Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

South Pacific Sandy Island 'proven not to exist'

bbc.co.uk

Post reply on HN
Print view View original

41–49 of 49 posts

Re: South Pacific Sandy Island 'proven not to exist'

#41

Post by LiamMcCalloway »

mxfh wrote: post #25
paulgb wrote: post #14

Earlier quoted context omitted.

I assume it's blacked out because their geospatial data shows that it's land but they don't have satellite data to cover it.

Its seems to exist as an incorrect shoreline in the freely available NOAA GSHHS Shorelines data[1] which digitalglobe[2] uses to crop low-resolution satellite images to be replaced with high-resolution land area imagery, with nothing available for the location this results in the black spot. Landsat[3] never showed anything there, especially at this size. Earliest depiction[4] I found in the short time via oldmapsonl…

Not sure what you mean about SHOM?

Re: South Pacific Sandy Island 'proven not to exist'

#42

Post by wyclif »

chollida1 wrote: post #30
discountgenius wrote: post #29

"...some map makers intentionally include phantom streets to prevent copyright infringements..." Wait, what?

It's a very common thing to put a made up one way street into the map. If your competitor has the same street then it's pretty easy to tell they are "using" your map data. Cisco allegedly did something similar when it suspected Huwei was usign it's source code. They added some minor typos to error messages and then check the Huawei routers and sure enough they had the same mis-spellings. Since no one programs against…

Land surveyor and cartographer here. I just came by to say that while "traps" are common on land maps, in nautical cartography they are not. I don't understand why anybody would reasonably surmise that this is a "trap island" since marine cartographers do not use them.

Re: South Pacific Sandy Island 'proven not to exist'

#43

Post by yen223 »

wyclif wrote: post #42
chollida1 wrote: post #30

Earlier quoted context omitted.

It's a very common thing to put a made up one way street into the map. If your competitor has the same street then it's pretty easy to tell they are "using" your map data. Cisco allegedly did something similar when it suspected Huwei was usign it's source code. They added some minor typos to error messages and then check the Huawei routers and sure enough they had the same mis-spellings. Since no one programs against…

Land surveyor and cartographer here. I just came by to say that while "traps" are common on land maps, in nautical cartography they are not. I don't understand why anybody would reasonably surmise that this is a "trap island" since marine cartographers do not use them.

The full quote from the article covers your concern.

> "A spokesman from the service told Australian newspapers that while some map makers intentionally include phantom streets to prevent copyright infringements, that was was not usually the case with nautical charts because it would reduce confidence in them."

Re: South Pacific Sandy Island 'proven not to exist'

#45

Post by andyjohnson0 »

LiamMcCalloway wrote: post #41
mxfh wrote: post #25

Earlier quoted context omitted.

Its seems to exist as an incorrect shoreline in the freely available NOAA GSHHS Shorelines data[1] which digitalglobe[2] uses to crop low-resolution satellite images to be replaced with high-resolution land area imagery, with nothing available for the location this results in the black spot. Landsat[3] never showed anything there, especially at this size. Earliest depiction[4] I found in the short time via oldmapsonl…

Not sure what you mean about SHOM?

Service Hydrographique et Océanographique de la Marine

http://www.shom.fr/

Re: South Pacific Sandy Island 'proven not to exist'

#46

Post by LiamMcCalloway »

andyjohnson0 wrote: post #45
LiamMcCalloway wrote: post #41

Earlier quoted context omitted.

Not sure what you mean about SHOM?

Service Hydrographique et Océanographique de la Marine http://www.shom.fr/

Sorry, I should have been clearer. What did you think the fact that their maps did not show this island mean?

Re: South Pacific Sandy Island 'proven not to exist'

#47

Post by grecy »

quink wrote: post #40
grecy wrote: post #39

Earlier quoted context omitted.

Yup. Melway is a company that makes excellent street directories for all the major cities in Australia.[1] It came out a while ago that on every single page, there are intentional errors that would help catch someone copying their maps. There was a phone box marked on my street that didn't exist, and a friend's house was next to a street that didn't exist. It gained some attention a while back because it could turn i…

It's entirely likely that it's just outdated data. However, it's not so much a part of a trend of disappearing phone booths, TUSMA is providing government money to Telstra for keeping about 20,000 phone booths active such that all Australians have reasonable access to one.

When the safety issue blew up they asked the company about it and they confirmed the "mistakes" are intentional to catch copiers.

Re: South Pacific Sandy Island 'proven not to exist'

#48

Post by quink »

grecy wrote: post #47
quink wrote: post #40

Earlier quoted context omitted.

It's entirely likely that it's just outdated data. However, it's not so much a part of a trend of disappearing phone booths, TUSMA is providing government money to Telstra for keeping about 20,000 phone booths active such that all Australians have reasonable access to one.

When the safety issue blew up they asked the company about it and they confirmed the "mistakes" are intentional to catch copiers.

I checked the local Ausway map on street-directory.com.au and the phone booth that's on there is actually there, so based on a massive set of two data points and some intuitising in applying typical rates of intentional mistakes applicable to other data, like streets, it's probably only a few phone booths that are intentional mistakes.

Re: South Pacific Sandy Island 'proven not to exist'

#49

Post by mxfh »

LiamMcCalloway wrote: post #46
andyjohnson0 wrote: post #45

Earlier quoted context omitted.

Service Hydrographique et Océanographique de la Marine http://www.shom.fr/

Sorry, I should have been clearer. What did you think the fact that their maps did not show this island mean?

That the only mapmaking authority to whom this island would actually matter is France (SHOM). Since it's in their territorial water and it also would extend their territorial water by being an actual Island. So it's in the very interest of France to have a clear idea what belongs to them and what not, also it's their responsibility to provide as accurate as feasible navigational charts to ensure the safety of ships which travel through their waters.

Look at the french charts featured at geogarage, the post has added a few more SHOM charts for reference which show no Island.

http://blog.geogarage.com/2012/11/south-pacific-sandy-island...

So what does it mean?

Basically one would only need to blame Australia for the lack of funding or interest to ground-truth and update their issued charts outside of their territorial waters. The easiest explanation would be a lack of communication between Australian and French nautical mapping authorities. Second to that the Australian authorities didn't feel the need to do their own mapping by means of actively acquiring of information on the area by satellite, plane or ship for civil applications.

Post reply on HN