1

I have lat/long and when I convert to UTM, my points are in zones 35 and 36. is it possible to "transform" or "project" (I am not sure which word is used to do this operation) the UTM coordinates from zone 36 to zone 35 ?

Edit: Just to clarify I have those two coordinates.

point 1: is in 35L 460880.04 E 8327740.29 S
point 2: is in 36L 201956.55 E 8375498.52 S

is there any way to say: point 2 is in 35L xxxxxxx E yyyyyy S ?

enter image description here

Guest2015
  • 21
  • 1
  • 4
  • 3
    What GIS software and version are you using? There is a Project tool and a Define Projection tool in ArcGIS. That said, if your lat/long points are actually in UTM 36, you're likely to get some spatial distortion by putting them in UTM 35. Now that also said, every projection has some distortion in area, shape, etc. – recurvata Feb 25 '15 at 17:26
  • If you have a single set of points in lat/long, and you 'convert' them to UTM, they're going to be in a single UTM projection. Some of those points may fall outside the zone, but with a single 'conversion' they're going to be using the same UTM projection. There's no need to change points in one UTM to the other unless you did two conversions originally - the points in 35 zone were projected to that, and the points in 36 to that. The term is project, but if you have lat/long it's probably WGS84 and UTM uses a different datum so you would also need a transformation. – Chris W Feb 25 '15 at 22:14
  • If trying to pick a UTM zone to use, select the one that either has the most points in it or has the least number of points at the farthest distance from the zone boundary. Otherwise, select a different projection (or create a custom one) that includes your entire area of interest. Related: http://gis.stackexchange.com/questions/136063/ – Chris W Feb 25 '15 at 22:17
  • 1
    @ChrisW there are apps that will automatically calculate the correct zone per point (just not any Esri ones!). – mkennedy Feb 25 '15 at 22:57
  • @mkennedy Interesting - does it become an attribute or get split into separate files? While they sound handy in determining zone, as far as I know you can't have a single point file with data in two different (correct) projections at the same time, right? I suppose the distinction is whether we're working with geometry data or just tabular data (ie, you get a list of UTM coordinates for each point, and those coordinates are specific to the correct UTM, but if you loaded them all at once as points it would treat them as the same zone - unless it can read a further zone attribute). – Chris W Feb 25 '15 at 23:18
  • @ChrisW I'm thinking more of tabular / attribute data. Someone could write an Excel-based converter for example. MGRS converters work the same way--each point is treated separately for figuring out the UTM zone. – mkennedy Feb 26 '15 at 00:11
  • @mkennedy Gotcha. Good thing to point out either way, as I wasn't even considering the possibility it might be only tabular source as opposed to geometric. – Chris W Feb 26 '15 at 00:18
  • Sorry, I press enter before I wanted. Thanks for the comments. I am not using any software, I am developing my own application. I have lat/long and I convert to UTM and the points are in two different zones. I have to create a las file with those points, but I have to put in the header the zone that the points are in. So that is why I need to have all the points in the same utm zone. – Guest2015 Feb 26 '15 at 08:57
  • What does it mean? how can I do this? (maybe is what I need...) " but with a single 'conversion' they're going to be using the same UTM projection " – Guest2015 Feb 26 '15 at 09:15
  • It means that without knowing how you are converting from lat/lon into UTM it is hard to advise - I was assuming you had point geometry in a GIS. Based on your edit it would appear you have used a converter (or method or library in your app) that gives the proper UTM zone as mkennedy mentions. Yes, you can get them to the same UTM projection but you will need something in your app that can reproject data (so it converts UTM 36 into 35) or you need a way to override the automatic zone detection in your current conversion from lat/lon and force it to use the zone you want. – Chris W Feb 27 '15 at 01:48

2 Answers2

3

Since you didn't specified which software you re using I'm assuming that is either ArcGIS or QGIS.

ArcGIS: you can change the Later's coordinate system by right-clicking it on the table of contents and choosing another UTM zone, this only changes the view a not the data it self. to change the data's coordinate system use the Project tool under Data Management Tools, DO NOT USE THE DEFINE PROJECTION TOOL IF YOUR DATA ALREADY HAS A PROJECT INFO! (this would mess your data beyond pretty bad) Help Docs

QGIS: right-click the data and open its properties choose a new coordinate reference system. After this just right-click the data again and re-saved it. If you only want to change the view go to Project on the top and open the project's properties, you can choose different coordinate systems there.More info

For the records: next time try to add more info on your question such as which software you are using, etc.

Ricardo Oliveira
  • 283
  • 3
  • 14
2

You can project latitude-longitude coordinates into any UTM zone you want. If you know that you're displaying a map in zone 35 South but there are coordinates that would normally fall within zone 36 South, just project them into 35 South instead.

If your display was in some other coordinate system, "Pseudo-Mercator", EPSG::3857, and the incoming points were UTM 35 South, you would have to reproject them as well.

You could display everything in a single UTM zone or some other projected coordinate reference system, but LABEL the positions with the appropriate UTM coordinates, as you did in your image.

mkennedy
  • 18,916
  • 2
  • 38
  • 60