problem when convert a x and y file to a point shapefile

[PengGao3]

I was trying to convert a group of x and y coordinates into a point shapefile. I use ArcMap 10.2, Here is what I did:

(1) put x and y (in numerical values) in columns in Excel and convert it into a .cvs file;

(2) in ArcMap 10.2, go to file> add data>add XY data;

(3) for coordinate system, I imported the projection of my reference shapefile;

(4) click ok.

(5) export the layer into a shapefile by right click it and go to data>export data;

After I got the shapefile, I realized that it cannot be in line my reference map though both have the same projection. When I check the converted shapefile, I noticed that its EXTENT is different from that of the reference map.

Could anyone tell me what I did wrong and how to fix this problem?

Many thanks.

Peng

[PengGao3]

?Dan and Rebecca,

It worked !!! Based on what you commented before, I suddenly realized one thing:

the original values of the points are simply lat/long values. When I convert these values into points, no matter what 'correct' projection I will use, it will simply a 'suit' as one of you mentioned on the dog (the lat/long values). This is why the extent of my 'projected' point data shapefile is always based on original lat/long values. The other thing I tried before I posted my question was that when I do the conversion, I did not add any projection. Then, after I convert it into a point shapefile, I define it using the projection of the reference map. It did not work because I noticed that even if I did not add any projection, the extent of the point shapefile is still based on Lat/lomg values. Your comments make me realized one important thing: because the original values are lat/long values, when I convert it into a point shapefile, I should use GCS with appropriate datum! Based on the datum of the reference map, I learned that the correct datum should be NAD 83. So, when I convert the lat\long values into a point shapefile, I used GCS with the datum of NAD 83. After that, I use projection to convert the GCS coordinate system to the one associated with the projection of my reference map. This time, it worked!!!

Many thanks for your help. I hope my summary may help others who have run into the same problem as I.

Thank you again. You made my day!!

Peng

[DanPatterson_Retired]

you are welcome...and I am sure Rebecca feels the same

[SepheFox]

Who???

[PengGao3]

Sorry if I mass up your name. I mean you! Thanks again for your help.

Peng

[SepheFox]

It's ok I'm glad we could solve your problem!

[DanPatterson_Retired]

​Seph...you aren't supposed to mark your own comments as helpful...goes against protocol​ ... could be a glitch but it is showning in the Moderator's view...you should check

[SepheFox]

Ok, my bad. I thought it would help other people find the answer to the same question. Thanks for letting me know!

[SepheFox]

If your point x/y values are in lat/long, then you will need to pick geographic coordinates and then choose the correct datum. Here in North America we use usually use NAD 27 or NAD 83, but I'm not sure where you are.

[SepheFox]

I'm sorry, your screen shot didn't work! If your coordinates are lat/long, then they should be in degree. You would have to REproject to change it to match your other shapefile. Do you see? The program needs to know what the original x/y coordinates are. Once you have made a correctly spatially-referenced shapefile of points, you can use the Project tool to change it.