Questions tagged [proj]

A library for performing conversions between cartographic projections.

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Reprojecting raster from 0 360 to -180 180 with cutting 180 meridian using gdalwarp

I have a geotiff raster image that has a coordinate system with longitudes from 0 to 360. The horizontal center of the image is 180 longitude. See image below: I want to transform it to EPSG:4326 SRS ...
nextstopsun's user avatar
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24 votes
3 answers
41k views

How can I get the proj4 string or EPSG code from a shapefile .prj file? [duplicate]

I have to work with a shapefile defined in an unusual projection, which my GIS software does not know about. How can I get the proj4 definition or the EPSG code for the projection?
rudivonstaden's user avatar
17 votes
5 answers
26k views

Repairing broken GDAL and PROJ.4 on Ubuntu?

I solved the library problem, but others remain, only vaguely related to that of PROJ.4 libraries are not loaded. I asked a follow-up question for these. My GDAL package and PROJ.4 library are damaged,...
Pavel V.'s user avatar
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16 votes
5 answers
24k views

Build gdal with proj version 6

Description of the issue: Building GDAL from sources after having build proj in its latest version is failing at the configure step because it's not finding proj 6. Details to reproduce: Work ...
swiss_knight's user avatar
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16 votes
4 answers
11k views

What is the best way to programmatically convert between WKT and Proj4 string?

Some shapefiles have a .prj file associated with it, and the .prj file contains the projection info of the shapefile in the format of WKT. Sometimes I need to convert WKT to proj4 string, and ...
Cui Pengfei 崔鹏飞's user avatar
15 votes
2 answers
42k views

Choosing the correct value for proj4string for shapefile reading in R?

I am having a shapefile of polygons and another CSV file which contains a list of points as (Lat, Lng) pairs.. I want to check for each (lat, lng) pair from the CSV file which polygon does it fall ...
Moustafa Alzantot's user avatar
15 votes
1 answer
3k views

Defining Winkel Tripel in proj 4.8.0?

I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as +proj=wintri But that definition string does not work. Is this a bug in my proj version, ...
underdark's user avatar
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15 votes
1 answer
2k views

Integrating NTv2-transformation in QGIS?

I am wondering what's the correct way to integrate a NTv2-transformation in QGIS. I have successfully integrated a NTv2-transformation in QGIS but I am not sure if it's done the way it's meant to be. ...
Thomas B's user avatar
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14 votes
2 answers
9k views

use proj4 to specify Robinson projection with R ggmap and ggplot2 packages?

I want to project this map in robinson projection: library(ggmap) world <- map_data("world") ggplot() + geom_path(data = world, aes(long, lat, group = group)) And I ...
Abe's user avatar
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12 votes
2 answers
5k views

PROJ.4 - General Parameters: +no_defs

Within a QGIS-course I would like to tell a bit about the proj.4 parameters. However, I'm not sure about the "+no_defs" parameter. The proj.4 website (http://proj4.org/parameters.html#parameter-list) ...
Flo's user avatar
  • 624
12 votes
2 answers
2k views

Huge differences between results for 7-param datum transform

I'm trying to transform a WGS84 lat/lon point 11d42'32.10629" E 5d12'56.75371" S in three different software packages (Proj4, GeoTrans and Leica GeoOffice) but I receive very big differences ...
WindRider's user avatar
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11 votes
3 answers
24k views

Converting X,Y coordinates to lat/long using pyproj and Proj.4 returns the wrong coordinates

I'm writing a python script that reads multiple XML files containing x and y coordinates and combines them all into a single csv file. Latitude and Longitude are required fields in the csv, but I am ...
Brian's user avatar
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10 votes
5 answers
6k views

WKT for EPSG:4326 with LON 0 to +360 instead of -180 to +180

I have GRIB2 files that seem to be in a projection similar to EPSG: 4326, except that instead of longitude between -180 and +180 it is between 0 and 360. My intention is to get these files into ...
Mike Furlender's user avatar
10 votes
1 answer
282 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 ...
PetraJ's user avatar
  • 103
10 votes
1 answer
5k views

Solving Gdalwarp error 'too many points failed to transform' for remapping Geostationary to Lambert conformal [closed]

I am trying to remap from Geostationary to Lambert conformal using gdalwarp. My input data is in netcdf, and is in geographic coordinates (degrees) and I would like to output the remapped data to ...
Katie J's user avatar
  • 127
10 votes
0 answers
626 views

How to use a Spilhaus/ESRI:54099 projection in QGIS

I am trying to make a map using a Spilhaus projection, similar to the one implemented by Esri here. QGIS has ESRI:54099 WGS_1984_Spilhaus_Ocean_Map_in_Square in its list of available projections, ...
Ben's user avatar
  • 405
9 votes
1 answer
4k views

How should I handle CRS properly after the major change in PROJ library?

As explained here, the PROJ library has changed a lot and one should stop using proj.4 strings. To me it is not clear, what I should do instead. This answer explains, how I could deal with the problem ...
Christoph's user avatar
  • 279
9 votes
2 answers
3k 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/...
Ben Cooper's user avatar
9 votes
2 answers
318 views

Setting proj parameters of old map

I would like to georeference these fantastic old public domains maps https://legacy.lib.utexas.edu/maps/ams/italy_50k/ I started from this one, and it has these projection parameters. Then I have ...
aborruso's user avatar
  • 1,259
9 votes
4 answers
5k views

Using PROJ.4 library to transform from local coordinate system coordinates to global coordinate system using ground control points?

I have a point cloud whose coordinates are with respect to a local coordinate system. I also have ground control points with GPS values. Can I convert these local coordinates to a global coordinate ...
user18953's user avatar
9 votes
1 answer
10k views

How do I solve a "No PROJ.4 translation" error with gdal?

I've installed gdal using the brew utility on OS X so the proj and geos dependencies were also installed. I'm now trying to warp a GeoTIFF so that I can import it into Google Earth. I am getting a ...
mankoff's user avatar
  • 1,630
8 votes
3 answers
26k 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/...
TPPZ's user avatar
  • 407
8 votes
3 answers
2k views

Adding Equal Earth Projection in QGIS?

There is a new accurate projection for world maps ► Equal Earth. I know its proj4 but I can't add it in QGIS (see below). Does it need some kind of QGIS update?
Dan's user avatar
  • 1,060
8 votes
1 answer
14k views

R-4.0.1 Not sure I understand this message: Warning message: In proj4string(x) : CRS object has comment, which is lost in output [closed]

Context: I want to store the TIFF data to use it for running a linear regression model later on. Ultimate goal: Create a carbon map using field data as a basis. Libraries: library(sp) library(raster) ...
user13608970's user avatar
8 votes
4 answers
2k views

sp::proj4string equivalent in the PROJ6 framework?

I am confused about the shift from PROJ4 to PROJ6 in the (relatively) recent versions of the spatial packages of R (and gdal for that matter). I used to use sp::proj4string() to get the projection ...
Mikko's user avatar
  • 374
8 votes
1 answer
4k views

Are these two OGC WKT projections the same? And if so, why are their reference strings different?

So here is the .prj text of a federal shapefile dataset of all public airports in its native OGC WKT format: GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],...
boulder_ruby's user avatar
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8 votes
4 answers
3k views

Proj.4/GDAL/QGIS Transformation between CRSs that are defined the same

I'm helping to ensure that open source software can handle Australia's new datum appropriately, see ICSM's website for details on the GDA2020 project. Now, QGIS has already got the definitions of ...
Alex Leith's user avatar
  • 13.4k
8 votes
1 answer
417 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 ...
srha's user avatar
  • 829
8 votes
1 answer
3k views

Handling raster data in a "rotated pole projection" with R?

My question is about using R to transform raster data from a rotated pole projection to a regular latlon grid - and then plotting it. I am working with data from a numerical weather model, which is ...
jonaswp's user avatar
  • 141
8 votes
0 answers
1k views

Fuller/Dymaxion in proj4/gdal/qgis?

I know this question has been asked a million times already, but I can't find many detailed responses on exactly what I want to do. As far as I can tell, the full C code for the fuller projection is ...
Alex McVittie's user avatar
7 votes
2 answers
5k views

Transforming geostationary satellite image to lon/lat

The ICARE Data and Services Center distributes the SEV_AERUS-AEROSOL-D3 product in HDF5 format (http://www.icare.univ-lille1.fr/archive/?dir=GEO/MSG+0000/SEV_AERUS-AEROSOL-D3.v1.03/). The main ...
Michael Dorman's user avatar
7 votes
1 answer
871 views

To project, or not to project? Extracting raster values with R

I have a raster from which I need to extract values at point locations using raster::extract(raster_stack, points_sf). The raster is at 30 arc-second resolution and came from WorldClim with ...
Gregory's user avatar
  • 1,661
7 votes
4 answers
2k views

QGIS proj4 definition is not valid

In QGIS 3.4 I'm trying to add a custom projection that was used for topographic maps of Suriname in the 1950s. I have the parameters from an article about historical CRS used in the country. Using the ...
Gin's user avatar
  • 470
7 votes
1 answer
3k views

pyproj, proj4 doesn't return same coordinates after inverse conversion

I'm trying to interpolate between coordinates, as a step in that process I convert latlong to UTM so I can work in metric. I don't get the expected latlong when converting back, reproduced below: &...
Sebastian Jansson's user avatar
7 votes
1 answer
24k views

Assigning CRS to shapefile when it doesn't have one, in R?

I think that by using readOGR to import a shapefile renders worthless to put proj4string to the script since if any coords are available in the shapefile, it will be transported through the readOGR. ...
gsa's user avatar
  • 1,246
7 votes
3 answers
4k views

Does anyone know the proj4 Coordinte Reference System command line for Rectangular Polyconic Gores?

I am a GIS beginner using QGIS 1.8.0 I am trying to transform a world map from the standard WGS84 Coordinate Projection System to a set of rectangular polyconic gores, with a gore count of 12. ...
Martin's user avatar
  • 413
7 votes
1 answer
7k views

How to update CRS r object from PROJ4 to PROJ6

I have a script which contains several r objects which are CRSs that I use for transforming spatial objects. After updating R and many packages, there is a warning which wasn't there before. LCC <- ...
canderson156's user avatar
7 votes
2 answers
2k views

Convert WKT coordinate reference system to PROJ4

I'm currently working on a better support of LAS 1.4 file format in the rlas R package. In LAS 1.4 format the CRS of the point cloud can be stored as a WKT string. For example this is what I read from ...
JRR's user avatar
  • 9,264
7 votes
4 answers
6k views

How to find and apply reprojection parameters?

I have a data set in one projection, and a shapefile in another, and I am trying to combine the two. I am using Python. I apologize for posting a "help me transform coordinates" question on this site -...
mankoff's user avatar
  • 1,630
7 votes
2 answers
9k views

How to perform transformations using ProjNet?

While writing some unit tests I thought it would be convenient/possible to use ProjNet to convert from EPSG:4326 into several other coordinate systems (3875,3395). I figured it would be as easy as ...
ca0v's user avatar
  • 2,931
7 votes
1 answer
10k views

Definitive list of Proj4 supported coordinate systems

I need to determine the minimum set of coordinate systems supported by all tiers of my project's stack. I have a list of EPSG codes supported by Oracle and GeoServer but I'm having trouble finding a ...
tomfumb's user avatar
  • 3,678
7 votes
1 answer
2k views

projection/pyproj puzzle, and understanding SRS format

I have a shapefile that has a .prj file, with the following wkt contents: PROJCS["NAD_1927_StatePlane_New_York_West_FIPS_3103",GEOGCS["GCS_North_American_1927",DATUM["D_North_American_1927",SPHEROID["...
M Katz's user avatar
  • 503
7 votes
1 answer
1k views

Custom transverse Mercator projection with fiona and shapely

AS a build off from this question I posted over a year ago Buffer miles in decimal degrees with fiona and shapely I am attempting to create 50-mile buffers around each earthquake. I have taken the ...
ziggy's user avatar
  • 4,480
7 votes
1 answer
1k views

Specifying PROJ.4 projection with North pointing down?

I would like to create a world map "upside down", with the South on top (in Mapnik). How can I achieve this? Can I take an existing projection string, e.g. Robinson projection, ESRI:54030. +proj=...
Florian Ledermann's user avatar
7 votes
1 answer
8k views

Converting Lambert Conformal Conic to WGS84 using Proj.4

I am attempting to transform data from Lambert Conformal Conic lat/long and I am having some issues with the results. The shapefile I am attemtping to transform can be found here: http://tfr.faa.gov/...
Aaron's user avatar
  • 175
7 votes
1 answer
3k views

QGIS: No transform available error

I installed QGIS 3.16 on Ubuntu-20.04. Details on 'About QGIS': QGIS version 3.16.12-Hannover QGIS code revision be6cb030ac Compiled against Qt 5.12.8 Running against Qt 5.12.8 Compiled against ...
HY K's user avatar
  • 71
6 votes
1 answer
4k views

PROJ.4 How to create custom CRS to displace by x and y?

I'm trying to create a custom CRS with proj4. I need to displace coordinates by adding 10 meters east and 20 meters north from EPSG:32719. How can I do that with PROJ.4?
dfarfan's user avatar
  • 63
6 votes
1 answer
2k views

PROJ.4 cs2cs is too slow. Alternative?

I use PROJ.4 cs2cs to convert data from a Lambert Conformal Conic to a geodetic coordinate (NAD83) or vice versa. In my application, sometimes I need to convert a lot of data. Because I call cs2cs ...
user28857's user avatar
6 votes
4 answers
3k views

PostGis ST_Transform: failed to load NAD27-83 correction file (-38)

So I'm getting some user drawn polygons in WKT with OpenLayers. (Web Mercator CRS) and I now need to now convert it to SRID4326 so can do some spatial queries. However, when it fails to do a ...
Nate's user avatar
  • 811
6 votes
1 answer
76 views

Are proj4 strings case sensitive? [closed]

Is there any reason that case of characters in Proj4 strings would affect their interpretation? Before parsing a Proj4 string, can I lower case all the characters first?
vpipkt's user avatar
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