1) Better understanding of acoustic remote sensing of atomspheric structure/properties and (2) time-saving/avoidance of hidden problems in field work. Antenna-pattern simulations are examined using modifications of antenna design which improve antenna-system performance. By proper choices of echo carrier frequencies and antenna dimensions, quasiuniform phase distributions pertinent to modest phase shifts of experimental measurements (in striking contrasts with rapidly changing phases of previous results), are obtained. Severe side lobes are major detriments in acoustic remote sensing. Results presented include computer simulations of an antenna employed in probing the marine atmosphere remotely from a moving ship during a cruise in the Pacific Ocean/Caribbean Sea, and simulations of an antenna employed over dry-land; ground-level side lobes versus echo carrier frequencies; and 3-dB beamwidth variations with echo carrier frequencies and with antenna dimensions. For 1–5-kHz carrier-frequency range, acceptable antenna dimensions are 1.22, 1.8, and 1.8 m for the illuminating- transmitting-aperture diameters, and height of the absorbing cuffs, respectively. Half-power beamwidths within 7°–13.5° are obtained in the 1–2-kHz frequency range; and selection of antenna flare angles between 15° and 18° tends to give optimum side-lobe attenuations. Comparisons between theory and measurements show overall good agreements. Maximum relative side-lobe rejections of about −56.5 dB (in good accordance with measurements) in the 20° region near the ground, are obtained at 2-kHz carrier frequency.