Current Markers
115
c
Fig. 4.15. Principle of side-scanning echo sounder. a Water surface; b Sea floor with ripples, rocks ,
and a small depression (Ieji); c a section of the acoustic recording (sonograph). To Outgoing pulse
of the towed submerged sound source (the "fish"); Tl, T2, etc. , time markers (= distance to sound
reflecting object); Sh acoustic shadow; Fl, F2 schools of fish , and their acoustic image; d width of
insonification on the sea floor (= resolving power); hw distance "fish" to water surface (WS):
hb distance "fish" to sea floor. [R. S. Newton et aI. , 1973, Meteor Forschungsergeb. Reihe C 15; 55]
115
c
Fig. 4.15. Principle of side-scanning echo sounder. a Water surface; b Sea floor with ripples, rocks ,
and a small depression (Ieji); c a section of the acoustic recording (sonograph). To Outgoing pulse
of the towed submerged sound source (the "fish"); Tl, T2, etc. , time markers (= distance to sound
reflecting object); Sh acoustic shadow; Fl, F2 schools of fish , and their acoustic image; d width of
insonification on the sea floor (= resolving power); hw distance "fish" to water surface (WS):
hb distance "fish" to sea floor. [R. S. Newton et aI. , 1973, Meteor Forschungsergeb. Reihe C 15; 55]