Decide on projections for each region

[MattF-NSIDC]

https://trello.com/c/1kxdQnAG/166-base-maps-in-selected-projection-for-each-region

We currently have the Western US only and use Web Mercator

Here’s the plan for the other regions:

HMA and westernUS: Web Mercator: EPSG:3857

Alaska: Lambert Conformal Conic: EPSG:3978?

Greenland: Polar Stereo

South America: ESRI: 102015 South America Lamber Conformal Conic or ESRI:102032 South_America_EquidistantConic? [Seb] Temporarily Web Mercator EPSG:3857_

Canada: Lambert Conformal Conic: EPSG:9802

Southern European Alps: I think we can use Web Mercator: EPSG:3857

New Zealand: ?

[sebastien-lenard]

Greenland: NSIDC has apparently varied polar stereo projections, https://nsidc.org/data/user-resources/help-center/guide-nsidcs-polar-stereographic-projection, to investigate and decide when time (not urgent)

[sebastien-lenard]

South America: It might be necessary to split in 2 projections:

Argentina-Chile and the north of South America.

Right now, I propose to do it in web mercator as for US and HMA, and we could change before launch

[sebastien-lenard]

For Alaska, EPSG:3978 would work, but is there any basemap available? I will temporarily also generate the geojson in EPSG:3857 and we'll be able to shift once the basemaps will be found.

[MattF-NSIDC]

I found a post from 2018 referencing this basemap provided by Natural Resources Canada:

https://geoappext.nrcan.gc.ca/arcgis/rest/services/BaseMaps/CBMT3978/MapServer/tile/{z}/{y}/{x}

But the basemaps from that server are returning errors today. I think it might be useful to search specifically for services provided by the Canadian government or NGOs. Perhaps site:*.ca will help find those results?

[windnagelnsidc]

Yes, I was thinking something similar. I'll do some more digging on that.

[sebastien-lenard]

Doesn't the USGS have anything for at least Alaska? (Canada has a lower priority I think)

[windnagelnsidc]

The USGS ones for Alaska seem to be in Web mercator. But I'm still looking.

[windnagelnsidc]

Here are some things I found: https://docs.google.com/document/d/1PUZ54NieWbK9RU-dY0VCkMQUUnQClUKazaPiANa3V0I/edit

[MattF-NSIDC]

Today at standup we decided we will discuss with Karl the idea of using Web Mercator everywhere; finding basemaps in other projections from reliable sources has been challenging. We can always come back to this later if we find more basemap sources.

[windnagelnsidc]

We will use the web mercator (EPSG: 3857) projection for AK and Canada. We do want a polar projection basemap for Greenland, however. See https://github.com/nsidc/snow-today-webapp-server/issues/35.

Matt and Sebastian will continue to develop the back-end so that we can choose any basemaps we want in the future.