Results of transmission loss computed by the present method for the 100-m deep Pekeris waveguide problem with a line source. (a) Transmission loss at a depth of 46 m with a lossless bottom; (b) transmission loss at a depth of 46 m with a lossy bottom with an attenuation of 0.5 dB/wavelength; (c) transmission loss versus range and depth with a lossless bottom; (d) transmission loss versus range and depth with a lossy bottom with an attenuation of 0.5 dB/wavelength. The water-bottom interface is indicated by a white line in panels (c) and (d).