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Old 18-01-2012, 11:14   #151
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Originally Posted by btrayfors
I'm sorry to say that you're WAY out of your depth, my friend. Give it up. Stick to something you know something about, like electronics.
Right. I believe what NOAA themselves write about how they do it over what you are telling us here Bill, sorry. It would also help when you tone down a bit.

Also, pot shots at NOAA?! Are you serious? You do the same to about every other hydrographic office which would include ones like the Dutch and English etc. that mapped the world long before there was a USA. I know, you said it in such a political way that it opens a path to denying it and blaming me for it again. So if you believe that your beloved NOAA is so on top of things, why don't you exactly know how they produce charts?

Love it how you dare to write "with respect" under that; does that change all you wrote above that?

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Old 18-01-2012, 11:19   #152
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Re: Why Integrate the Autopilot ?

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Originally Posted by sidmon View Post

There is a largely unrecognized human factors problem here. And that is the beautiful presentations on those screens WILL lull the unsuspecting -or less than careful- into trusting them implicitly.

Its happened in enough aircraft cockpits, and ship's bridges to deny that the problem is something more than simply idiots at the helm.
Yes -- I think that's actually at the heart of the matter. And I think that is what happened to the Costa Concordia.

The "beautiful representation" masks the underlying inaccuracy of the data. The problem is that when you change the scale of the chart plotter, everything represented retains the same appearance of being resolved and defined, the hard lines stay hard, although the accuracy of what is represented changes dramatically as the scale is increased. You don't have this problem with paper charts because they only have their one scale -- so you can get an orientation about the margin or error -- the circle of confusion, to use an analogy to optics -- with paper charts. You easily lose this orientation with a chart plotter.

So Schettino said publicly the rock should have been 100 meters away! Or 50 meters away! Well, what did he think the basic accuracy of his charts were? What margin of error was he leaving himself, navigating to a point 50 meters from known obstructions? I think he was deceived by the "beautiful representation" of the chart plotter and forgot the underlying margin of error of the system he was using.

I guess we have to admit that he was incredibly reckless, yet on the other hand, how many of us, no matter what good pilots we are, are lulled into that sense of being in a video game, while watching our plotters?

It's our failure not to be acutely aware of this, but maybe the tools themselves could be better -- some kind of icon or representation showing the change in the likely error as the scale of the plotter is changed -- that would really be helpful for that orientation which we so much need.

If anyone still doesn't understand what I'm talking about -- imagine taking it to the absurd: We zoom in our plotters so that one meter of coastline is represented along the left side of the plotter. There is STILL a hard line there, and that line is in a precise position, although the representation is absurd -- the data does not show where the coastline is to a centimeter. The representation on the plotter of a vector chart at that scale is totally absurd. To a lesser degree, that is actually what we have on our plotters.
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Old 18-01-2012, 11:26   #153
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Re: Why Integrate the Autopilot ?

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Originally Posted by s/v Jedi View Post
I agree with Steve that they are exactly he same. Sometimes companies like Jepessen charter survey vessels and get an advantage for some specific area that others don't have. I saw them doing that with C-Map charts brought out in 2006 for some areas in Colombia and Panama that were uncharted or very inaccurate before that. I just ordered a new chartkit from them and am wondering about any changes to be found.
Sure the cartographic database is digitized. All that was started by what was then known as DMA in the early '90s.

And there were complaints then about how "featureless" charts became too in regards to detailed topographic information.

Sure is interesting that Jepp would spend that kind of money to survey the northern coast of South America, when their chart data is years out of date in Lake Michigan (Meigs Field has been gone for years now)

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Originally Posted by s/v Jedi View Post
About the satellites: although hydrographic offices start using sme satellite data, I am not saying that they only use satellite... not at all! I am saying that more accurate data exists but they don't have access to it.
Of course satellite data has been used in cartography since the '60s (when it was highly classified). But there is no "magic" data being kept from you.

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Originally Posted by s/v Jedi View Post
Our charts are much less accurate than our GPS. So why does the military need a more accurate positioning? Right, because they have charts that are more accurate than the public GPS accuracy!
You would be amazed at the unknowns in that world Nick. The laws of physics always apply...As does the tyranny of a lack of resources.

Just sayin'

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Old 18-01-2012, 11:45   #154
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Re: Why Integrate the Autopilot ?

Might add that I first started pondering this "how could it happen?!?!?!?" when this happened:

The same factors were at play. While there ample information to make the right call (I had been in the same spot months before doing the same job)...All were focused on what was then a "star trekkian" big screen in Combat that was displaying an improperly categorized symbol.

It was all too pretty and compelling NOT to be believed. So I call this syndrome, "The Vincennes Effect"

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Old 18-01-2012, 12:22   #155
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Originally Posted by sidmon
Nick, NO satellite can "see" beyond just a few meters depth below the sea surface and derive an accurate depth.
I know I am snotty because I'm told so now and then here on CF, but I always try to bring correct information and include references, citations etc. I can be wrong too and don't mind to hear that at all, if explained why I am wrong with references and citations

Now here is NOAA explaining how satellites measure depths beyond a couple of meters. There are many more resources available, I just selected NOAA to keep things tight. http://www.ngdc.noaa.gov/mgg/bathyme...d/explore.HTML

Keep in mind there are many kinds of satellites, not just ones that take pictures. The document above also shows that much is classified because it mentions data that was de-classified. It would be very naive to think that there are no classified charts that are more accurate, let alone data that is more accurate. They normally only declassify information that is obsolete because there is something better.

The sub colliding is much like the cruiseship disaster, human error. The airliner shot down by the US by accident was a shameful incident but it was done with heat seeking missiles and I don't know how that relates to charts and their accuracy...
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Old 18-01-2012, 12:57   #156
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Re: Why Integrate the Autopilot ?

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Originally Posted by s/v Jedi View Post
I know I am snotty because I'm told so now and then here on CF, but I always try to bring correct information and include references, citations etc. I can be wrong too and don't mind to hear that at all, if explained why I am wrong with references and citations

Now here is NOAA explaining how satellites measure depths beyond a couple of meters. There are many more resources available, I just selected NOAA to keep things tight. Exploring the Ocean Basins with Satellite Altimeter Data

Keep in mind there are many kinds of satellites, not just ones that take pictures. The document above also shows that much is classified because it mentions data that was de-classified. It would be very naive to think that there are no classified charts that are more accurate, let alone data that is more accurate. They normally only declassify information that is obsolete because there is something better.

The sub colliding is much like the cruiseship disaster, human error. The airliner shot down by the US by accident was a shameful incident but it was done with heat seeking missiles and I don't know how that relates to charts and their accuracy...
Thanks for that NOAA link Nick. But note that they are talking about sea SURFACE anomalies detected.

Bottom line. Satellite sensors - of any stripe- CANNOT be used to derive water depths with any accuracy.

Sorry, but its that whole laws of physics thing.

The San Francisco (cited link bac aways in this thread) was due to COMPLACENCY by the Nav Team.

I have had access to some of that classified data to which you speak in the past...You would be most definitely underwhelmed Nick.

The missile in question was a radar guided missile called a SM-2, not a heat seeker.

How all that relates is in the concept of how a very compelling display of data...be it an electronic battle display on a guided missile destroyer; a CDU in 757; or an ECDIS on the bridge of a cruise ship... is so easily accepted as delivering immutably correct information, when in fact what is there can be glaringly inaccurate in retrospect.

And how such displays of data can foster a dangerously insidious sense of complacency by their users.
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Old 18-01-2012, 13:31   #157
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Quote:
Originally Posted by sidmon

Thanks for that NOAA link Nick. But note that they are talking about sea SURFACE anomalies detected.

Bottom line. Satellite sensors - of any stripe- CANNOT be used to derive water depths with any accuracy.

Sorry, but its that whole laws of physics thing.

The San Francisco (cited link bac aways in this thread) was due to COMPLACENCY by the Nav Team.

I have had access to some of that classified data to which you speak in the past...You would be most definitely underwhelmed Nick.

The missile in question was a radar guided missile called a SM-2, not a heat seeker.

How all that relates is in the concept of how a very compelling display of data...be it an electronic battle display on a guided missile destroyer; a CDU in 757; or an ECDIS on the bridge of a cruise ship... is so easily accepted as delivering immutably correct information, when in fact what is there can be glaringly inaccurate in retrospect.

And how such displays of data can foster a dangerously insidious sense of complacency by their users.
Yes satellites look at the surface with radar but that data is used to generate the maps of the seabed deep under that water. This is because the surface shape depends on gravity which depends on the seabed below it.

See this link for more info: http://oceanworld.tamu.edu/resources...apter03_04.htm
For navigational charts, it is used for several things: it determines locations of posible hazards to navigation that can then be checked out by surface ships. It also creates that map of the seabed which is used to accurately interpolate between depth measurements from the surface which "calibrate" that satellite data. This means just a few surface measurements are enough for coverage of huge areas.

The link you provided states it was a heat seeking missile, not a radar guided missile. If you fired that missile, I will believe you of ourse

Complacency.... it was just reported the cruiseship disaster was caused because the captain used eyeball navigation instead of ecdis, radar etc. That is the opposite of the complacency theory that is so lved and often cited by the "eyeballs rule" class of navigators

cheers,
Nick.
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Old 18-01-2012, 14:37   #158
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Re: Why Integrate the Autopilot ?

Looking at the NOAA article I did not get the impression that satellites have removed the need for shipboard surveying but rather their data is complementary. so the gravity maps are the perfect reconnaissance tool for planning the more detailed shipboard surveys.

"
Planning Shipboard Surveys
The satellite-derived gravity grids reveal all of the major structures of the ocean floor having widths greater than 10-15 km (6-9 mi). This resolution matches the total swath width of the much higher multibeam mapping system on a ship (100 m resolution) so the gravity maps are the perfect reconnaissance tool for planning the more detailed shipboard surveys. Scientists aboard research vessels use the gravity grids along with other measurements to optimize their survey strategy; in many cases this is done in real time. The cost to operate a research vessel is typically $20,000 per day so these gravity data have become an essential item. "
Australian Navy still operates its survey vessels surveying more accurately in particular routes through GBR for shipping.
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Old 18-01-2012, 14:42   #159
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Re: Why Integrate the Autopilot ?

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By combining data from echo sounders with data from GEOSAT and ERS–1 altimeter systems, Smith and Sandwell (1997) produced maps of the sea floor with horizontal resolution of 3 km and depth accuracy of 100 m.
Nick, did you read this at the bottom of your linked page. Not something I would like to navigate with.
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Old 18-01-2012, 14:55   #160
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Nick, did you read this at the bottom of your linked page. Not something I would like to navigate with.
I wouldn't want to either But no worries, I don't think their chars were ever sold or navigation

I wonder when the quotes come that say it is used for interpolation like I wrote

ciao!
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Old 18-01-2012, 19:11   #161
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Re: Why Integrate the Autopilot ?

Nick, if satellite sensors could be used in the manner in which you suggest, then the navy would have no trouble at all finding submarines...

But they do. Even little ones close to the surface.

For practical purposes, deriving depths with any precision from satellites is impossible.

Believe it. Or not. (and we know which camp you are in)

As to the whole missile sidebar. I very quickly grabbed a contemporaneous newspaper article that was slam full of inaccuracies. As I said above, I did the same job in the same place a few months before the "Robocruiser" came on station..

But none of that matters for this discussion.

What does is that automated/integrated nav-control systems have ushered in a totally unexpected threat.

And that threat is Complacency.

We are busy fighting it in commercial aviation.

The navy has begun to fight it on their ships after some spectacular mishaps like the San Francisco and Port Royal:



And, now these systems are finding their way onto pleasure craft.

Dollars to donuts the commercial maritime world -especially the cruise ship industry is now going to do something about it.

And also Dollars to Donuts -even with the much less immediate risks associated with relatively shallow draft and light usage patterns- we will be discussing ...

How could this happen?!?!?!?!?

As pleasure craft fall victim to these modern Sirens as well.
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Old 18-01-2012, 20:39   #162
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Re: Why Integrate the Autopilot ?

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Nick, if satellite sensors could be used in the manner in which you suggest, then the navy would have no trouble at all finding submarines...
You must have skipped reading the part that says it took years to complete these scans which by the way were done by the US navy to "satisfy their navigational needs". Submarines tend to move a lot during that time.

Really, why do I need to defend this, read the articles, write to NOAA and the Navy if you think it's wrong

Quote:
For practical purposes, deriving depths with any precision from satellites is impossible.
Yes I believe you said that before and we read that. I also agreed that more data input was needed but that gets ignored because it takes away from the fun of this game of word twisting, I understand

Quote:
Believe it. Or not. (and we know which camp you are in)
Only few here know me well enough to understand that I am in no camp. I will question anybody and everything that sounds not right to me. Only citations and references that make sense that are brought forward help to make a case, not statements about camps I am not in

Quote:
What does is that automated/integrated nav-control systems have ushered in a totally unexpected threat.

And that threat is Complacency.
I do not agree. The threat is clueless people put on stations that require some brains as they have always done. Now let me put something in bold:

The threat is the people that believe that automation makes difficult jobs doable by the clueless masses, as well as people who will fight any modern progress.

So, you missed me telling that the captain of that cruise ship didn't use his integrated nav controls at all? he hit the rocks because he decided his eyeball navigation would do. How Complacent is that?!

ciao!
Nick.
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Old 18-01-2012, 21:46   #163
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Re: Why Integrate the Autopilot ?

Sidmon makes some good points about automation, though the danger is not merely complacency; it's also task saturation, misinterpretation and confusion, loss of situational awareness, etc.

This doesn't tell us much about autopilot modes. Commercial pilots frequently use the integrated "navigation" mode instead of "heading" mode. Fighter pilots rarely use the autopilot. However, they all use complex, integrated systems, and this requires study and practice, prioritization of critical tasks, good habits and procedures, crew communications, etc.

You shouldn't be scared of automation if you learn your system, prioritize your tasks, and pay attention to the "big picture." Don't pile up on the rocks because you were too busy watching the pretty green line on your display...
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Old 19-01-2012, 04:07   #164
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Re: Why Integrate the Autopilot ?

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You must have skipped reading the part that says it took years to complete these scans which by the way were done by the US navy to "satisfy their navigational needs". Submarines tend to move a lot during that time.

Really, why do I need to defend this, read the articles, write to NOAA and the Navy if you think it's wrong



Yes I believe you said that before and we read that. I also agreed that more data input was needed but that gets ignored because it takes away from the fun of this game of word twisting, I understand



Only few here know me well enough to understand that I am in no camp. I will question anybody and everything that sounds not right to me. Only citations and references that make sense that are brought forward help to make a case, not statements about camps I am not in



I do not agree. The threat is clueless people put on stations that require some brains as they have always done. Now let me put something in bold:

The threat is the people that believe that automation makes difficult jobs doable by the clueless masses, as well as people who will fight any modern progress.

So, you missed me telling that the captain of that cruise ship didn't use his integrated nav controls at all? he hit the rocks because he decided his eyeball navigation would do. How Complacent is that?!

ciao!
Nick.
Nick I was long aware of that NOAA effort; you have told me nothing new.

+/- 100m (with ALOT of caveats) IS NOT accurately depicting depths

No matter how you want to portray it...But whatever.

Keep believing that there is magic out there if you wish.

Schettinno:

Schettino, who has said he will cooperate with investigators, says the rocks were uncharted, and his lawyer says Schettino did everything he could to preserve the lives of crew and passengers.


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Old 19-01-2012, 04:16   #165
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Originally Posted by sidmon

My bet still stands that Schettino will blame his electronic charts. And that his career long reliance on them was a significant factor in this accident.
He stated he knew the area well., he has stated he was navigating by sight and he ordered the turn too late.

This is simply not a chart related issue. The captain had previously executed such a close flyby , with agreement of Costa the previous August. The two tracks are remarkably close. But this time again if you compare the tracks , he strayed just a little close to la Scole then before. That was enough to do it.

This isn't about electronic bridges.

By the way I was on the voyager of the sea bridge. They used paper charts all the time.

Dave
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