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I am conducting a habitat suitability analysis using ArcGIS desktop 10.2.2.

I have a vector .shp of a number of georeferenced hare sightings across Ireland, however when I load the layer on to my map, the map will only show my existing layers (island of ireland, approx 1:2,000,000 WGS 1984), or alternatively I can 'zoom to layer' on my new vector, which causes the other layers to disappear but the new polygons to correctly draw, at a scale of something absurdly high, around 1:500,000,000,000.

I have tampered with the 'scale' function to rescale the polygons, but it only seems to make the scale get even larger.

I have toyed with various projections too, but to no avail.

Anyone have any ideas how to reconcile these two?

enter image description here

PolyGeo
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Maggie
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    Seems like you may have them in a different coordinate reference system or projection than your original data. If you can provide the info for both data sets we may be able to help troubleshoot further (what datum, projection, etc found by looking at layer properties). https://support.esri.com/en/technical-article/000006790 – GISHuman Jul 08 '18 at 17:44
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    Based on the coordinates reported by the status bar, it looks like that layer could be in British National Grid (EPSG:27700). Try redefining it with the Define Projection Tool or the layer's property page in ArcCatalog. – mkennedy Jul 08 '18 at 20:35
  • I think this may be a duplicate of https://gis.stackexchange.com/questions/20572/layers-with-same-coordinate-system-should-align-overlap-in-arcmap-but-do-not – PolyGeo Jul 08 '18 at 23:05
  • Need more detail, you say "island of Ireland", what do you mean by that? An island off the coast of Ireland and are you talking about RoI or NI? Now @mkennedy (who one should always listen too) has had a best guess from your screen shot suggesting your coordinate system is meant to be in British National Grid. I typed those coordinates in that we can see and that places it in Anglesey, North Wales, so not Ireland! So where has this dataset helpfully called "Export" come from? Show us the coordinate system it is using (properties of the layer) and where you actually want to display this. – Hornbydd Jul 09 '18 at 12:12
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    My fault; I missed the Ireland comment. Try either 29902 (TM65 grid) or 29903 (TM75 grid). That puts the data in/near NI. Set a transformation too! – mkennedy Jul 09 '18 at 16:21
  • The file has no projection to begin with, I tried assigning WGS1984 (the same as the data frame/other various all island layers i am using but the same issue remained.

    I will try to redefine to the projections suggested by @mkennedy. A further question arises from that however (and please excuse my total lack of understanding of GCS/PCS/projections), but should I only redefine my problem layer to TM65/75, while the data frame/other layers remain in WGS1984? Or do I need to completely reproject the whole project into TM65/75?

    PS alot of v helpful advice for my first ever post, cheers all

     – Maggie Jul 09 '18 at 18:19
  • To clarify - by island of Ireland I am referring to the whole mainland island, ROI and NI. – Maggie Jul 09 '18 at 18:21
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    @Chris Just this problematic layer. But in ArcMap, open the data frame properties, select coordinate system tab and click the Transformations button. Select TM65 or TM75 (whichever one you use) in the top box, and set the first transformation in the pull-down list. – mkennedy Jul 09 '18 at 19:05
  • OK I defined projection, to TM65 for the problem layer only (did so in arccatalog before opening arcmap). Next I opened my project and dropped the newly projected layer in. I then set the transformations as per your instruction.

    The layer is now behaving differently than before, but still not working. Now it doesn't draw at all, and 'zoom to layer' doesnt appear to do anything (scale remains unchanged regardless of where I am zoomed to on map).Thoughts?.. let me know if any extra info needed I can post asap. Thanks again!

     – Maggie Jul 10 '18 at 11:33
  • While no answers have been offered please keep using the [edit] button beneath your question to revise it with the latest state of the single question that you wish to ask. – PolyGeo Oct 08 '18 at 09:47

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