Abstract: Antennas and antenna arrays in low band underwater systems introduce significant linear distortions that affect the detection of broadband signals. The article gives an analysis of the distortions using the space-time impulse response method. The signal received at different directions is subjected to two types of filtration, one matched to the transmitted signal and another one matched to the distorted signal. For the purpose of the simulation the Matlab software was used. Detection performance can be greatly enhanced, if receiver design takes account of the distortions.