# Converting UTM to EPSG:5389

**URL:** <https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280>\
**Category:** Geo\
**Tags:** question, archgdal, geodesy\
**Created:** [September 14, 2022, 3:57pm UTC](https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280 "2022-09-14T15:57:33Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![ameresv](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ameresv/32/14372_2.png) [@ameresv](https://discourse.julialang.org/u/ameresv)\
**Post date:** [September 14, 2022, 3:57pm UTC](https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280/1 "2022-09-14T15:57:33Z")

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It could sound like a silly question, but I am having trouble converting points from UTM to long - lat (researching a bit, I found that I need is EPSG:5389 because is on the Southern side of Peru).  
So, the data looks like [this](https://raw.githubusercontent.com/ameresv/data_share/main/data.csv). In that way, many questions came to my mind:

- I can create a polygon with the data shared; however, is advisable to first convert them to EPSG and then create the polygon?
- Is there a way to convert all the coordinates of the polygon without unmerging them?

In any case, any suggestion that you can give me about the conversion will be highly appreciated.  
Warm regards from Peru

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**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [September 14, 2022, 7:55pm UTC](https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280/2 "2022-09-14T19:55:48Z")

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Could you confirm what is the source of your coordinates and the coordinate reference system where they are defined? The numerical values do not make sense to me.

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**Author:** ![ameresv](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ameresv/32/14372_2.png) [@ameresv](https://discourse.julialang.org/u/ameresv)\
**Post date:** [September 14, 2022, 8:03pm UTC](https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280/3 "2022-09-14T20:03:22Z")

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HI @rafael.guerra. Thanks for the comments.  
Checking the original database, the data looks like this  
 ![image](https://global.discourse-cdn.com/julialang/original/3X/8/b/8bac0693a4e27cf6091a5e5f793449dbf48b06ca.png)  
Then, I added the first one with the third one, the second one with the fourth one and so on in order to obtain the data presented.  
If you plot those on an excel file, you will find a perfect polygon in UTM.  
Regards

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**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [September 14, 2022, 8:10pm UTC](https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280/4 "2022-09-14T20:10:27Z")

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In the UTM system, if I am not mistaken, `0 < X < 1_000_000 m` and `0 < Y < 10_000_000 m`. Your data goes beyond those bounds.

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**Author:** ![ameresv](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ameresv/32/14372_2.png) [@ameresv](https://discourse.julialang.org/u/ameresv)\
**Post date:** [September 14, 2022, 10:13pm UTC](https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280/5 "2022-09-14T22:13:21Z")

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Yes. You are correct.  
Researching a bit further in the data source, I found that those numbers are Msec Long and Msec Lat, respectively  
 ![image](https://global.discourse-cdn.com/julialang/original/3X/4/2/421ee2a00fcb97e8b9477c7473dd8cf018f0151e.png)  
Regards

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<div class="post-metadata">

**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [September 14, 2022, 10:20pm UTC](https://discourse.julialang.org/t/converting-utm-to-epsg-5389/87280/6 "2022-09-14T22:20:54Z")

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In that case, you can divide your lat lon data in milliseconds by `3_600_000` to get lat lon in decimal degrees.