As the four Pioneer Venus probes fell within the atmosphere toward the surface of Venus, each of them transmitted a radio signal directly to Earth. Because of the relatively broad antenna beam-width of these small probes, some of the transmitted power went down to the surface ov Venus. I report here the discovery that their characteristics can be determined with a surprising degree of certainty. From these characteristics one can determine parameters of the Venusian atmospheric winds and of the surface that promise to be useful. Most of the scattered energy is that which originally radiated from the probes in a near-horizontal direction; the downward-directed radiation is detectable but much weaker. Refraction in the atmosphere of Venus clearly plays a significant role in establishing both the strength of scatter and its Doppler shift. For this first report, I stress the aspects of analysis that bear on the identification of these weak echoes.