超音波ドプラ流速計における不要反射波除去のための変調信号の検索 : 多元系列よりの導出

抄録

This paper presents a new modulation method for an ultrasonic Doppler flow meter with high range resolution. In this method, transmitted and received waves are modulated and demodulated respectively depending upon the specified new sequences. The cross-correlation values are zero except for peak value. Is sought a pairof new sequences with such cross-correlation property which provides high sensitivity for detection. The advantages of the proposed method are that it employes continuous waves and enables complete elimination of unfavorable reflected waves. Therefore, the present method is superior to a pulsed Doppler method and an M-sequence modulation method owing to higher detection sensitivity.