coordinate reference system (CRS)

[dahlalex]

What are the CRS:s that are supported by leafmap? Is there a way to convert the CRS?

[giswqs]

For vector, leafmap supports any CRS supported by GeoPandas. Under the hood, all CRS are converted to WGS 84 (lat/lon) to be displayed on the map.

For raster, leafmap supports any CRS supported by ipyleaflet, which only supports a limited number of CRS. See https://github.com/jupyter-widgets/ipyleaflet/blob/stable/ipyleaflet/projections.py

[dahlalex]

Thanks, So in order for data to be displayed correctly on the map, it should be converted first to WGS84 EPSG:4326. Can one change the CRS of the basemap instead?

[rh-afk]

can we use custom projection as mentioned in this link
[https://github.com/jupyter-widgets/ipyleaflet/blob/master/examples/CustomProjections.ipynb]
and use leafmap to display the map?

[giswqs]

Yes. Leafmap supports anything ipyleaflet supports.

[rh-afk]

Thanks @giswqs for your information, unfortunately I just reproduce example from above link with my local server tile layer , in ipyleaflet it displayed tilelayer but when use the leafmap, it shows nothing. Is there any consideration that I must aware about that in leafmap.

Thanks

[giswqs]

Works fine on my end.

import leafmap
from ipyleaflet import (
    basemaps,
    projections,
)

m = leafmap.Map(
    center=(90, 0),
    zoom=0,
    basemap=basemaps.NASAGIBS.BlueMarble3413,
    crs=projections.EPSG3413.NASAGIBS,
)
m

[rh-afk]

Thanks @giswqs , if I want to use arc gis tile server is it the same code too? and how about plot some data point from dataframe or add additional layer to that map?
kindly please advise.

thanks