Hi John,
We are getting there.

Matt

A couple of teasers:

Garmin 2D:




Garmin SS:

Looking good Matt.

You see Garmin has those terrible ghost lines like the o;d LSS-1 had.

Interesting - with the LSS the lines are caused by a harmonic with the downscan beam where it overlaps - this appears to be the same situation. However, just outside this slightly dead area is a band of enhanced ensonification, where the downscan and sidescan beams actually appear to add to each other. It is in this small band that I have found maximum substrate penetration takes place - revealing objects buried below the visible substrate. From an aesthetic point of view it's pants. From a practical point of view it's actually quite useful.

T

?

and your point is ?.......

"Interesting - with the LSS the lines are caused by a harmonic with the downscan beam where it overlaps - this appears to be the same situation. However, just outside this slightly dead area is a band of enhanced ensonification, where the downscan and sidescan beams actually appear to add to each other. It is in this small band that I have found maximum substrate penetration takes place - revealing objects buried below the visible substrate. From an aesthetic point of view it's pants. From a practical point of view it's actually quite useful."

Sounds very exciting and you must be extremely clever, but it means absolutely nothing to me.

Sorry Trevor.

Nothing constructive to offer then ?

T

www.amazon.com/Handbook-Sidescan-Springe...&keywords=sonar+book

You are, after all, the author of a comprehensive book on the subject. I was rather hoping you might have your own thoughts.

This is an equally good paper - somewhat less costly than the book you quote, but still doesnt deal with the problem of out of phase simultaneous sound pulses from coincident sidescan and downscan beams. I havent found anything yet that does.

onlinelibrary.wiley.com/doi/10.1029/RG028i004p00357/pdf

T,

This is why I have written 2 books, fishermen don't care about these type of books quoted here.

Keep up the good work.

Thanks John

Sidescan isn't only for fishermen though - there are a very large number of sidescan users who couldnt give a hoot about fishing - but use it for dredging, survey, archaeology, biology, diving etc. All these folks have very specialized needs which don't necessarily gel with those of the sport fisherman. Just because a sport fisherman doesnt find something relevant or understandable in a discussion about sidescan doesnt imply that all sidescan users should hold the same opinion.

Reefmaster's sidescan interpretation software is up there with the best of them, and is in several respects groundbreaking. It is of immense value to niche sidescan users, and has recently been instrumental in many internationally important archaeological discoveries. An understanding of the geophysics involved is a crucial aspect of the ongoing research.

It's well worth everyone bearing in mind the richly diverse nature of the user base when contributing to broad based discussions.

T