How to clear\define the coordinate system of a particular layer in catalog of ArcPro?

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08-19-2019 11:49 AM
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JamalNUMAN
Esteemed Contributor

How to clear\define the coordinate system of a particular layer in catalog of ArcPro?

 

This option appears to be not available in arcpro

 

This idea is already discussed here

How to define the coordinate system of a layer while working in catalog of ArcGIS Pro,

 

 

 

rawan saleh‌, Majdoleen Awadallah

8 Comments
KoryKramer

Referencing the discussion that has already been had on this subject here: How to “clear” the coordinate system of the “Map” to get it to “unknown” in ArcGIS Pro, 

There was an issue submitted by Technical Support for this and it currently has a status of Not In Current Product Plan with this explanation, "Thanks for submitting this issue. Unfortunately removing the ability to set “none” coordinate system in Pro is a design decision. Having no coordinate system could lead to lots to problems. For example, units will be unknown and map scale is off as well. It’s dangerous to have a map in an unknown state without coordinate system. Features will not draw correctly and sharing map across in platforms will also have problems. Therefore, it’s unlikely that adding <none> option in the coordinate system in map properties page."

Jamal NUMAN‌ you've already provided an explanation on the thread referenced above, for how you use this.  For others voting up this idea, please also include how you currently use this functionality.  Is it solely for troubleshooting and correcting projection issues?

JamalNUMAN

Precisely. We do use it for troubleshooting. The absence of this tool (clear) makes it difficult to display how layers are plotted with their native coordinate system.

 

This tool has been existing since ever in ArcMap. We never encountered in issues that is associated with the availability of it.

GregoryLund2

Jamal, I agree 100%. Jamal NUMAN

Kory, I have attempted to explain here further. Kory Kramer

I utilize the 'Clear Projection' as a stop gap measure to ensure that my students see (visually) that their data does not 'line up', and something must be done.

Even with the minutia of differences between very similar coordinate systems, showing, visually that the layers are 'off' helps students understand this seemingly abstract issue of 'Spatial Reference'. Imagine looking at two identical layers of Tacoma, one in UTM Zone 10N, one in WA State Plane HARN South US Feet, one in WA State Plane South US Feet, and another in WA State Plane South Meters. In ArcMap, they seem to line up while...Image of a fly, with a globe on it. (Projected on the fly), City of Tacoma projected on the fly, all 4 layers (different coordinate systems but after clearing the projection... Image of "Clear Projection" in ArcMap 10.7.1 of course... Image of "No coordinate System" only 2 of the Layers 'Line up' (notice the quotes)Image of 4 Layers in different Projections. but... wait... Image of Tacoma, area of Ruston circled. Under further investigation... our eyes are deceiving us..... Image of the 1 foot difference between State Plane HARN and State Plane. . There is a 1 foot (ish) difference between State Plane and State Plane HARN. 
The good news is, I can create a video of this, to show students long after ArcMap is a distant memory. While completing this reply, I've realized that this is such a VALUABLE teaching tool, to show new GIS students (TGIS 311, Intro to Maps and GIS" the 'abstract' nature of these confusing things called 'Coordinate Systems, Projections, Transformations, Datums, Ellipsoids etc.

With the Projection of the Data Frame left at 'No Coordinate System', I am sure that ArcMap is using the actual coordinate system of the layers. ESPECIALLY when a layer 'says' it has one coordinate system, when in fact it has been Defined and/or Projected incorrectly.

Try explaining to a new student (Week 4 of Intro to GIS) that "Yes, ArcMap does show that those two layers have the same coordinate system and projection... but... they do not". Being able to SHOW them that, in ArcMap, is a teaching/learning opportunity.

I've taught this way for 9 years, and not one analysis has been destroyed because there was 'No Coordinate System'.

Question... (Kory, or other Esri folks), what if a Layer, with an incorrectly labeled Projection/Coordinate System was added to ArcPro? Would it be projected on the fly to the actual corrupted coordinate system (never never land), or to the incorrectly specified (by name) coordinate system?

btw, this is all RESPECTFULLY submitted, not trying to be a jerk, PNW passive aggressive, etc. 🙂 I'm attempting to explain how I use this feature of ArcMap as a tool for accuracy in my analyses and a teaching tool. I'm trying to learn, and figure out the best way to educate my Undergraduates at the University of Washington Tacoma in the School of Urban Studies (and also making a case for 'bringing the 'clear projection' back. Can it hurt?) 🙂

(Also hoping to hear what exactly ArcPro does... )

Does ArcPro Project on the Fly to the first layer added? I honestly don't know, and am hoping to hear. Also, can it be changed (I haven't used Pro much) as desired? Will ArcPro project to the Actual Coordinate System, a corrupted coordinate system (incorrect due to using incorrect Datum/Defined Projection), or the named (but perhaps inaccurate Defined Projection?

Regards,

Greg

ThomasColson

This option is used in ArcMap when we get data that started off as a CAD dataset, and someone (else) "guessed" at what the projection was, and they were clearly wrong, but we have no idea what the CAD was originally "rotated" to. "Having no coordinate system could lead to lots to problems.". There is no disputing that. And I haven't seen any use cases for folks wanting blindly use unprojected data and make bad maps. There are specific technical troubleshooting situations where the functionality is needed. 

(Also appears to be a duplicate of  )

RandyMcGregor1

I create cross sections that are feature classes - with routing, events, dynamic segmentatoin etc. in Arcmap I put them in a map frame with no coordinate system defined - just a blank, cartesian space. Would be nice if we could decide for ourselves whether or not to enter a defined coordinate system.

In fact, "Cartesian Grid" would be a wonderful coordinate system option.

GeorgieCassar1

I have cases where data is provided to me that displays in the wrong place. The provider seems to assign a coord system that is obviously wrong.  I like to troubleshoot by clearing the assigned projection and assigning different  projections I think it could be. This trial and error helps to correct the problem. It's like doing a 'project' without moving the features. 

JamalNUMAN

At the end of the day, we do really need to get this option (clear) available to Pro. In many cases, the absence of this option makes our life hard.

SusanGale1

I have always cleared the projection in ArcMap while doing visual quality reviews of results from raster analyses. I generally create a random raster that matches the extent of the state I work in to use as a common reference for snapping and extent to ensure that my statewide projects as well as smaller project areas will all align to a common source and therefore be reproducible. Unfortunately, I made an error when creating the most recent reference raster and it looks like it took the projection of the input vector data I used, rather than the projection I selected for my project. I've been having a lot of crashing and unexpected results in my current project, but results seemed to be just fine in my visual reviews (rasters from results were all in the correct projection). I just discovered the error today, and this is the exact type of error I would have caught previously by clearing the projection from the map during my visual reviews -- i.e., misalignments between my reference raster and the rasters from my analyses. And now I have about 6 weeks worth of work to re-run. (Thankfully, almost all of my work is scripted, but will still take some time to re-run the spatial data and then re-analyze the results.) In my case, not being able to clear the projection in the map has actually masked serious issues with my underlying data and actually harmed my data quality, not helped it.