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Author Topic: Google Earth Coordinates / .kmz files for the Earhart Project  (Read 49686 times)

Heath Smith

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #30 on: March 11, 2012, 03:46:04 PM »

Erik,

Thanks for the update I appreciate it. This is very interesting as it does not appear that the Itasca spend a great deal of effort where they said that the Electra went down.

I have attached the area where Itasca told the Navy where they thought AE and FN might be found some 14 days after the event. On a side note I recently watched a documentary that suggest that the currents were not well understood back then and they were 5 times faster than thought during the original search. According to the documentary they were searching in all the wrong areas after the initial search on the 2nd of July.

Have you been looking at any Sonar data around Howland? Do you happen to have any GE files for where Nauticos has been searching? I have looked over the Waitt Institute Sonar data which is interesting if you want to look over their sonar data. Even with that resolution it would probably be very difficult to spot the Electra. They felt confident that if it were there they would have spotted it in the data.

Looking within GE around Howland there appears to be several large swaths of sonar data around Howland but I cannot find the source? This must have been given to the public domain but I cannot find the source data. I checked in Geomap but did not find the data there.
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Erik

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #31 on: March 11, 2012, 07:16:49 PM »

Heath,

Thanks for those links.  The GeoMap application is quite interesting.  I saw that area where they were talking about 14 days later too.  Was just about ready to create it myself.  Thanks.

Have you been looking at any Sonar data around Howland? Do you happen to have any GE files for where Nauticos has been searching? I have looked over the Waitt Institute Sonar data which is interesting if you want to look over their sonar data. Even with that resolution it would probably be very difficult to spot the Electra. They felt confident that if it were there they would have spotted it in the data.
Attached is .kmz for the Nauticos search area.  I agree, it would be hard to spot a plane.  Even if the plane went down nearyby, there are arguments that the fuel tanks would have been enough to allow the plane to remain buoyant even submerged.  So, even then the plane may have 'floated' (even under water) quite a ways from where it hit water, if Waitt is correct.

Looking within GE around Howland there appears to be several large swaths of sonar data around Howland but I cannot find the source? This must have been given to the public domain but I cannot find the source data. I checked in Geomap but did not find the data there.
I saw those swaths too.  The first thing that came to mind was organizations who maintain trans-oceanic communication cables may have done the swaths of sonar.  Some of them go thousands of miles!


Attached is the .kmz for the Nauticos search area.
« Last Edit: March 11, 2012, 07:26:22 PM by Erik »
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Heath Smith

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #32 on: March 11, 2012, 08:07:57 PM »

Erik,

Thanks for the info. Please let me know when you have more GE files to share and I will do the same.

Yes, that is exactly the swath that I was looking at. I spent some time searching but could not find the source of the data. While it is a slim swath and the probability would be quite low that they just happened to pass over the Electra it might be fun to scan the data anyway if it can be obtained for free. If I find anything more about it I will pass it on.

Here is something interesting regarding Howland and perhaps Baker:

The Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Howland Island

While the image resolution is too low to be useful for finding a plane perhaps they have higher resolution data that could be displayed in GeoApp or a similar application. It is too bad they did not scan the area around Gardner Island.
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Erik

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #33 on: March 12, 2012, 03:48:29 PM »

While it is a slim swath and the probability would be quite low that they just happened to pass over the Electra it might be fun to scan the data anyway if it can be obtained for free.
Ah - I gotcha now....  I missed the whole point of the swaths and bottom sonar imagery.  Heck yeah, we could even start our own "ROV thread" searching for the electra.  he.. he..  :)

Here is something interesting regarding Howland and perhaps Baker:
The Pacific Islands Benthic Habitat Mapping Center (PIBHMC), Howland Island
More good stuff!  Thanks.

Please let me know when you have more GE files to share and I will do the same.
Sure thing.  Do you know about GE 'underwater mode'? 
Tools -> Options -> Show Terrain
View -> Water Surface
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Heath Smith

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #34 on: March 12, 2012, 04:05:33 PM »

Eric,

Thanks for the files. I did not know there was a way to turn off the water surface but I did accidentally fly under the water once and looked around Howland and Gardner. You have to love GE. Now if we could just get a hold of some interesting data and sift through it.

Side scan sonar is definitely interesting. If it were me, I would go for the side scan before bothering with remote submersibles and cameras around Gardner. If there is a plane, boat, or anything else, you would be able to find it.

Check out this side scan sonar of a B-17 that crashed off of Corsica, an Island off the West Coast of Italy.

Attached are a few interesting side-scan sonar images of various ship and plane wrecks. Click the radio button for each scan and it will download the image from the net. I would really like to get my hands on a side-scan for use in the lakes here in and around Michigan.
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Erik

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #35 on: March 12, 2012, 04:48:23 PM »

That's some cool stuff.  I would imagine the argument against the sonar is that the location (and water depth) need to be with certain tolerances.  Too deep water and too uncertain location could be cost prohibitive.  Then again Nauticos did it, over a much larger area.  Any estimate on $$$ for a Nauticos type operation "just" to encircle Gardner once or twice?
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Heath Smith

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #36 on: March 12, 2012, 05:33:02 PM »

As you say, the depth is a concern. For 200-300' you could probably find a unit off the shelf for a reasonable price. You could probably do some decent maps on the shelves with one of those. Beyond that depth you would need something more sophisticated. I am not sure how deep the tow behinds can operate but Nauticos is probably using those sophisticated autonomous subs that would be very expensive.

Maybe if Nauticos does end up back at Howland they could be contracted to make a pass around Gardner while they are out in that vicinity in the Pacific.

Here is a nice one that can operate to 6000M depth.

They even offer rentals for that unit here.
« Last Edit: March 12, 2012, 05:39:31 PM by Heath Smith »
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Heath Smith

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #37 on: March 18, 2012, 07:12:13 AM »


Erik,

I was thinking a bit more about the search area covered by the Itasca. If we consider that the crows nest on the Itasca was say about 120ft (just a guess), they observers up there could see about 15.3SM to the horizon. Looking at the search area out to 120NM, they probably did have a fair coverage assuming about a 30SM swath where they did travel. I thought that I could perhaps just increase the line thickness to accurately reflect this but there is a maximum allowed value of 100 or so, not nearly enough. Do you know of any way to turn the lines to in to polygons? It would be interesting to see in GE that maximum possible area that was searched. Thanks in advance.
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Erik

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #38 on: March 19, 2012, 08:18:17 PM »

Heath,

Funny you mention that.  I too noticed a pattern to the search distance.  If you compare the search areas where they tracked back-and-forth on a zig-zag pattern, its roughly a 25-30 mile swath between the lines.  So, yes a 15 mile offset seems about right.  And just as importantly, that they were aware of that distance during the operation.

I would have to say though that spotting a floating airplane, raft, or person floating in the water is going to exponentialy decrease the further away you get.  So a polygon would give us a rough estimate, a better model would be a "heat map" showing infinte ranges of decreasing values the further away.

I am working on that now.  Small glitch with GE exporting polygons on the 180 degree dateline.  I've got a fix (i think).  Hang tight.

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Heath Smith

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #39 on: March 20, 2012, 03:51:31 AM »


Erik,

I am looking forward to what you come up with. Another factor we might want to consider is whether the given areas were searched during daylight or nighttime hours. If they did not have flares for example, how would Itasca expect to see them at night? Perhaps there would be a way to code that in to your color scheme somehow.

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Jeff Palshook

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #40 on: March 25, 2012, 07:05:40 AM »

Heath & Erik,

In Reply #31 of this thread, the graphic you show depicting the Nauticos search area is actually the search area from the Waitt search.

There have been to date four deep-water searches for the Electra, conducted in the general vicinity of Howland Island:  (1) Dana Timmer in 1998 (or it might have been 1999), (2) Nauticos in 2002, (3) Nauticos + Waitt in 2006, and (4) Waitt in 2009.  The first three of those searches used towed systems.  Only Waitt 2009 used autonomous underwater vehicles (AUV's), 2 REMUS-6000 vehicles ("6000" refers to the maximum operating depth of the vehicles, 6000 meters), built by Hydroid, a commercial spin-off from Woods Hole Oceanographic Institute (WHOI) which has developed over many years the very successful family of REMUS AUV's.  Hydroid was purchased by Kongsberg Marine several years ago.  Waitt owns the two REMUS-6000 AUV's but has WHOI/Hydroid operate them; Waitt does not have the in-house expertise or experience to operate these vehicles.

Only Waitt has made public any of its data, including the area searched.  Nauticos has not made is data public and presumably will not do so unless and until it finds the Electra.

The waters around Howland Island approach 18,000 feet deep.  In the deep-ocean search business, 20,000 feet -- which is approximately 6000 m -- is called "full-ocean depth".  Twenty-thousand feet to the deepest point in the oceans (approximately 36,000 feet at the bottom of the Marianas Trench) is called "ultimate ocean depth".  For comparison, the TITANIC lies at about 12,000 feet deep.

Getting to 12,000 feet or 18,000 feet is no easy feat.  There are literally only a handful of systems in the world, towed and AUV, which can reach full-ocean depth.  And there is an even smaller handful of companies in the world which own and operate these complex systems.  A significant part of the cost of hiring one of these companies and one of these systems (again, towed or AUV) is the cost of the group of technicians which operates and maintains the system.  A key part of this group is own or more individuals with expertise in analyzing and interpreting side-scan sonar data.  Side-scan imagery sometimes looks a lot like a photograph, and there are some similar principles involved in the two different imaging schemes; but side-scan is really a different beast which requires specialized training, skills, and experience to accurately interprete it.  "Reading" a side-scan image often is not easy, it's not like looking at a photograph.

Towed systems are the older technology, but they are not that much less complex overall compared to a full-ocean depth AUV.  The cost for "hiring" a towed system is probably about the same as the cost for an AUV system with similar capabilities.  Towed or AUV, each has its own set of unique advantages and disadvantages compared to the other system.  The deep-ocean search business is slowly moving toward AUV's, but towed systems will likely be around for quite some time yet.  The number of full-ocean depth AUV's available to the "private" or commercial sector (i.e AUV's outside of the navies of the world and outside of basically government-owned/operated oceanographic institutions) is tiny.  Basically there are the two Waitt REMUS-6000 vehicles, there is one REMUS-6000 which I think is owned and operated by a French oceanographic institute, and there is one or two Hugin AUV's built, owned, and operated by Kongsberg Marine.  That's it as far as I know for full-ocean depth AUV's in the private sector.

The deep-water oil and natural gas industry drives the demand for AUV's.  So far this industry has had no need to operate much below 12,000 or 15,000 feet.  This is why there are so few full-ocean depth AUV's available in the commercial world.

Any of these full-ocean depth systems, towed or AUV, has a side-scan sonar very much capable of detecting Earhart's Electra (again, assuming the side-scan data the system collects is analyzed and interpreted by a side-scan expert), if it does happen to lie on the ocean floor somewhere near Howland Island.

Traditionally, side-scan sonar systems have been very expensive (even systems which don't have to operate anywhere near full-ocean depth).  This is because underwater search has always been a niche industry with a small number of users, and because the equipment has been high-tech.  The large research and development costs associated with these systems, coupled with relatively few commercial customers interested in buying them, has made the per unit cost of a side-scan system very high.

The situation has been changing in the last few years.  Sport and commercial fisherman (as well as small government interests such as underwater search and rescue teams,  have always been interested in having a side-scan sonar capability but couldn't afford it.  With the advances electronics and the general decreasing costs of electronic components, the manufacturers of marine electronics have started making side-scan sonars units which are within the price range of the recreational boater/fisherman.  I know Humminbird and Lowrance now are selling such systems.  These are hull-mounted systems designed to be used in very shallow water.  I don't know what these units cost, but I would guess they sell for around $5000 per unit.  If you're interested, you might want to check out the Humminbird 1198c SI or the Lowrance HDS 10.
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Jeff Palshook

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #41 on: March 25, 2012, 07:07:30 AM »

Erik & Heath,

Your guess about the height of eye provided by ITASCA's crow's nest is a good one, but a little high.  I used to have access to a set of drawings of the ITASCA.  I scaled dimensions on these drawings to get an estimates of various heights (bridge wings, main deck, "crows nest", etc.) on the ship.  I don't have easy access to those drawings any more, but I did keep some notes on some of the dimensions I measured.  I came up with 86 feet for the height of the base of the "crows nest" above the waterline.  Assuming a sailor of average height standing on this platform, I think you could reasonably at 5 feet to this for a height of eye of about 94 feet.

Using the standard formula for distance to the horizon (Distance to horizon, in nautical miles, = 1.144 *sqrt(height of eye, in feet)), height of eye of 94 feet gives a distance to the horizon of 11.1 nm.

However, I think the actual distance one could see two heads bobbing in the ocean, or even two people in a life raft, would be a lot less than 11 nm.  I used to be a U.S. Navy submarine officer, spent lots of time looking out a periscope, more limited time looking at objects from the bridge of a submarine.  (Modern nuclear submarines don't spend much time on the surface.)  Several years ago I asked a current professional mariner for his estimate on how far away you could see a life raft.  His estimate was 3 nm under "average" conditions.  Obviously, the answer is going to depend on the specific conditions.  If the occupants of the life raft had a mirror or some other shiny object, and if it were sunny, sun glint off the shiny object could significantly increase this "average" detection distance.

My own guess based on all of this is that 5 nm is probably a generous estimate for the maximum detection distance under typical sea and sky conditions.
 
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Heath Smith

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #42 on: March 25, 2012, 07:12:39 AM »


Jeff,

Thank you for all that detailed information.

Are your estimates for spotting a raft based on the use of binoculars or the naked eye? Do we know if they had binoculars or spotting scopes up in the crow's nest?

Thanks!
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Jeff Palshook

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #43 on: March 26, 2012, 01:48:21 AM »

Heath,

My 5 nm estimate assumed use of standard 7 X 50 binoculars (i.e., 7X magnification), which is what I think I used on the bridge back in my Navy days.  (They might have been slightly higher magnification now that I think of it, whatever the next standard size up from 7X is.)

After posting my 5 nm estimate, I have had some 2nd thoughts about it for the case of looking for a life raft using binoculars.  I'm going to seek another opinion from one ex-navy officer friend, will let you know if this changes my estimate.  I may also try to back some time to do a simple visual simulation of the life raft case.

I think an ITASCA lookout placed in the crow's nest would definitely have been given a pair of binoculars to use.  Again, my experience on Navy surface warships was very limited (essentially to a couple of midshipman training cruises), but what I recall is that a Navy surface warship stationed at least three lookouts during normal underway steaming -- one lookout on each bridge wing (port and starboard) and one lookout at the stern looking astern of the ship.  Each of these lookouts had a pair of binoculars.  The Officer of the Deck (OOD) on the bridge also had a pair of binoculars available for his use.  And I'm pretty sure there was another pair of binoculars on the bridge reserved for the captain's use.  The ship probably had a few extra pairs of binoculars on board to cover contingencies.  I don't know for sure that the ITASCA used the same watch organization of lookouts back in 1937, but I assume what I've described was a standard set of lookouts that had been used by Navy ships for many years before I saw it.

My point with the number of binoculars on board is that there should have been extra binoculars available to use in the crow's nest during ITASCA's search for Earhart.  Who knows, there may also have been some pairs of personally-owned binoculars on board.  If there were, I imagine these would have been pressed into service as well.

My opinion is that Warner Thompson, CO of ITASCA, was a very competent seaman and no fool.  He was fully aware of the gravity of the situation he was in when Earhart failed to arrive at Howland.  Most importantly, he knew there were two lives at stake.  And he knew one of those two was a public celebrity, and he was the guy "on watch" when she went missing.  I think Thompson did the very best he could, with the information he had at the time, to find Earhart and Noonan.  He would have taken whatever actions he felt would increase the chances of finding them.  This almost certainly would have included putting a lookout, with binoculars, in the crow's nest.
 
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Gary LaPook

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Re: Google Earth Coordinates / .kmz files for the Earhart Project
« Reply #44 on: March 26, 2012, 02:56:47 AM »

Erik & Heath,

Your guess about the height of eye provided by ITASCA's crow's nest is a good one, but a little high.  I used to have access to a set of drawings of the ITASCA.  I scaled dimensions on these drawings to get an estimates of various heights (bridge wings, main deck, "crows nest", etc.) on the ship.  I don't have easy access to those drawings any more, but I did keep some notes on some of the dimensions I measured.  I came up with 86 feet for the height of the base of the "crows nest" above the waterline.  Assuming a sailor of average height standing on this platform, I think you could reasonably at 5 feet to this for a height of eye of about 94 feet.

Using the standard formula for distance to the horizon (Distance to horizon, in nautical miles, = 1.144 *sqrt(height of eye, in feet)), height of eye of 94 feet gives a distance to the horizon of 11.1 nm.

However, I think the actual distance one could see two heads bobbing in the ocean, or even two people in a life raft, would be a lot less than 11 nm.  I used to be a U.S. Navy submarine officer, spent lots of time looking out a periscope, more limited time looking at objects from the bridge of a submarine.  (Modern nuclear submarines don't spend much time on the surface.)  Several years ago I asked a current professional mariner for his estimate on how far away you could see a life raft.  His estimate was 3 nm under "average" conditions.  Obviously, the answer is going to depend on the specific conditions.  If the occupants of the life raft had a mirror or some other shiny object, and if it were sunny, sun glint off the shiny object could significantly increase this "average" detection distance.

My own guess based on all of this is that 5 nm is probably a generous estimate for the maximum detection distance under typical sea and sky conditions.
The three mile estimate comes close, but rather than guessing at it why not use the data developed by the professionals. I have attached excerpts from the National Search And Rescue Manual with the data you need.

The important concept is sweep width (W) which is the width of the patch of ocean covered as the ship moves along. The table shows that with 20 NM visibility for a one man raft the W is 3.7 NM and for a 4 man life raft it is 5.0 NM. What this means is that you have an 80% probability of detection (POD) for anything within 1.85 NM or 2.5 NM on each side of the vessel. If you cover the same path a second time then the POD goes up to 97%. This is not the maximum detection range which is something slightly greater, see diagram. If you space (S) the search pattern legs to be separated by 1 W then the coverage factor (C) will also be 1 which produces the POD I just mentioned. If you space the legs at half of W then the coverage factor becomes 2 and the POD for one pass goes up to 99%. If you space the legs twice as far apart as the W then the coverage factor goes down to 0.5 and the POD for one pass goes down to 48%, 2 passes 71%, 3 passes 85%, etc.

With a mirror the W is 5.0 NM and at night for a Very flare it is 8.0 NM.

gl

« Last Edit: March 26, 2012, 04:20:36 AM by Gary LaPook »
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