Having trouble mapping XY data in ArcMap

[NicholasSievers]

Hi everyone,

This is my first ever post. I am having trouble mapping latitude and longitude coordinates in ArcMap. I am having trouble plotting XY coordinates in ArcMap 10.7. I imported points from a device called PocketLab. These are normal XY coordinates, but when I turned them into a feature class and tried to overlay them on the Oregon counties, they don't show up. I can confirm that the coordinate system and dataframe match for all my items.

[curtvprice · Accepted solution]

Things should work fine from Excel. Just follow the step by step in the KB article and you should be fine.

You do not need a shapefile to plot points, they are "events" dynamically drawn from the table. You can then right click the event layer, save as shapefile or feature class once you have the points plotting on the map.

This is all detailed in the KB article.

[NicholasSievers]

You both were very helpful, although what ended up happening was that I zoomed way out and discovered that the points were plotted, just on the inverse location of the map. This got me thinking that my latitude and longitude are backwards. Bingo! That was the problem!

[DanPatterson]

While you are at it and if you are doing this in Pro. 

If you have a csv  - https://pro.arcgis.com/en/pro-app/tool-reference/data-management/xy-table-to-point.htm 

or if you have an extremely clean excel file

Excel To Table (Conversion)—ArcGIS Pro | Documentation

and use a file geodatabase rather than a shapefile unless you need a shapefile for some other program.

[Hussam_AlJabri]

Hey NicholasSievers,

You need to change the coordinate system to a geographic coordinate system to present the Lat and Long.

[DanPatterson]

guess you missed that in my post

I suspect that your long-lat points don't have a defined Geographic Coordinate System (perhaps GCS WGS84)

[curtvprice]

This is a shortcoming in the ArcMap interface they fixed in Pro. Unfortunately when you try to add XY the interface by default assumes the coordinate system of your points is the same as the data frame (map). The fix (Step 8 in the KB article) is to change the coordinate system (in the dialog, not the data frame's [map's] coordinate system) to one that matches the XYs in the Table fields. Probably something like GCS WGS84 (a common default for GPS data).

Here is an Esri KB article that walks you through the process with lots of detail:

https://support.esri.com/en/technical-article/000018076

I also like to plug a friend of mine's book: Lining Up Data in ArcGIS. It's awesome.

[RichardDaniels]

Steps are:

0. Open ArcMap, do not load an existing MXD.

1. add a table to ArcMap, this can be an Excel worksheet or .csv file. If using .csv ensure you have a header row.

2. look at your table in ArcMap, what are the x and y fields called? Look at the coordinates, are they longitude and latitude decimal degrees or something else like UTM?

3. Use Map an XY option on the table, use the field names identified in step 2 as input.

4. You will see your points on the map and a New Layer will be added to the map

you now have two options, define the projection for the Layer and Save to a .lyr file

OR

5. right click on the layer and Export Data to Shapefile.

6. Use the Define Projection in ArcToolbox to set the projection.

 Now when  you load the shapefile or layer file into your 'other map' it will be reprojected on the fly to match your Map document.