Abstract: A method for estimating an underwater acoustic sound velocity in a network of acoustic nodes arranged along towed acoustic linear antennas and in which a plurality of acoustic signals are transmitted between the nodes. The method includes: obtaining two predetermined distances each separating a couple of nodes placed along a same first acoustic linear antenna (31); for each couple of first and second nodes, obtaining a first propagation duration of an acoustic signal transmitted between said first node and a third node placed along a second acoustic linear antenna and a second propagation duration of an acoustic signal transmitted between said second node and said third node; and estimating said underwater acoustic sound velocity, as a function of said two predetermined distances and said first and second propagation durations obtained for each couple of nodes.

Abstract: A method for obtaining a node-to-surface distance between a reference surface and a first node belonging to a network of a plurality of nodes arranged along towed acoustic linear antennas. A plurality of acoustic sequences are sent between the nodes. Each sequence is used to estimate an inter-node distance as a function of a propagation duration of the sequence between nodes. After emission by the first node of a given signal: the first node measures a first propagation duration of a first reflection by the reference surface of the given signal, and a first value of the node-to-surface distance is obtained as a function of that first propagation duration; and/or a second node measures a second propagation duration of a second reflection by the reference surface of the given signal, and a second value of the node-to-surface distance is obtained as a function of that second propagation duration.

Abstract: The invention relates to a system and a method of digital communication between synchronized submarine devices, system including means of sending a signal in modulated bit form, at least one sender (100) and at least one receiver (200), characterized in that said at least one sender (100) sends a signal enabling both any data to be transmitted to said at least one receiver (200) and a propagation time between said at least one sender (100) and said at least one receiver (200) to be measured.

Abstract: The invention relates to a system and a method of digital communication between synchronized submarine devices, system including means of sending a signal in modulated bit form, at least one sender (100) and at least one receiver (200), characterized in that said at least one sender (100) sends a signal enabling both any data to be transmitted to said at least one receiver (200) and a propagation time between said at least one sender (100) and said at least one receiver (200) to be measured.