How to “clear” the coordinate system of the “Map” to get it to “unknown” in ArcGIS Pro,

[JamalNUMAN]

How to “clear” the coordinate system of the “Map” to get it to “unknown” in ArcGIS Pro,

For example, in ArcMap, the clear option is available and one can set the “data frame” to unknown. I couldn’t figure out how to “clear” the coordinate system of the “Map” to get it to “unknown” in ArcGIS Pro as this option is not there

[XanderBakker]

I suppose there is a reason for that. You are not supposed to set the coordinate system to Unknown. I really would like to know why you would want this...

Below a method to accomplish this, but I urge you not to since it is not a good practice to work with the Unknown coordinate system:

• Add a layer with Unknown coordinate system to ArcGIS Pro
• As shown below, expand the coordinate systems of the Layers and you can add the Unknown coordinate system to your favorites. Now it will always be available to select.

[JamalNUMAN]

It appears that Pro fails to take the “unknown” coordinate system. As it is selected, it gets back to the previous coordinate system (as shown in the screenshots below).

What could be the issue here?

[XanderBakker]

I assigned Unknown when I had no information (even no base map) in my map. Probably the reason that you cannot set it is due to the information that you have in your map. Another indication that you shouldn't be doing this.

[AlvaOlsson]

Hi
I'm facing the same problem but cannot add unknown to favorites or do anything. Is there a workaround or something I'm missing?

[JosephChampagne]

'Unknown' is only selectable under map coordinate systems. Once you're working in a map with 'unknown' projection, you can select the map's projection in other dialogues to inherit the 'unknown' projection.

[DanPatterson_Retired]

There are lots of reasons not to perpetuate 'unknown' coordinate systems

• http://pro.arcgis.com/en/pro-app/help/sharing/analyzer-error-messages/00047-layer-s-dataset-is-using...
• http://pro.arcgis.com/en/pro-app/help/sharing/analyzer-error-messages/00154-layer-s-map-is-using-an-...
• http://pro.arcgis.com/en/pro-app/tool-reference/tool-errors-and-warnings/030001-040000/tool-errors-a...

I could provide more, but there is no good reason to provide an unknown coordinate system when working with spatial data, just lots of bad ones.  If the coordinates are using a 'relative coordinate system' you can still tie them into know data.

[JamalNUMAN]

It appears that our life gets hard without “clear” option. Clearing the coordinate system of data frame or layers helps us understand the data we receive. It is very common in our environment to receive data with unknown coordinate system, then the fist step is to investigate the data and then to assign the proper coordinate system.

For example, clearing the coordinate system of the data frame brings the layer to their absolute location and thus we understand how they are different from one another.

[DanPatterson_Retired]

As long as you put a layer into an empty map (dataframe) you will know what it is or isn't

The first layer added sets it, unless it is set before hand.

The problem arises when people add other data first.

The simplest solution is to explore the properties before hand using python and arcpy in a script devised to examine data before it is even used or brought into arcmap or pro.

[JamalNUMAN]

This appears not to be fixed even in 2.3. “clear” tool is not there!

Why do I need it?

In the screenshot below, I have two layers, on in ITM coordinates and the second is in Palestine 1923 Grid. Now, how can I clear the coordinate of the map (data frame), so that I can see these two layers in their absolute values (as it is used to be performed in ArcMap since ages!)

I would love if this tool gets back!