Underwater infrared camera

[VicS]

I don't think infra red would be any good at all under water. If I remember correctly water absorbs infra red so would be opaque to it.

<hr width=100% size=1><font color=purple>Ne te confundant illegitimi.</font color=purple>

 

[T_S]

Re: he meant...

Mind you, with all this wonderful 'state of the art' gadgetry on board I cannot help thinking that Rule 5 of the colregs could be slightly ignored!

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[Ships_Cat]

Sorry I have not been able to come back with a reponse sooner than this but it takes time to do a few tests.

Have had the spectroscopy team here at Ship Hydrodynamic Investigations and Technologies working hard on it for the last 12 hours or so (a bottle of whisky would be appreciated they say). Here is what they found.

Using our Fourier Transform Spectrascope they determined that the absorption of infra-red by seawater is not a problem. They had already worked out that infra-red is emitted by rocks and coldwater fishes despite what I see the naysayers are telling you. This is quite obvious really. While fish are cold blooded their activity expends energy and if the fish is to stay cold blooded and not heat up from that energy, it has to lose the heat generated by its activity by convection, conduction and radiation - as there is thermal resistance between the fish and the water there is a temperature gradient ie the fish is warmer than the water and so its radiation will be detectable against the background of the water. Similarly for rocks with them getting their heat energy from the natural cooling of the earth and the thermal resistance between them and the sea will enable them to be "seen" against the background of the sea.

The team have specially asked me to rebuke Brendan over his contrary views on this as they feel that he having a scientific background, these things should have been perfectly obvious to him. They can only assume that he was trying to take advantage of you so that he could dump his forward looking sonar onto you.

We all here think that your proposal has a great deal of merit and as others have said will also detect whales and submarines, and of course, human swimmers which raises the possibility of your idea's use for MOB recoveries. For that latter reason we are proposing that all yachts should carry your system.

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[Colin_S]

Here you go Jimi, whack a bid in on <A target="_blank" HREF=http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=1294&item=2498005532&rd=1>this</A>. If you get it and spot any cod, give us a shout and I'll come running, rod in hand!

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[T_S]

Well after the Ships_Cat post it looks like we are all treading water!. I have to say perhaps Jimi's idea was a good one after all!

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[BrendanS]

John,

I do believe your team had at the celebratory bottle of whisky far too soon.

While I congratulate your team on their work with the fourier transformation, the Fourier transformation is not appropriate for this task

[urlhttp://en.wikipedia.org/wiki/Fourier_transform[/url]
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In terms of signal processing, the transform takes a time series representation of a signal function and maps it into a frequency spectrum, where ù is angular frequency. That is, it takes a function in the time domain into the frequency domain; it is a decomposition of a function into harmonics of different frequencies.

When the function f is a function of time and represents a physical signal, the transform has a standard interpretation as the spectrum of the signal. The magnitude of the resulting complex-valued function F represents the amplitudes of the respective frequencies (ù), while the phase shifts are given by arctan(imaginary parts/real parts).

However, it is important to realize that Fourier transforms are not limited to functions of time, and temporal frequencies. They can equally be applied to analyze spatial frequencies, and indeed for nearly any function domain.
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With due respect, I'd suggest they have been idling their time and are messing about, and giving you information of a highly scientific nature that is outside their level of competence. Rocks submersed in water do not radiate heat from background radiation unless in thermal clines (such as seen in NZ, but not in the thermally stable locations such as the Solent)

Yours humbly but in disgust

Brendan

PS, the fish finding capabilities your team have commented on do have some slight possibility of working, though conventional fish finders have taken off and sold in the mass market for very good reason.

PPS, I'd fire the team. Their work at Cern on non related galvanic matters has been shown to be fraud. Crewgirls father worked there, and he states categorically that they have never been on site.

<hr width=100% size=1>Me transmitte sursum, caledoni

 

[Ships_Cat]

Have been practicing on the goldfish in the tank here - been a bit slow cos we have a Ships_Budgie flapping around now.

Anyway, the goldfish seem to be very strong emitters in the orange part of the spectrum so working on an infra yellow camera for testing on them.

John



<hr width=100% size=1>I am the cat but I am only 6.