Status report August 21 3:17 Boston time
Bruce:
After 26 hours of flight time over a three day period with out a much sleep we are now back on solid New England ground.
Brad, John & I had several objectives.
The first was to understand how to read sonar images. We learned a lot. First a sonar images can not be read (understood) like a photographic image. Trying to determine whether that image on the website is a sub, a sub chaser, a fishing boat, or a destroyer by merely “seeing” what it “looks like” is dead wrong.
What is needed is a 3d model of the target area. That 3d model must address at least three things:
First is the topology of the background around the target. This is important because it affects the shape of the shadow (which is this case is white) Art’s group has the data to build just such a background and intends to do it.
Second it is important to make a model of the hypothetical target (the sub in this case) in which the proportions are consistent with the topological features.
Third we need to show (position) the towfish path in that 3d space so that we can see how the sonar shadows would fall. The towfish is the box holding the electronics that generate sound pulses.
There are other dimensions that need to be considered. The evidence is strong that the target or sub is on a very steep slope and in fact has slid or rolled down quite a ways. It is certainly possible that debris has built up on top of the target which in turn will affect its sonar profile. Bottom line, it is important not to jump to conclusions as to the physical characteristics.
Another objective, remembering the contribution of Yutaka and Minoru, was to locate several Japanese ships lost in the area. The search team has covered the areas where the Arare, the two sub chasers and the I-9 sub were believed to be sunk and found targets. However the analysis on these targets has not yet begun. As you can imagine it is rather time consuming
A third objective was to bring back photos along with the 20 hrs of HV video that Pete has taken. That we have done and the material is fascinating. However, it will take a while to catalogue so that it can be located rapidly. Hopefully in the next few days I can post some of the highlights.
As you can imagine what I have stated here is merely the tip of the iceberg of what has developed into a rather fascinating situation in which a number of people have made incredible contributions.
Hopefully in the coming days I can get a chance to articulate the significance of some of these efforts.
Congratulations on finding the boat! When the Aquila was here in Dutch Harbor I noticed the towing gear and wondered what she was doing. It is amazing that three lost American subs have been found this year. Best of luck to you in the search for the Japanese vessels too. I work in marine logistics for a fishing company, and if there is anything I can do by way of looking for parts or supplies, let me know because I will gladly volunteer my time.