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A Map Showing Every Cargo Ship

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Re: A Map Showing Every Cargo Ship

#41

Post by espadrine »

roshanj wrote: post #35
kirrent wrote: post #7

Earlier quoted context omitted.

Every ship within range of an AIS receiving station. There are deadspots far out and see and behind obstructions.

Yep, terrestrial AIS receivers can only receive messages from ships that are less than ~50 nautical miles off the coast. Further out than that and you need satellite-based AIS data. (I'm an engineer at Spire, we've launched a constellation of nanosatellites that does exactly that: https://spire.com/products/sense/ )

The website is extremely clear. I am wondering a few further things.

What network design is used to communicate between the satellites? I presume that they don't all go at the same speed in the same direction, so the network layout must be flexible, right?

Also, what is their size? You called them nanosatellites, can they really be a hundred nanometers big? How are they powered, and how are they put out of commission?

Re: A Map Showing Every Cargo Ship

#43

Post by ChoHag »

sitharus wrote: post #14
cjslep wrote: post #8

A couple of observations I thought were interesting: Very few ships travel around the southern tip of South America A corrupted data point sends it flying across Russia and into Southern Europe. A lone ship travelling to Svalbard. Multiple ships travelling in rivers deep into Russia. Control of the nine-dash-line area would yield huge economic influence to the controller.

The southern tip of South America is known as Cape Horn ( https://en.m.wikipedia.org/wiki/Cape_Horn ). It's an unpredictable and dangerous area, hence the popularity of the Panama Canal. Russia is huge, hence a lot of river shipping. Control of the seas would bring a lot of influence, hence the British control of Gibraltar and the complex history of the Suez Canal.

> Control of the seas would bring a lot of influence, hence the British

You can stop there.

Re: A Map Showing Every Cargo Ship

#44

Post by newscracker »

knowaveragejoe wrote: post #31
em3rgent0rdr wrote: post #26

"Burning massive quantities of bunker fuel. The result is a huge amount of CO2...commercial ships produce more than a million tons of CO2 every day." Narrator is unnecessarily alarmist here, and sounds like we should be concerned about the contribution of cargo ships to the greenhouse. I would say we should celebrate the shipping industry for being so much more beneficial to humanity per unit of CO2.

I don't see how it's alarmist to note the fact that they are by far and away one of the largest contributors to greenhouse gasses as a group. I think they could do better, and we wouldn't pay that much more as consumers for a lot of the goods, unless the biggest overhead really _is_ with shipping.

> they are by far and away one of the largest contributors to greenhouse gasses as a group

Not sure what you mean by "group", but animal agriculture beats all transportation (road, sea, air) combined when it comes to greenhouse gases and the greenhouse effect. There are a few different sources from the UN on this (plus some other sources with even higher numbers).

Re: A Map Showing Every Cargo Ship

#45

Post by roshanj »

espadrine wrote: post #41
roshanj wrote: post #35

Earlier quoted context omitted.

Yep, terrestrial AIS receivers can only receive messages from ships that are less than ~50 nautical miles off the coast. Further out than that and you need satellite-based AIS data. (I'm an engineer at Spire, we've launched a constellation of nanosatellites that does exactly that: https://spire.com/products/sense/ )

The website is extremely clear. I am wondering a few further things. What network design is used to communicate between the satellites? I presume that they don't all go at the same speed in the same direction, so the network layout must be flexible, right? Also, what is their size? You called them nanosatellites, can they really be a hundred nanometers big? How are they powered, and how are they put out of commission…

Correct, our constellation uses several different types of orbits to achieve global coverage. The satellites don't communicate directly with one another but rather through a globally distributed network of groundstations. When a satellite passes within view of one of our groundstations we are able to downlink the AIS data which then gets processed and delivered to customers.

Ah yes! I think the term "nanosatellites" is a bit confusing--it refers to satellites between 1 and 10 kg (https://en.wikipedia.org/wiki/Miniaturized_satellite#Nanosat...). Ours are 3U cubesats so they are about 30cm long. Much bigger than a hundred nanometers!

They have solar panels which are used to charge batteries, and since they are in low-earth-orbit they will eventually de-orbit and burn up on reentry after several years. The FCC actually requires that cubesats re-enter the atmosphere within 25 years.

Re: A Map Showing Every Cargo Ship

#46

Post by billforsternz »

billforsternz wrote: post #6

I don't know if it's a quirk of my desktop/Chrome setup but I cannot resize it to reveal possibly the most dynamic trade routes in the world around Japan and Eastern China. Disappointing.

For the record, I am an idiot who couldn't figure out how to click and drag.
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