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

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

JamalNUMAN — Sat, 18 Nov 2017 20:11:20 GMT

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

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

XanderBakker — Sat, 18 Nov 2017 21:20:06 GMT

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.

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

JamalNUMAN — Sun, 19 Nov 2017 18:10:46 GMT

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?

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

XanderBakker — Sun, 19 Nov 2017 18:28:06 GMT

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.

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

DanPatterson_Retired — Sun, 19 Nov 2017 18:41:16 GMT

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

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.

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

JamalNUMAN — Fri, 01 Dec 2017 11:46:45 GMT

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.

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

DanPatterson_Retired — Fri, 01 Dec 2017 11:52:43 GMT

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.

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

JamalNUMAN — Fri, 15 Mar 2019 11:48:54 GMT

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!

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

GregoryLund2 — Mon, 14 Oct 2019 02:13:56 GMT

Jamal, thank you for starting this discussion.

Dan, I appreciate your comments on this post, as i have the same questions as Jamal. I use the 'clear projection' as a stop gap measure to prevent 'projecting on the fly' in ArcMap, almost identically to how Jamal uses it.

My concern is how ArcPro knows which projection to use for the layer. If the projection (or coordinate system) is defined incorrectly, how would ArcPro know? Where would it 'put' the data in space?

It sounds as though it would project on the fly, to the incorrect coordinate system?

Agreed that determining the actual coordinate system ahead of using the data is the best approach. I do so, and direct my students to do so, however, this 'clearing of the projection on the fly' is a good stop gap measure to ensure that the data is lining up.

Thoughts?

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

DanPatterson_Retired — Mon, 14 Oct 2019 03:17:22 GMT

Gregory... When I am using someone else's data, I actually follow the advice given in the previous threads.

I don't like to rely on stop gaps or anything else.

In fact, I still think projection on the fly was a bad idea when it was introduced.

At least in old-school arcview 2/3.x, when you data "didn't line-up" you knew that you were dealing with unknown or incorrectly defined coordinate systems.

People waste more time trying to figure out why subsequent processes don't work properly than they would by getting the data into the necessary and the same coordinate system to begin with. Storage is cheap. I keep my data in geographic and projected coordinates and I use the form appropriate for the task

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

GregoryLund2 — Mon, 14 Oct 2019 03:22:58 GMT

Dan,

I'm in full agreement on checking and double checking, but... when teaching students, i have found that this little 'stop gap' is a great way to show it to them, explain about the data being in different spaces.

If they click 'full extent' and their data doesn't line up, they know that they forgot to do something.

Similar with 'Clear Projection'... If one of the layers disappears.... they realize right away that there is an issue.

This gives them a visual, and concrete reasoning of why we must line up our data, rather than it being an abstract concept. Thus far... 10 years in, it has worked, students 'get it' and rarely make Coordinate System/Projection mistakes after the 'Coordinate System and Projections' lab!

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

DanPatterson_Retired — Mon, 14 Oct 2019 04:00:18 GMT

True Gregory... as long as they remember to zoom to full extent

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

JamalNUMAN — Tue, 15 Oct 2019 19:34:12 GMT

I’m sure, Dan, why are even against to having it an optional!. We do really need it at our work and can’t live without it.

I would appreciate if other experts can share us the discussion on this

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

GregoryLund2 — Tue, 15 Oct 2019 19:52:51 GMT

I'm writing to ask... what does ArcPro do then? Project on the fly? Project in the Layer's coordinate system? I haven't been able to find the answer to this.

Ironic... I just uploaded a video about Coordinate Systems and Projections for my introduction to GIS course at the University of Washington Tacoma.

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

Robert_LeClair — Tue, 15 Oct 2019 20:13:32 GMT

So in researching this question a bit further, there is a bug number (BUG-000114029) for it although technically it's not a bug. As described to the customer "Unfortunately removing the ability to set 'none' coordinate system in Pro is a design decision. Having no coordinate system could lead to lots of problems..." The support call also references this thread as well. Lastly there is an ArcGIS Idea submitted for this item that is marked as Reviewed.

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

deleted-user-2Fg69EwaShGZ — Tue, 15 Oct 2019 20:22:03 GMT

Having an "arbitrary plane" or no projection is used when bringing in data from many data sources. It is important to have this functionality in the software to make it as flexible as possible for many different types of users and uses. Many spatial data outputs from other software don't always work directly with ESRI products, especially in Raster workflows, so being able to see the actually pixel coordinate in the image structure is useful and necessary.

And the real thing that annoys many many arcGIS users is: Why does ArcPro eliminate functionality that has existed in past software, but ESRI doesn't think is useful or shouldn't be there for unknown reasons? ESRI you should listen to your userbase a lot more. Many have been posting on forums like this for years about reasons why they need fuctionality, but it feels like you aren't listening or dont care.

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

Robert_LeClair — Tue, 15 Oct 2019 20:37:55 GMT

Nelson - as a Senior Instructor in Esri Training Services, I have zero pull/sway on the AGP development processes and do my best to answer customer questions on the ArcGIS Platform. Esri employees do read/review/provide input on GeoNet threads and do listen to customers requests for equivalency/additional functionalities in software development. The whys and how's of functionality being (or not being added) are beyond my control. Kory Kramer‌ is the ArcGIS Pro Customer Advocacy point of contact and is cc'ed on my response. Perhaps he can provide additional information.

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

GregoryLund2 — Tue, 15 Oct 2019 20:57:09 GMT

Understood Robert, and thank you for your input. Coincidence, I attended Grad School with Kory!

Question... what DOES ArcPro do? Project on the fly? Put layers in their respective coordinate systems?

I'm guessing 'Project on the fly' is the only 'OPTION'?

🙂

Regards,

Greg

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

Robert_LeClair — Tue, 15 Oct 2019 21:06:38 GMT

Love the fly graphic! That's awesome! Small world too about you and Kory - very nice!

So yes, AGP does "project on the fly" as does ArcMap. From the ArcGIS Pro help -

"ArcGIS Pro reprojects data on the fly so any data you add to a map adopts the coordinate system definition of the first layer added. As long as the first layer added has its coordinate system correctly defined, all other data that has correct coordinate system information reprojects on the fly to the coordinate system of the map. This approach facilitates exploring and mapping data, but it should not be used for analysis or editing, because it can lead to inaccuracies from misaligned data between different layers. Data is also slower to draw when it is projected on the fly. If you intend to perform analysis or edit the data, then first project it into a consistent coordinate system and the same coordinate system shared by all your layers. This creates a new version of your data."

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

DanPatterson_Retired — Tue, 15 Oct 2019 21:14:43 GMT

What would be nice.... a banner on the top of the map/data frame which states.

….. CAUTION.... one or more layers is being projected-on-the fly.... CAUTION ….