Area units for output polygon in WGS 84 UTM Zone 32N using QGIS


I am calculating the area of my polygon and I have used WGS 84 UTM zone 32N to calculate the area (using geometry on the field calculator) of my polygon, and I obtained 745461 (without units).

How do I determine whether it is in square metres or square kilometres?

Does ETRS89 and UTM use the same zone (longitude and latitude)?


I’m building an app for the european country Denmark exclusively and I need to retrieve some geospatial data from a (geo)server.
I’m currently trying to determine wether UTM and ETRS89 uses the same zone (lng, lat) or if it varies in regards to Denmark especially?

An example for a UTM Zone for Denmark would be: 32U

Converting UTM to Lat Long inside a Game Engine(Untiy 3d)


This is my first post on Stack Exchange.

I have exhausted my research through the game engine forums, so I am trying this forum since you guys seem to be the experts.

I have an external device that is feeding in UTM grid coordinates into the computer and using Unity 3d Game Engine: www.unity3d.com. This is a VR type project.

Im using C# and Javascript, those are the two accepted languages in Unity. I have found this code for C# online and have tried working it to my project but there seems to be some conversion into the engine errors that im struggling with. Here is the code I found, is this something I can use or will it not work in this context?

Basically I want to plug in my UTM coordinates and spit out Lat/ Long.

Hopefully it is that simple to setup and I have provided enough information about my project.

 public class NewBehaviourScript : MonoBehaviour {
     public double utmEast; //The updated UTM Easting
     public double utmNorth; //The updated UTM Northing
     public string utmZone; // The updated UTM Zone user is currently in. 

     public static void ToLatLon(double utmX, double utmY, string utmZone, out double latitude, out double longitude)
     {
     bool isNorthHemisphere = utmZone.Last() >= 'N';

         var diflat = -0.00066286966871111111111111111111111111;
         var diflon = -0.0003868060578;

         var zone = int.Parse(utmZone.Remove(utmZone.Length - 1));
         var c_sa = 6378137.000000;
         var c_sb = 6356752.314245;
         var e2 = Math.Pow((Math.Pow(c_sa, 2) - Math.Pow(c_sb, 2)), 0.5) / c_sb;
         var e2cuadrada = Math.Pow(e2, 2);
         var c = Math.Pow(c_sa, 2) / c_sb;
         var x = utmX - 500000;
         var y = isNorthHemisphere ? utmY : utmY - 10000000;   
         var s = ((zone * 6.0) - 183.0);
         var lat = y / (c_sa * 0.9996);
         var v = (c / Math.Pow(1 + (e2cuadrada * Math.Pow(Math.Cos(lat), 2)), 0.5)) * 0.9996;
         var a = x / v;
         var a1 = Math.Sin(2 * lat);
         var a2 = a1 * Math.Pow((Math.Cos(lat)), 2);
         var j2 = lat + (a1 / 2.0);
         var j4 = ((3 * j2) + a2) / 4.0;
         var j6 = ((5 * j4) + Math.Pow(a2 * (Math.Cos(lat)), 2)) / 3.0;
         var alfa = (3.0 / 4.0) * e2cuadrada;
         var beta = (5.0 / 3.0) * Math.Pow(alfa, 2);
         var gama = (35.0 / 27.0) * Math.Pow(alfa, 3);
         var bm = 0.9996 * c * (lat - alfa * j2 + beta * j4 - gama * j6);
         var b = (y - bm) / v;
         var epsi = ((e2cuadrada * Math.Pow(a, 2)) / 2.0) * Math.Pow((Math.Cos(lat)), 2);
         var eps = a * (1 - (epsi / 3.0));
         var nab = (b * (1 - epsi)) + lat;
         var senoheps = (Math.Exp(eps) - Math.Exp(-eps)) / 2.0;
         var delt = Math.Atan(senoheps / (Math.Cos(nab)));
         var tao = Math.Atan(Math.Cos(delt) * Math.Tan(nab));

         longitude = ((delt * (180.0 / Math.PI)) + s) + diflon;
         latitude = ((lat + (1 + e2cuadrada * Math.Pow(Math.Cos(lat), 2) - (3.0 / 2.0) * e2cuadrada * Math.Sin(lat) * Math.Cos(lat) * (tao - lat)) * (tao - lat)) * (180.0 / Math.PI)) + diflat;

         print(latitude);// Looking to display in the Console Log Lat.
         print(longitude);// Looking to display in the Console Log Long.
     }
 }

Converting entire map to UTM 18 if only interested in part that is in UTM 18?


I am using some polygons and rasters whose initial extents cover all of Canada or all of North America. I am interested in a small area in Ontario that is in UTM zone 18. I would like to use the UTM 18 projection for this project. If I convert all of my layers into WGS84 UTM 18 using ArcGIS, obviously the parts of the layers outside of the UTM 18 zone will be horribly distorted. I will be cropping the layers after to only my zone of interest once they are all in the same projection. But will the part of the map that is actually in UTM zone 18 be distorted as a result of the reprojection of the entire span of Canada, or will this part be fine?

How to format the labels of a UTM Grid in a map Layout/Print Composer


I am doing a map in for a small area (1.5km by 1.5km on UTM zone 14N). I want to know if it is possible (and how to do it) to format the labels of a UTM grid. This is exactly what I want to show

a) On the Southwest corner of the map I want to see the full value of the coordinates (north or east). I want that the east coordinate shows the first 3 digits in a bigger font than the las 3 digits. For north coordinates I want the labels to show the first four digits in a bigger font than the remaining three digits. I also want them to show the suffix E or N accordingly

b) For the remaining east and north coordinates I just want to show the last 3 digits of the coordinate

I can use either QGis or ArcMap.

I tried to use ArcMap’s grid styles, particularly the USN National Grid and I have no luck. I also tried to use corner style labels feature no luck also

Difference between UTM 10U and UTM 10N? [closed]


I there a difference between UTM 10U and UTM 10N?

ArcGIS has 10N, but my scan map has 10U?

When I attempt to georeference, my scan gets skewed

Can I use Redfearn's formula to convert between WGS84 and UTM?


I have GPS data at 1 point per second for several weeks in WGS84 latitude/longitude form. It was collected using a UBLOX GPS in 2015 in Australia (Zone 55s)

Would it be correct to use Redfearn’s formula to project WGS84 data to Northings/Eastings? Normally it seems that Redfearn’s formula is used with GDA94 rather than with WGS84:

I would like to get Northings/Eastings in meters. The data is only accurate to 2-5m at the moment, but I don’t want to make it worse so would need to use a conversion that is accurate to within a few cm.

I could just use the ArcMap (ArcPy) projection but since I have very large files (1 point per second) even ArcPy is very slow. Therefore I’d rather put the formula directly into Python. I’ll probably use ArcPy later to check some of the results.

The data is collected on animal collars (in Zone 55s). The collars could be used anywhere in Australia (or possibly overseas) so I’d like to use a formula that could be transferable to another part of Australia (although that could involve user input about approximate location).

I’ve also been investigating how to convert WGS84 (presumably = ITRF2008?) into GDA94 and then to MGA, but this seems very complicated and I think it may be simpler just to work in WGS84 UTM since I don’t really need it for an official map.

What is most accurate coordinate system for calculating areas of polygons?


I have multiple polygons, all located offshore around the UK. I am trying to calculate the areas of these polygons in square kilometres, without splitting them by UTM zone.

Is it possible to do this accurately? I have been using World Mercator, but there are big distortions at this scale. If the polygons were limited to the east coast, say, I would use UTM31N. However, as they are all over the UK waters, I am unsure what to use.

Is there a coordinate system that covers this area? British National Grid does not extend far enough out to sea to be of use.

Measuring distances when crossing UTM zones?


I like to calculate distance between two UTM coordinates which are in different zones. Could any one point me how I can do this.

I found that we can map these coordinates in to a new projection for solving the problem. Could any one let me know which is the best map projection where cartesian coordinate related calculations are applicable like UTM.

If some points me to extended UTM zones and how it helps, that will also be very helpful.

Which UTM zone to use for a large country?


I want to reproject OpenStreetMap roads data from the current projection (WGS 84) to UTM, since I read in another GIS.SE discussion (How to get $length in meters in QGIS?) that WGS 84 cannot be used to measure length in m or km. My end goal is to calculate the total roadway kilometres within each district, so that I can enter that variable into my regression model. The country in question is Indonesia, and as you can see from the map below, it covers UTM zones 46-54.

UTM zones map from Wikimedia

Image source: Wikimedia, http://upload.wikimedia.org/wikipedia/commons/e/ed/Utm-zones.jpg

Does it really matter which one I choose? Can I choose the one that’s roughly in the middle and call it good (that would be zone 50) or should I pick the zone that is more densely populated with roads (Jakarta/Java, zone 48)?

I am only barely functionally literate in GIS. The only formal training I had was a 3-day course back in 2008. Really, the only reason I need the roadway kms variable was because one of my thesis committee members wanted me to account for it in my model…

And to confirm, once I have reprojected to the UTM CRS, I can use my GIS software’s built-in length tool to directly calculate the length in metres (or divide by 1000 for km), right?

I am using QGIS.

Question and Answer is proudly powered by WordPress.
Theme "The Fundamentals of Graphic Design" by Arjuna
Icons by FamFamFam