Display XY Data

[RobRees]

Hi,

I expect this question has been asked several times previously and I have looked through some discussions on this topic and also followed some tutorials.

However, I'm having difficulty importing a table of coordinates into arcmap.

The mxd I currently use has several layers and points are spatially positioned from linear referencing. A route name and a distance along that route.

I now have a table with a set of coordinates for places of interest within the UK.

The current properties of the existing data frame of my mxd are...

British_National_Grid

Projection: Transverse_Mercator

False_Easting: 400000.000000

False_Northing: -100000.000000

Central_Meridian: -2.000000

Scale_Factor: 0.999601

Latitude_Of_Origin: 49.000000

Linear Unit: Meter

GCS_OSGB_1936

Datum: D_OSGB_1936

I believe the coordinates of the points I am trying to import are WGS1984. As this is what modern coordinates generally are?

These are the steps I have taken so far...

I have added the excel table containing the point data into the mxd.

Right clicked this in the layer window and chosen 'Display XY data'

Then set columm X Y to the appropriate columns in the table

If I try to plot this nothing is generated.

What do I have to change the coordinate system to for this table and do I need to change the coordinate system for the mxd itself etc and will this have any effect on other elements in my map?

Thanks,

Ray

[AdrianWelsh · Accepted solution]

Hi Rob,

I have come across this issue a few times where my existing MXD is in my local system and I want to put in XY data that is in WGS 84. Simple enough, I go into the Layers Properties > Coordinate System tab, and change the system to WGS 84. I put in the XY data (Add XY...), and verify it comes in where it should. Then I usually export my XY data to a feature class in order for it to be saved, then change my system back to my local system. I hope that makes sense. It's a few steps but it works.

[RobRees]

Hi Adrian,

Sorry for the delayed reply.

Thanks for your suggestion. That has worked and I have now implemented it to visualise the points of interest.

Rob.

[AdrianWelsh]

Rob,

I am glad to hear it worked. If this answered your question, please mark the response as "correct".  Thanks.

[DanPatterson_Retired]

show a portion of the table

If the coordinates are in degrees minutes sec, then need to be converted to decimal degrees

Once added to an EMPTY data frame, their coordinate system needs to be defined, if from gps, generally a geographic coordinate system WGS84 datum.

export/save to a featureclass or shapefile so it is more than an event theme.

To combine with other data in a different coordinate system, you can physical produce a file in that system using the Project Tool, otherwise you can rely on the whim of on-the-fly projections to get everything lined up.

The best practice is not to mix data in different coordinate systems... use only what you know, and know what you use.

[RobRees]

Hi Dan,

Thanks for the information