Hacker News new | comments | show | ask | jobs | submit login

It's the same black blob. As usual, there's no higher-resolution data for small remote islands.

Though if it weren't labeled as "Sandy Island", I would think it's just an artifact of some kind. It certainly doesn't look like any real island at that distance.


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 oldmapsonline.org dates back to 1881 While this otherwise well explored map[5] of 1862 does show nothing in place.

GeoGarage[6] pretty much says the same.

This only shows how slowly low priority public datasets are updated/maintained since the french maritime authorities SHOM don't have anything in their official charts of the area.



[3]http://landsatlook.usgs.gov/ sorry no direct link possible, just got to the location zoom in and search for available imagery.




Not sure what you mean about SHOM?

Service Hydrographique et Océanographique de la Marine


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.


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.

Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact