Alan,
What I found so funny when I first started working at the Postal Service was just how far some of these people would go so as not to seem ignorant about anything...
Being new at the job and unfamiliar with the various terms and phrases, I asked a seasoned employee what "TARE" weight meant as I had seen this term on the side of various shipping containers. His reply was "if too much mail was placed within the container beyond this recommended weight number, the container would tare open!"
For those of you who are unfamiliar with this term as I was, TARE weight is the weight of the container void of any contents. Once weighed, one simply subtracts this tare weight from the total weight to derive at the weight of the contents. (A useful tidbit if using a postal scale to measure the amount of water within a given container)
As to the dirrectionality of the broadband underwater communications systems, these are omni-dirrectional and should be able to pick up incomming transmissions from any dirrection as well. Thus far, Dean has talked to and from two seperate stations from over 300 feet but the maximum range one can communicate with this type of system has yet to be established.
As per earlier discussions, background ambient noise will reduce the overall effective range one can both talk and recieve this type of voice transmission. The louder this background noise, the shorter the range. For lake submarine operations with low to medium suface traffic, it is hoped that this simple form of communications will prove adequate for most submarines.
David Bartsch
From: alanjames@xtra.co.nz
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] collision avoidance sonar pics
Date: Tue, 28 Jul 2009 19:47:46 +1200
Hi David,
Is the broadband communications system fearly reliant on being in a set direction ?
ie would it have to be upward pointing to communicate with the boat or set horizontally at a right angle
to communicate with a sub in that direction, or will the trial be testing this.
Where I fish a lot there are schools of fish feeding noisily on the surface throughout summer, with larger fish underneath.
The passive sonar would be great for tracking the action in a submarine.
I beleive you said you worked for the Postal Service; you'll be looking at those Post Office scales in a differant
light from now on.
Regards Alan
----- Original Message -----
Sent: Tuesday, July 28, 2009 6:43 PM
Subject: RE: [PSUBS-MAILIST] collision avoidance sonar pics
Alan,
I too am anxious to find these things out as well as much of this is unknown or just "gestimates".
One thing for which I am sure of is that many things that would normally not be heard will be easily picked up such as boat traffic even your own boats motors. You could even know when motor bearings are showing wear long before you would otherwise be aware of it.
I am holding my breath and patiently awaiting Kyles in-water performance evaluations. From his report, future sonar system might have to be altered depending upon that which he finds.
His set up incorporates a new type of passive hydrophone that no longer requires an air filled resonance chamber in order to operate. Initial testing results show this hydrophone actually works better when compared side by side with earlier HBH-2 units. The greatest advantage would be a much deeper depth of operation with no air bubble to maintain.
Another bit of sonar news would be that Dean is soon to launch his sub with the first deployed broadband voice underwater communications system installed. Once in the water, He will be in a position to communicate with his other complete system deployed on his support craft and should let us know how well this system works in the field. Console #6 will be installed aboard his friend Kyle's submarine that is already in the water.
David Bartsch
From: alanjames@xtra.co.nz
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] collision avoidance sonar pics
Date: Mon, 27 Jul 2009 09:19:07 +1200
That looks good David,
Be interesting to see what kind of range it has & how wide an angle it picks up on.
Alan
----- Original Message -----
Sent: Sunday, July 26, 2009 10:35 PM
Subject: [PSUBS-MAILIST] collision avoidance sonar pics
To All:
Kyle is in the process of installing a collision avoidance sonar system I recently produced for his K-250 submarine. Take a look under special projects and photos under collision avoidance and my name for some neat pictures! The system was built with small submarines in mind where space is premium.
This system should be under testing in about two weeks and promises to become a must have item.
In that it contains but a single amplification channel, it really represents the most basic passive sonar I can conceive.
It is made from an easily acquired Radio Shack project box and other equally available items for you do-it-yourselfers. Schematics and construction assistance will be available as well as complete builds once the system has been placed thru its paces.
I extend a special thanks to Kyle for trying this set up out for us! I eagerly await is operational analysis and critique.
David Bartsch
Windows Live™ Hotmail®: Celebrate the moment with your favorite sports pics. Check it out.
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