topic Re: Points created in excel keep projecting at the equator in Data Management Questions

Points created in excel keep projecting at the equator

EmmaFlanagan — Thu, 28 Jul 2016 15:18:07 GMT

I have created a list of points in excel with X and Y co-ordinates. The co-ordinates are in WGS 1984. When I bring them into ArcGis (I'm using version 10.4.1) they keep projecting at 0,0 (so basically the equator). The points are meant to be in Ireland. I can see by the shape of them they are projecting in roughly the right order. Nothing I do seems to make them project in the right location. Does anyone have any idea how to make them project correctly?

TIA

Re: Points created in excel keep projecting at the equator

BenjaminMittler — Thu, 28 Jul 2016 15:29:27 GMT

When in data view in the bottom there should be x and y values and a unit. What is the unit associated with these values? You could also check the data frame properties for this same unit.

Re: Points created in excel keep projecting at the equator

ChrisDonohue__GISP — Thu, 28 Jul 2016 16:26:40 GMT

Another item to help in troubleshooting - check the Properties of the Data Frame to see what it is using. It may be that the Data Frame is set to an inappropriate coordinate reference system. Keep in mind the Data Frame "inherits" its coordinate reference system from the first layer loaded into ArcMap (and if the first layer loaded in had an Undefined reference system, the Data Frame will be Undefined).

Chris Donohue, GISP

Re: Points created in excel keep projecting at the equator

DarrenWiens2 — Thu, 28 Jul 2016 16:36:14 GMT

It sounds like you've got lat/long coordinates (degrees) that are being assigned a coordinate reference system measured in some other unit (probably meters). Can you show the coordinate reference system you assign in the Display XY dialog box? It should be plain, old, geographic GCS_WGS_1984 (i.e. not projected).

Re: Points created in excel keep projecting at the equator

RebeccaStrauch__GISP — Thu, 28 Jul 2016 16:46:29 GMT

Make sure you don't have the X (longitude) and Y (Latitude) reversed, and the Latitude longitude as negative if in the western hemisphere. Also, deicmal degrees work best.

edit: and if you are reading them in as an event theme, make sure to specify the WGS 84 as the coordinate system in the wizard.

edit2: Melita Kennedy Thanks for the catch....yaaa...I know better....just a typo, but fixed now. I'll blame it on my keyboard having issues today with cut-n-paste.

Re: Points created in excel keep projecting at the equator

MelitaKennedy — Fri, 29 Jul 2016 00:04:51 GMT

<psst> "longitude" in western hemisphere

Re: Points created in excel keep projecting at the equator

AbdullahAnter — Fri, 29 Jul 2016 03:06:13 GMT

When you use Add X & Y Data tool , make sure that you choose the correct spatial reference ( WGS 84 similar to excel sheet coordinate).

Re: Points created in excel keep projecting at the equator

EmmaFlanagan — Fri, 29 Jul 2016 08:07:27 GMT

Thanks for the comments and help.

I can confirm it is projected in WGS84. The Co-ordinates are in decimal degrees, and include a negative latitude. The co-ordinates are all in the region of 53 (longitude) and -8 (latitude) which would be correct for Ireland. In order to make sure its not picking up any issues from a projection system on a different co-ordinate system I've projected them on the OpenStreet Map basemap which as far as I'm aware uses WGS84.

The units of the data view are in meters. I've checked the data frame extent and it appears to be set at 0. Below is a screen shot of the layer properties.

Re: Points created in excel keep projecting at the equator

DanPatterson_Retired — Fri, 29 Jul 2016 08:29:09 GMT

well a sample of the data as suggested would be in order since you appear to be floating in single precision space near the equator where your bounds are nearly equal. I would suggest posting a sample of the data since the extents of your geodatabase are just wrong.

Re: Points created in excel keep projecting at the equator

EmmaFlanagan — Fri, 29 Jul 2016 09:29:00 GMT

Fair enough. Here is a screen shot of my attribute table.

In case its important, I'm using a basic licence.

Re: Points created in excel keep projecting at the equator

DanPatterson_Retired — Fri, 29 Jul 2016 09:57:04 GMT

Ireland you say??? Well according to your longitude and latitude fields, they have been swapped.

The coordinate values in those fields are indeed decimal degrees... just in the wrong order.

I would try to add that table as an event layer into ArcMap... in a brand new project with nothing else in it

Make XY Event Layer—Help | ArcGIS for Desktop

just remember your latitude field is actually longitude and longitude is actually latitude.

add it to a geodatabase or make a shapefile or whatever

The output point feature layer created by this tool is temporary and will not persist after the session ends. You can export this event layer to a feature class on disk using the Copy Features, Feature to Point, or Feature Class to Feature Class tool.

I would define it as a GCS WGS84 (aka geographic coordinate system wgs84 datum... aka decimal degree data ... unprojected data) as a good guess. (see below)

Then and only then, add some other data to see if it appears in Ireland and not near the equator

PS you use the Define Projection tool to tell the file what it is Define Projection—Help | ArcGIS for Desktop a GCS WGS 84

if you want some other coordinate system, then you use the Project—Help | ArcGIS for Desktop