Geoportal better than Google Maps!

[Christophe]

I just re-discovered by chance the famous Geoportail: http://www.geoportail.fr

Frankly, it has evolved very well since its highly publicized release in mid 2006! (and a little fiasco because the tool was not finished, so really premature exit)

The big advantage is the quality of the accessible layers, before either paying or reserved for pros.

For example: built areas, cadastral maps, land use, administrative boundaries, power lines, coastal maps, IGN maps, 3D version, cassini map (historical) ... and lots of other things!

Example of layers:

a) Klaus damage in the South West:
http://www.geoportail.fr/?c=-1.0,44.29& ... 00%29&z=12

b) Biodiversity:
http://www.geoportail.fr/?c=4.25,44.4&l ... 00%29&z=14

c) Power lines:
http://www.geoportail.fr/?c=2.433,49.03 ... 100%29&z=7

Here is what I found in 15 min ...


Really good!

I do not understand that such a tool, so powerful and completely free, is not better known ... We talked about it so much in 2006 when it was badly finished and today, nothing in the media ... pfff there are things that will always elude me!

[chatelot16]

but if there is an effective media which speaks about it: econology!

[Forhorse]

For my part I know pretty well, I use it quite often.
There is also a new function that I like: the possibility of having a layer with the previous version of a satellite photo, it allows you to see the evolution of certain areas (extension of wasteland, new construction, etc ...)

In the same genre, for the cadastre, there are also:
http://www.cadastre.gouv.fr/
Which, as its name suggests, contains extracts from the cadastre up to date and officially in force (unlike geoportail where it is not always up to date)
and a lot of handy little tools (handling is not obvious but it is ultimately simple) like distance, surface, angle ...
Very practical for building permit applications (for example)

[sherkanner]

In addition the maps and aerial views are more up to date than on google

[Christophe]

It's too much honor chatelot16

There is also a new function that I like: the possibility of having a layer with the previous version of a satellite photo, it allows you to see the evolution of certain areas (extension of wasteland, new construction, etc ...)

I did find the "aerial photo 2000-2005" layer, but is it further? I mean N historical version to see the more distant evolution?

ps: I'm not talking about Cassini eh . Cassini is good, I think, to see how the importance of places has varied in history! Some small villages are indicated in very large ... certainly an indication of their importance at the time?

[Forhorse]

For now no, there is only the 2000-2005 layer, ie the previous version of the data. Before I think the sattelite photos were not "public" or simply nonexistent * (and certainly the old aerial photos are too precise * or "secret defense" to be published like that)
We will have to wait for the next update (2015?) To see if we will have 2 layers or that they will always leave only the N-1 version.

* Do not forget that before the 2000s the photos were silver and that the observation sattelite probably had no way of taking photos (I think they worked in infrared)
Suddenly digitize the aerial photos taken before this time represents much too important work for the little interest that it presents. this should only be done on a case-by-case basis according to the needs of the administration.

[Christophe]

Ah thank you for these details.

But uh ... geoportail is satellite or aerial photos? (or a mix of the 2?)

Because the layer is called "aerial photos" and not "satellite photos" so I have a doubt there ...



Otherwise, not installed the plugin yet: the 3D version is worth it?

[elephant]

Forhouse said:

Do not forget that before the 2000s the photos were silver and that the observation sattelite probably had no way of taking photos (I think they worked in infrared)
Suddenly digitize the aerial photos taken before this time represents much too important work for the little interest that it presents. this should only be done on a case-by-case basis according to the needs of the administration.

???? to my knowledge, "we" have been transmitting digitally to the ground for a very long time, even when NASA once declared that it was no longer able to read the old tapes from the sixties (at the time when we read huge tapes in 60 m high drives.

[Forhorse]

???? to my knowledge, "we" have been transmitting digitally to the ground for a very long time, even when NASA once declared that it was no longer able to read the old tapes from the sixties (at the time when we read huge tapes in 60 m high drives.

Yes for the transmission, but for the photo sensor?
At the beginning of 2000 when a digital consumer camera displayed 1 million pixels it was top of the range.
We can assume that the military and space applications had this resolution a few years before us (and that it cost the eyes of the head) but did they make the decision at the time to integrate it into a satelite?
http://fr.wikipedia.org/wiki/Satellite_Spot

[Christophe]

Uh, don't exaggerate ...

US military satellites probably had 10 Mpixels in the early 90s ... right?

But I am not sure that it is the resolution of the sensor that counts on a satellite but rather the quality of the optics (a 10 Mpixels photo is how many 0.1 Mpixels photos? In other words: just make several passes ...)

To check ... I know quedale ...