New XY layer from Lat Long (DD) not plotting correctly

[AlanMcCarthy]

Hi,

I'm trying to create a new point layer from some Lat and Long coordinates that I have in a table (exp. 44.809662,-73.087322
). I used "Make New XY Event Layer" to plot the points. I have some town parcel layers and the point locations are all from within the parcels so the new point layer should be overlapping the parcels. However, they aren't even close!! I thought it might have been my Lat Long Coordinates so I took Lat Long coordinates from five random locations in the area using Google Maps, imported them into ArcMap as an Excel file and tried again. They all showed up really far away also! Their spatial spread looks correct but they aren't close to the parcel layers.

The projection system and the coordinate systems are the same so I'm not sure what's wrong. Any ideas?

Thanks,
Alan

[OliviaDeSimone]

Here is some additional info.

I am trying to match my lat/long coordinates to a street centerline shapefile with GCS_NorthAmerican_1983 as its geographic coordinate system and NAD_1983_StatePlane_Pennsylvania_South_FIPS_3702_Feet as its project.  The extent of this shapefile is as follows:

Top: 433375.665652 ft
Bottom: 382085.723941 ft
Right: 1379567.124976 ft
Left: 1316692.322576 ft

My lat/long coordinates which have the same geographic coordinate system and projected coordinate system has the following extent:

Top: 40.613278 ft
Bottom: 40.518961 ft
Right: -79.971118 ft
Left: -80.141168 ft

Though, now that I type this all out, I see that ArcMap has taken my coordinates and simply converted them into feet.  I can't say I understand why this has occurred.

[MelitaKennedy]

Hi Olivia,

When you use the Add XY Data tool in ArcMap, it defaults the data's coordinate system to the same as the data frame's. In this case, as you noticed, the Excel data is in decimal degrees. Import it again, but change the coordinate system in the tool to NAD 1983 (geographic coordinate system) instead.

Melita

[OliviaDeSimone]

Hi Melita,

I just tried again, and when I opened arcMap, I set the data frame to NAD 1983 which is what the lat/long was collected into.  It plotted the points in decimal degrees, but it still doesn't align with my city data.

[OliviaDeSimone]

Up until now, I have only been working with 4 lat/long points of my total data set.  I just tried plotting all of the data points and the picture that I am adding the this post is what happened.  I also added some city data which you can see as the lines shapefile.

[ATTACH=CONFIG]31048[/ATTACH]

[OliviaDeSimone]

Hi again Melita,

I want to thank you for your help.  I was just not being thorough enough with my data, and after fixing that, your advice on setting the data frame worked. 

I do have my additional question: My data has several additional fields besides just lat and long, and I was encountering an issue where when I added the .cvs file into ArcMap, the field were becoming jumbled.  Ie address was under zip code, my Y field disappeared entirely, and the name of the business was located under address.  Do you know what might be causing this?  I eventually just took the lat/long data and made it its own excel spreadsheet.  I am going to set about fixing it now, and I was just planning to import the additional data in a dbf to attach to my newly created point shapefile of the lat/long.  I'm hoping this works, but I would like to know how to handle this problem should it arise for me again.

Thank you!