#DrSpotfire - Polar Projections

[Elena Nedelcu]

How easy it is to re-project Spotfire maps into other projections, namely polar ones.

I found this explanation in the manual If you want to use Map Layers in your map chart, the Coordinate Reference System on the Appearance page must be set to EPSG:3857-WGS 84 / Pseudo-Mercator.

What happens in case you have map layers in Polar projections Do you have to set a certain coordinate reference system for the Map appearance and a different one for the data layer

# Is it possible to have the option to enable an end user to change the projection For example to switch from an European projection to a polar Projection (Web Player end user).

Thank you.

[Arnaud Varin]

You can use the CRS of your choice foryour data layers however the map background (Map Layer) only supports EPSG:3857-WGS 84 / Pseudo-Mercator.

We support more than 3000 CRS and you can see the full list of supported CRS by doing this:

1. Right-click on your layer > Layer Settings

2. Under the Data panel and under Coordinate reference system, click Other...

[Arnaud Varin]

Hello Elena,Apologies I didn't see question relates to Web player.

It is currently not possible to change layer CRS from Spotfire web player; only from the Analyst (desktop) client for now. We may change this in the future.

[Elena Nedelcu]

Hi Arnaud,I have used the existing Polar Projections but it doesn't seems to work. The fact that only supports Pseudo-Mercator its a problem for us, as we are working with global datasets in diferent projections.

Is it possible to add / enable a Google Earth style 3D globe projection This will solve many issues we noted with World Mercator, lack of Polar projections, etc.Thanks,Elena

[Neil Kanungo 2]

Hello Elena,

 

Probably too late for you but just saw this and responding here anyways for other users.

 

I think there's some confusion in the responses.

 

You can change the map background to be different projections by using WMS and TMS layers. (I believe ArcGIS will allow you to create a custom projection and WMS layer which you can then access from Spotfire; alternatively you could find an existing one that suits your needs). Here's how you change WMS and TMS:https://community.spotfire.com/wiki/geoanalytics-resources

 

Next, your data layers need to be projected appropriately. You can change the CRS for these as Arnaud mentions in the Map Properties;the same data points can be projected to different CRS in different layers (only one CRS per layer though). There are thousands of pre-defined projections and you can also enter customprojections as a PROJ4 string. You could project your polar coordinates Spotfire's default Mercator and use the default background, you could also leave in polar coordinates and use a custom WMS/TMS map background, or you can project into some other CRS useful for you.

 

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(You can stop here if you'd like. If you want your web player users to be able to switch between different CRS views, keep reading)

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The Spotfire Web Player does not allow users to change CRS in browser natively, however, simple IronPython scripting can be used to create a button/link that they can select to toggle different CRS modes.

 

You could have, for example, 4 layers:

 

Background Base Layer - Polar

Data Layer - Polar

Background Base Layer - Mercator

Data Layer - Mercator

 

By using this IronPython script to toggle multiple layers on/off, you could have one setting where only layers 1&2 show and another setting where only layers 3&4 show. This would switch the view from polar to mercator view for both map background and data layer. Here is the script for implementing such a shortcut:https://community.spotfire.com/wiki/ironpython-script-toggle-map-layer-visibility

 

We also have a video being released on YouTube this Wednesday that will show how to toggle layers like this.

[Jose Catala]

Hi,

I have loaded a TMS (Tile Map Service) of the north pole region (from Artic Web Map Tiles) into Spotfire. It is a map in Coordinate Reference System EPSG:3573.

The map is properly displayed in Spotfire, but only if Map Chart Properties / Appearance / Coordiante reference System is set to EPSG:3857 (WGS84 Pseudo Mercator). If I set the CRS to be EPSG:3573 (North Pole LAEA Canada), then the Map is not displayed and the message " 'TMS Layer' can only be shown in the coordinate reference system 'EPSG:3857' " is displayed.

I tried to leave the Map (TMS) in EPSG:3857, which is the only option allowing it to be displayed and then to set EPSG:3573 for the marker layer (from a table with latitude and longitude values), but the marker layer is not properly displayed. 

Any clues on how to proceed in order to plot a marker layer into a Map which is not in EPSG:3857 coordinates (cylindrical projection)? How should we proceed in order to enter a map in another type of reference system (e.g. via TMS) and then to display the marker layer properly??