Interlaced video display of sea bottom using sonic energy

Claim 1

A RECORDING APPARATUS FOR USE IN OBTAINING AN INTERLACED VIDEO IMAGE FROM SONIC ECHOES RETURNED AT A PARTICULAR PERIODICITY FROM SUCCESSIVE TRANSVERSE PARALLEL THIN APPROXIMATELY RECTANGULAR SEGMENTS OF AN ELONGATED STRIP AREA OF APPROXIMATELY CONSTANT WIDTH AND WHEREIN EACH OF THE ECHOES IS RETURNED WITH RANGE RESOLUTION RELATIVE TO ONE SIDE OF SAID ELONGATED AREA AS A FUNCTION OF TIME COMPRISING FIRST AND SECOND TAPE TRANSPORTS, A TAPE SUPPORT AND GUIDE MEANS FOR EACH OF THE TAPE TRANSPORTS, DEFINING A TAPE PATH HAVING A STRAIGHT PORTION AND A SEMICIRCULAR LOOP PORTION, THE TWO SEMICIRCULAR LOOP PORTIONS OF THE RESPECTIVE TAPE PATHS BEING OF EQUAL LENGTH, MEANS FOR DRIVING SAID TAPE TRANSPORTS AT EQUAL AND CONSTANT SPEED, A RECORDING HEAD FOR EACH TAPE TRANSPORT, MEANS FOR RECIPROCATING EACH RECORDING HEAD ALONGSIDE THE STRAIGHT PORTIONS OF THE RESPECTIVE TAPE PATHS FOR RECORDING ALTERNATELY ALONG THEIR RESPECTIVE TAPE PATHS, TAPE READOUT MEANS FOR EACH OF THE SEMICIRCULAR LOOP PORTIONS OF THE RESPECTIVE TAPE PATHS, MEANS FOR DRIVING THE READOUT MEANS SO THAT THEY TRANSVERSE THEIR RESPECTIVE SEMICIRCULAR PORTIONS OF THE TAPE PATHS ALTERNATELY AND AT A SPEED SUCH THAT BOTH READOUT MEANS COMPLETE ONE TRAVERSE EACH OF THEIR RESPECTIVE SEMICIRCULAR TAPE PATH PORTIONS IN THE SAME LENGTH OF TIME THAT EACH OF SAID RECORDING HEADS COMPLETES A RECORDING TRAVERSE OF THE STRAIGHT PORTION OF THE RESPECTIVE TAPE PATH.