Abstract: The present invention discloses a method and system for determining a horizontal distance between a transmitting point and a receiving point. The method obtains a depth value of the transmitting point and a depth value of the receiving point. An area of a sound velocity profile according to the depth value of the transmitting point and the depth value of the receiving point is then determined. A sound velocity gradient according to the area of the sound velocity profile is also determined. The horizontal distance between the transmitting point and the receiving point according to the sound velocity gradient is then determined by calculations. The present invention eliminates the need to calculate a grazing angle of an eigen sound ray(wave) connecting the transmitting point and the receiving point, by directly converting a propagation time into the horizontal distance, thereby quickly and efficiently calculating the horizontal distance between the transmitting point and the receiving point.

Abstract: The present invention discloses a method for determining an effective sound velocity in the deep sea. The method is applied to an apparatus for determining an effective sound velocity in the deep sea having a transmission point, a receiving point, and an underwater mobile carrier. The transmission point is installed on the sea surface such that the depth of the transmission point is unchanged. The receiving point is installed on the underwater mobile carrier such that the depth of the receiving point changes with movement of the underwater mobile carrier. The underwater mobile carrier can measure a sound velocity profile between the transmission point and the receiving point and a horizontal distance between the transmission point and the receiving point.

Abstract: The present invention discloses a method and system for determining a horizontal distance between a transmitting point and a receiving point. The method obtains a depth value of the transmitting point and a depth value of the receiving point. An area of a sound velocity profile according to the depth value of the transmitting point and the depth value of the receiving point is then determined. A sound velocity gradient according to the area of the sound velocity profile is also determined. The horizontal distance between the transmitting point and the receiving point according to the sound velocity gradient is then determined by calculations. The present invention eliminates the need to calculate a grazing angle of an eigen sound ray(wave) connecting the transmitting point and the receiving point, by directly converting a propagation time into the horizontal distance, thereby quickly and efficiently calculating the horizontal distance between the transmitting point and the receiving point.

Abstract: The present invention discloses a method for determining an effective sound velocity in the deep sea. The method is applied to an apparatus for determining an effective sound velocity in the deep sea having a transmission point, a receiving point, and an underwater mobile carrier. The transmission point is installed on the sea surface such that the depth of the transmission point is unchanged. The receiving point is installed on the underwater mobile carrier such that the depth of the receiving point changes with movement of the underwater mobile carrier. The underwater mobile carrier can measure a sound velocity profile between the transmission point and the receiving point and a horizontal distance between the transmission point and the receiving point.