Questions tagged [proj]

A library for performing conversions between cartographic projections.

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1answer
10k views

Convert GPS coordinates to Web Mercator EPSG:3857 using python/pyproj

I've created a couple of functions using the math package from python 3.5 to transform GPS coordinates to x/y web mercator (pseudo mercator) as explained here: http://wiki.openstreetmap.org/wiki/...
3
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1answer
242 views

custom equal area projections with proj4

I need to define equal area projections for various countries around the world (in proj4 terms). I’ve taken a stab and designing them myself but would like to verify that my method is correct. For ...
0
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1answer
494 views

Loading library (rgdal) on windows? [closed]

I just started in the R field. I installed R project and then R studio. I want to execute a process with library (water) and I need before calling RGDAL and I get the following error: library("rgdal"...
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1answer
185 views

proj4.js convert projection from 82397 to 4326

how to add utm84 51n to proj4 So i see something like this proj4.defs("mySphere", "+proj=longlat +lat_0=0 +lon_0=0 +x_0=0 +y_0=0 +a=12345 +b=12345 +units=m +no_defs"); i want to add proj4.defs("...
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0answers
413 views

EPSG 4326 to 3857 works on X axis but not Y with PROJ4NET

I am trying to convert a EPSG:4326 Lat Long into a EPSG:3857 reference. I have looked all around and have found slight differences in WKTs but nothing with different values. The following code ...
3
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1answer
4k views

OpenLayers and proj4js.defs() - why does one custom projection work and not the other?

The javascript at https://jsfiddle.net/nsands/kvhcuL72/ is the simplest demonstration I've come up with for this issue. It is based on OpenLayers example code, but I've defined the map projection ...
1
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1answer
647 views

Proj4 Convert any CRS to ECEF

How can I convert a point in a given CRS I know, to ECEF, using Proj4? Is there an EPSG code for ECEF coordinates? Or is there a way to create a proj4 transform object to convert from and to ECEF ...
1
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1answer
112 views

AHPS proj4 for QGIS

The existing AHPS netCDF files available here: https://water.weather.gov/precip/p_download_new/ do not include a projection...instead they're described as being in an HRAP coordinate system. Further ...
1
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0answers
137 views

Proj.4 get 3x3 or 4x4 projection matrix

How can I get a 3x3 or 4x4 transformation matrix between two CRS, using the proj4 library in C/C++? It's OK if it makes some approximations.
4
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2answers
7k views

How to get map units to find current scale in OpenLayers?

I need my OpenLayers application to be able to determine the current scale. This is not for display (there is already the scale line for that). This is because I have a scale-dependent style ...
2
votes
2answers
547 views

Why are conversion results from proj.4 inaccurate?

I want to convert a Gauss-Kruger coordinate (EPSG::31467) into a WGS84 coordinate (EPSG::4326) using proj.4. The problem is that the output from proj.4 is very, very inaccurate. Consider the Gauss-...
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0answers
618 views

How to convert ESRI .prj WKT string to Proj4 string WITHOUT GDAL

ESRI shapefiles include a .prj file containing CRS information in Well-Known Text (WKT) format. I'm developing a software in which I need to systematically read shapefiles' CRS information, convert it ...
8
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1answer
195 views

QGIS incorrectly saving polygon with custom CRS, while correctly projecting it on-the-fly

I'm splitting a land polygon up in order to shift the centering of the projection to the Pacific ocean. I manage to successfully cut up the original polygon on the 22 meridian, and it looks fine when ...
0
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0answers
164 views

Wrap CSV lat/long points around 180 meridian in QGIS [duplicate]

I have a CSV file with lat/long coordinates. I also have a custom CRS to center the map on the Indian Ocean. Is there a way for me to force the points to plot on the blank band of the map where the ...
10
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1answer
138 views

Ortelius and Nicolosi projection in QGIS

I am trying to define ortelius oval projection and Nicolosi globular projection in QGIS using proj4 foramt as described in documentation but QGIS is unable to project into these projection even if ...
2
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1answer
601 views

rgdal loads PROJ.4 version 4.9.1 when the updated 4.9.2 is installed

I have been having problems with vectorial spatial data for some time, mostly important to plot SpatialPolygonDataFrames (I asked here: Slow plotting SpatialPolygonDataFrames on some systems). This ...
0
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1answer
680 views

Recreating coordinate transformation from Javascript leaflet map in R Leaflet?

At the bottom is Javascript code and it manages to add a map in the Dutch coordinate system (Rijksdriehoekstelsel). I tried to remake it in Leaflet in R, but for some reason I only get a grey screen......
2
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1answer
598 views

Incorrect transformation when using pyproj

I am using pyproj to work with shp files and am relatively new to GIS. I am tryign to visualize the shp data, but am having a problem as I am incorrectly transforming the coordionates. Here is an ...
1
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1answer
383 views

What does the “zone” stand for in proj?

I am using proj, in particular pyproj, to convert from UTM coordinates to the (x,y) coordinates used, for example, by Google Maps. There is a parameter called zone which I could not understand how I ...
4
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1answer
185 views

Define Proj4 string for CANGRD dataset

I'm trying to georeference the .grd files provided here http://open.canada.ca/data/en/dataset/3d4b68a5-13bc-48bb-ad10-801128aa6604. The documentation states "The CANGRD grid is in polar stereographic ...
2
votes
1answer
867 views

Are there EPSG codes for solving China GPS shift problem?

I am currently using PyProj for a project, and would like to transform from WGS-84 (or other systems) to the China-specific datums for writing into kml files. I have seen other packages specifically ...
3
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2answers
388 views

Python WKT or Proj4 lookup package

I am looking for a Python package that would allow me to input a UTM zone code and output different geo_referencing strings (for example, WKT or Proj4). Are there any lightweight, widely used packages ...
1
vote
1answer
298 views

Getting “Error in par(pin = p)” when using spTransform in R

I am trying to apply a projection to the following dataset from the USGS: https://www.sciencebase.gov/catalog/item/581d052be4b08da350d524ce. After reading in the dataset, the "proj4string" slot shows ...
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1answer
757 views

Accurate Transformation of Gauss Kruger to WGS84 and ETRS89 using PROJ.4

I have to transform Gauss Kruger coordinates to Long/Lat coordinates in WGS84 and ETRS89. I have really no knowledge about all these coordinate systems and their transformations. My background is just ...
1
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0answers
274 views

OL3 with custom projection (Proj4) and wmts

I have a problem with projection in ol3. I want to integrate a wmts layer with projection: EPSG:25832 (UTM 32) using Proj4. I tried to combine the ol3 wmts example : https://openlayers.org/en/latest/...
3
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0answers
509 views

Anaconda UnsatisfiableError installing QGIS

If I run conda install -c conda-forge qgis=2.18.2 from my Ubuntu bash environment, I obtain the following error: UnsatisfiableError: The following specifications were found to be in conflict: - ...
2
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0answers
58 views

mapnik proj4 tpers error

I'm working on a project where we need our tiles rendered with tilt perspective. I have installed and running openstreetmap server and it's working, but I need this projection to work: +proj=tpers +...
2
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2answers
968 views

Custom SRS for openlayers 3 (ol3) without an EPSG code

How can openlayers 3 be told to use and work with a custom SRS-definition which has no EPSG-code? May i don't understand it but it seems like ol3 needs an EPSG- or ESRI-code to work. I found some ...
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0answers
124 views

How to use Local Azimuthal projection to convert Local NED to Geodetic LLA?

I'm trying to use Proj4j.EquidistantAzimuthalProjection to get the latitude/longitude of a new location based on its relative distance and bearing to a known location. Here is my source code: import ...
5
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3answers
366 views

Converting from oblique and non-cartesian custom coordinates system with PostGIS?

I have a custom coordinates system that is: Not cartesian: The X-axis unit is 25m & Y-axis 6.25m Oblique: None of both axis' azimuth is North-South (0°). X-axis goes 54.2° & Y-axis 324°. ...
6
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1answer
2k views

What's this PROJ4 string in WKT?

I have this projection in PROJ4: +proj=tmerc +lat_0=41.836944 +lon_0=-87.684722 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs What's the WKT translation? I saw this site: http://cfconventions.org/...
3
votes
1answer
443 views

GDAL installation problem: Linux server without sudo privileges

I'm having problems installing GDAL on my account on a remote Linux server where I can't use sudo. Ultimately I want to use RStudio and Rgdal, but it looks like I need to install GDAL and PROJ4 first. ...
6
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2answers
1k views

Proj4J not precise for EPSG:3857 transformations

I try to convert some coordinates from "EPSG:31469" to "EPSG:3857" and back. With the heavy framework GeoTools it seems to work pretty precise. "EPSG:31469" - 5439627.33, 5661628.09 "EPSG:...
3
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2answers
4k views

How to fix ERROR 6: Unable to load PROJ.4 library (proj.dll), creation of OGRCoordinateTransformation failed issue

I have installed GDAL in my system. I tried a simple program which uses spatial reference functions. When I tried to execute that program i am facing "ERROR 6: Unable to load PROJ.4 library (proj.dll),...
3
votes
1answer
706 views

Creating a local projection system in QGIS using Proj.4

I'm trying to recreate a local mine grid for the QGIS users within our group. This grid is a modification of the Northing (-8000000). I imported the original UTM zone (35S). What is the function in ...
2
votes
1answer
539 views

How to create proj4.js and proj4leaflet.js for coordinate transformation

I need to know how to create a proj4.js and proj4leaflet.js which requires me to convert coordinates from EPSG:31700 to wgs84. Both scripts I will load in leaflet script.
4
votes
1answer
592 views

What are correct options for converting from state plane nad83 zone NNNN to lat lon in proj4/cs2cs?

I need to build a command line batch converter to read in data from a file that includes coordinates in state plane x,y in feet, the coordinate system used and the zone. For example: cs: nad83 ...
1
vote
1answer
430 views

Creating a geodetic line that goes around the whole ellipsoid with pyproj

https://jswhit.github.io/pyproj/pyproj.Geod-class.html Pyproj's Geod class has a npts method to create points on the geodesic between two points: npts(self, lon1, lat1, lon2, lat2, npts, radians=...
3
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2answers
599 views

Creating local accurate projection for proj4?

We recently discovered that the UTM projection we have been using is not accurate enough for our application when doing calculations that require distances. Instead of rewriting our code base to use ...
3
votes
1answer
584 views

Get EPSG code or CRS name from Proj4 WKT

I am trying to get the EPSG code from a proj4 WKT. :“+proj=lcc +lat_1=46.183333333 +lat_2=47.483333333 +lat_0=45.666666667 +lon_0=-100.5 +x_0=600000 +y_0=0 +ellps=GRS80 +units=us-ft +no_defs” But I ...
1
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1answer
348 views

.prj (Srtext) to proj.4 for custom projection using local grid, error ' no translation for LOcal to proj.4 format is known'

I have to transform the local reference system with the following SRtext parameters: PROJCS["Sagalassos Local Grid", GEOGCS["GCS_WGS_1984", DATUM["D_WGS_1984", SPHEROID["WGS_1984",6378137.0,298....
2
votes
1answer
377 views

Creating CRS with coordinate origin at north-west corner of Mercator projection?

I want to define a custom CRS for a very special, technical use-case. For that I use a WGS84-World-Mercator as base definition, here are the proj4 parameters taken von QGIS: +proj=merc +lon_0=0 +k=1 +...
3
votes
3answers
3k views

Converting decimal degrees (longitude & latitude) to UTM WGS84 in R? (Southern hemisphere)

I'm trying to convert some longitude and latitude coordinates to UTM WGS84 projection. I'm using rgdal, although I can accommodate to other package (in R). I read the data and converted it to a ...
6
votes
1answer
666 views

Custom Projection in Proj4 has errors, what can I do to implement a 4 parameter transform?

I'm working on a project where I'd like to define a projection in QGIS, using a Proj4 string, so that a user can import and export site coordinates from the local UTM or geographic coordinates. I've ...
2
votes
1answer
131 views

Reprojecting data from “arbitrary” coordinate system to state plane

I have been "gifted" a large cache of data (mostly CAD DWG, some TIF based photography) that is in an "arbitrary" coordinate system. I have determined that the system used is the correct NAD27 state ...
4
votes
2answers
473 views

Gdal does not honor proj.4 scaling factor “+k_0”

My problem: I'm currently trying to use gdal to write GeoTIFF files. I'm however having problems with using a proj4 string to describe the projection. ("+proj=lcc +k_0=0.001 +lat_1=46 +lat_2=49 +...
2
votes
1answer
476 views

NAD27 to WGS84 with proj4js

I am trying to use proj4js to convert between WGS84 (4326) to NAD27 BLM 14N (ftUS) (32064). I am using this definition for EPSG 2674 `proj=tmerc +lat_0=0 +lon_0=-99 +k=0.9996 +x_0=500000.001016002 +...
3
votes
3answers
1k views

Convert from EPSG:27700 to latitude and longitude

I'm trying to transform EPSG:27700 coordinates to latitude and longitude. From my research I understand that WGS 84 (EPSG:4326) is the SRS that resembles latitude and longitude. I'm using Proj4j to ...
2
votes
1answer
1k views

Getting extents of spatial reference system using Proj.4?

In general, how does one get the valid extents of a spatial reference system but in particular, is there a way using the Proj.4 library? I attempted to use the information from the epsg.io website, ...
4
votes
4answers
626 views

Generate Proj4 definition from given parameters

I'm an archaeologist and I'm struggling with the generation of a reference coordinate system for georeferencing the Spezialkarte der Osterreichisch-Ungarischen Monarchie (XIX century). I've found the ...

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