Transducer arrays ,what is gained?

[Andrew Meshel]

Hi
I have noticed that some of the cheaper side scans are using an array of 20 deg transducers all mounted in a row to simulate the 1.2 deg long side scan trans ducers. Does any one understad what they are doing. Do the transducers all nedd to be touching or are they spaced out so there cones of coverage all intersect and give the illusion of one long transducer? the other question is are they giving up resoultion by useing the 20 deg vs the 1.2?

[Jason M]

Re: Transducer arrays ,what is gained?

Another question re transducers.
A single transducer gives say 20 degree coverage in all directions. When you parallel several transducers in a row, the beamwidth of the long axis is reduced, but is the beamwidth of the short axis increased? Would four 20 degree transducers give a beam of 80 x 5 degrees or thereabouts, or would it be something like 20 x 5 degrees?
Any help understanding this would be appreciated.

Jason M.