topic Re: lat and long in Mapping Questions

lat and long

francescarusso — Thu, 08 Jun 2017 15:16:45 GMT

Hi all,

I reckon I have lots of gaps about carthography but normally I do not struggle too much in converting coordinates.

I have to plot some coordinates in ARCGIS.

They are in the format below:

43°31.4, 1°46.4

First of all if I tried to add a point (using Go to XY tool) into GIS just to see where these coordinates are it show them in the wrong place.

Normally when I want to convert coordinates in easting and northing to be able to plot them in GIS I do:

(min/60)+degree

If I do the above conversion it gives me the metres and if I plot them in GIS they are shown exactly where the other "Go to XY" shows me.

That is why I believe my conversion is ok.

What should the problem be?

I am really confused and I do not know any other trick to make the job

Many thanks

Re: lat and long

ChristopherMcClain — Thu, 08 Jun 2017 15:27:17 GMT

Did you specify the format as Degrees Decimal Minutes in the Go to XY tool?

Re: lat and long

francescarusso — Thu, 08 Jun 2017 15:41:12 GMT

Yes I have.

I find strange that either the Go To XY tool and my conversion are working the same and taking me to the wrong place...

Re: lat and long

ChristopherMcClain — Thu, 08 Jun 2017 15:48:57 GMT

Where did the coordinates come from? If you choose the Identity tool and click on where the point is supposed to be what is the location given? Do you have a the correct spatial reference defined for your map?

Re: lat and long

AbdullahAnter — Thu, 08 Jun 2017 21:06:57 GMT

Why do you want to convert your coordinate to use Go To XY tool, if you can change the unit in the tool itself?

Re: lat and long

MelitaKennedy — Thu, 08 Jun 2017 21:16:01 GMT

How far off are they? If you identify/click where the point should be, what are the coordinates?

They're still in degree, by the way, not meters.

Re: lat and long

JayantaPoddar — Thu, 08 Jun 2017 21:16:27 GMT

Ensure the coordinate system of the Data frame is a Geographic Coordinate System (like GCS_WGS_1984).

Also ensure the notation is correct.

Longitude/X: East is + while West is -

Latitude/Y: North is + while South is -

Re: lat and long

francescarusso — Fri, 09 Jun 2017 08:37:06 GMT

Thank you everyone.

As I said I have lots of gaps in carthography so because I was desperate yesterday before your comments came in I tried to put a " - " up front the coordinates 1°46.4.And it did work!

I was able to do the job as my coordinates where just 8 vertices of a polygon but my question is: If I have many coordinates like the above (with a N and W), how can I convert them in metres all together?( rather than identifying one by one with the Go To XY tool)

Many thanks for all your useful suggestions and tips.

Cheers,

Re: lat and long

DanPatterson_Retired — Fri, 09 Jun 2017 08:40:44 GMT

perhaps convert-coordinate-notation it exists for arcmap and PRO but it only works on data in a table

Re: lat and long

JayantaPoddar — Fri, 09 Jun 2017 08:53:10 GMT

You could use Convert Coordinate Notation with appropriate Coordinate Format.

Once you get the point feature class, you could reproject it into a projected coordinate system (UTM, Web-Mercator, etc.) whose units are in Meters.

Re: lat and long

francescarusso — Fri, 09 Jun 2017 09:39:37 GMT

Hi,

Of course I had to put the "-" upfront to all my values in the table before importing them with the Convert Coordinate Notation tool but it worked!

Really appreciated your help,

Cheers