A method and system for telemetry through a drilling fluid during drilling
is disclosed. A reflector (110) is positioned downstream from the
drilling mud pumps (80) and causes reflected pressure waves having the
same pressure polarity as incident pressure waves traveling upwards. At
least one pressure sensor (92) is positioned below the reflector (110) to
sense pressure in the drilling fluid. The reflector can be a fixed
orifice plate or an adjustable aperture.