METHOD AND APPARATUS OF SURVEYING NODULAR TARGETS ON THE SEA FLOOR

摘要

ABSTRACT OF THE DISCLOSURE:In a method and apparatus for surveying for nodulartargets of a grain size of 1 to 15 cm present on the seafloor, pulse waves in each of three frequency ranges of 3 to4, 10 to 14 and 25 to 50 KHz are radiated onto the sea floorfrom a ship navigating on the sea. The reflected sound wavesof the three frequency pulse waves are received and thereflexibilities of the respective sound waves are measuredfrom the reflected sound pressures and the reflexibilitiesare composed. The population of the nodular targets isdetermined from the composed reflexibility and, as required,the grain size of the nodular targets can be determined fromat least one of the ratio of the reflexibility of the soundwaves of the frequency range of 3 to 4 KHz to the composedreflexibility and the ratio of the reflexibility of the soundwaves of the frequency range of 3 to 4 KHz to the reflexibilityof the sound waves of range of 25 to 50 KHz.- 1 -