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Why Is It So Difficult to Map the Ocean?

nautil.us

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Re: Why Is It So Difficult to Map the Ocean?

#51

Post by sn00tz00t »

sn00tz00t wrote: post #50
bradrn wrote: post #30

I do research on oceanic lidar. The basic problem is that light is absorbed and scattered by water, to a far greater extent than it is by air. Thus, even though we have no problem seeing through hundreds of kilometres of air, even a kilometre of water is sufficient to filter out nearly all light [0]. In practical terms, this restricts the ability of lidar systems to detect features underwater. As a general rule of th…

how are bathymetric maps made? if i go to google maps i can see the ocean floor in low res - is that done by satellites? i remember trying to find data of a particular area (near azores) using NOAA maps and all i found was some sort of compendium maps made by different vessels across the years mashed together in a hodge podge of resolutions life sounds rough for ocean floor researchers lmao

oh i read the article, its measurements of gravity wew

Re: Why Is It So Difficult to Map the Ocean?

#52

Post by deepakhj »

gleglegle wrote: post #34
nabla9 wrote: post #27

If you have 100 ocean survey ships scanning the ocean floor 24/7 moving 6 knots with 1 km wide side scan sonar, it takes over 900 years to map all oceans.

10,000 autonomous ships to do it in 9yrs?

https://www.saildrone.com/solutions/ocean-mapping

Re: Why Is It So Difficult to Map the Ocean?

#53

Post by citrin_ru »

dylan604 wrote: post #13
RcouF1uZ4gsC wrote: post #6

I bet the US Navy has classified ocean floor maps that are far beyond those available to the public. Knowing the ocean floor better than your opponents is likely to be a big advantage when playing the various cat and mouse games with attack and ballistic missile subs that the US and the Soviet Union played for decades.

Any ship using sonar to map the floor would not be able to do so in secret. The only hope it would have would be to take advantage of just how vast the ocean is. However, sound carries a long long long way, and it would be very difficult to have a ship doing this in secret. Any opfor ship could just tail behind the ship and passively listen to the same signal and generate their maps in secret.

The ship will not go in secret but the resulting map can be kept in secret if military decides it makes sense.

Re: Why Is It So Difficult to Map the Ocean?

#54

Post by Arech »

checker365 wrote: post #39
nabla9 wrote: post #27

If you have 100 ocean survey ships scanning the ocean floor 24/7 moving 6 knots with 1 km wide side scan sonar, it takes over 900 years to map all oceans.

Could I know your formula? ocean : 361,000,000(km2) 6knots: 11.1km/h 361,000,000/(24*365) = 41,096(km2/day) 41,096/11.1 = 3,702 so, 100 ships take 37years? Thank you, klaus23!

Did it ever occur to you that you take a square kilometer as a linear kilometer in your calculation?

Re: Why Is It So Difficult to Map the Ocean?

#55

Post by dylan604 »

citrin_ru wrote: post #53
dylan604 wrote: post #13

Earlier quoted context omitted.

Any ship using sonar to map the floor would not be able to do so in secret. The only hope it would have would be to take advantage of just how vast the ocean is. However, sound carries a long long long way, and it would be very difficult to have a ship doing this in secret. Any opfor ship could just tail behind the ship and passively listen to the same signal and generate their maps in secret.

The ship will not go in secret but the resulting map can be kept in secret if military decides it makes sense.

Again, you miss the point that while they might want to make it secret, anyone following the mapping ships can secretly have a copy of those same maps.

Re: Why Is It So Difficult to Map the Ocean?

#57

Post by antifa »

dylan604 wrote: post #55
citrin_ru wrote: post #53

Earlier quoted context omitted.

The ship will not go in secret but the resulting map can be kept in secret if military decides it makes sense.

Again, you miss the point that while they might want to make it secret, anyone following the mapping ships can secretly have a copy of those same maps.

Sounds harder than just making your own maps tbh.

Re: Why Is It So Difficult to Map the Ocean?

#58

Post by mierz00 »

Arech wrote: post #54
checker365 wrote: post #39

Earlier quoted context omitted.

Could I know your formula? ocean : 361,000,000(km2) 6knots: 11.1km/h 361,000,000/(24*365) = 41,096(km2/day) 41,096/11.1 = 3,702 so, 100 ships take 37years? Thank you, klaus23!

Did it ever occur to you that you take a square kilometer as a linear kilometer in your calculation?

Don’t the ships have a kilometre wide sonar scan? Therefore traveling 1 kilometre counts as scanning 1 kilometre squared.
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