Questions tagged [proj]

A library for performing conversions between cartographic projections.

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Proj Oblique Mercator two-point method very useful?

I am happy with Proj oblique Mercator Azimuth (+alpha) method, but I am also itching to try the two points method. But just like @ralph-tee showed in https://gis.stackexchange.com/a/337169/77230 , the ...
Dan Jacobson's user avatar
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Reproject pseudo Plate-Carree to "Icosahedral Snyder Equal Area" using GDALWARP

Reproject pseudo Plate-Carree to "Icosahedral Snyder Equal Area" with gdalwarp. I am trying to reproject a plate-carree to ISEA "Icosahedral Snyder Equal Area". I suspect ISEA ...
Molly's user avatar
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R sf package - upgrade PROJ

Using Rstudio, I need a projection that is not available in the PROJ version I have (see that question). > library(sf) Linking to GEOS 3.11.0, GDAL 3.5.3, PROJ 9.1.0; sf_use_s2() is TRUE I would ...
J Lal's user avatar
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Proximity distance calculation error

I am trying to calculate the proximity distance for my road layer. I have already converted the vector layer in raster, with the units in meters. However, when I try to run the proximity distance tool,...
Richa Adhikari's user avatar
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Projections for Iowa South are now inaccurate (EPSG, SpatialReference)

Sometime in the last 30 days (maybe longer), the projections being provided on e.g. SpatialReference.org and EPSG.io are inaccurate for epsg:3418. (Iowa South) and maybe others? https://...
Josh Larson's user avatar
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How do I reproject without an EPSG code?

I have a set of points that I need to project, but can't find the EPSG code. (EPSG have made it so easy I never had to work with non-built-in codes..) library(sf) Linking to GEOS 3.11.0, GDAL 3.5.3, ...
J Lal's user avatar
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What is the proper syntax in gdal_translate to change image.png to a geotiff by assigning latlong pairs to pixels?

I cannot find comprehesible documentation on how to assign latlon to pixels in an orthogonal image that must be made into a proper geotiff. INPUT kat.png (ORDINARY) OUTPUT kat.tif (GEOTIFF) 512px by ...
Molly's user avatar
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Transform coordinates from ITRF2014 (2020.39) to ITRF2008 (2010.0) using PROJ4?

Due to the fact that I cannot convert the coordinates obtained at epoch 2023.39, X = 1710698.054 meters; Y = 3046082.270 meters; Z = 5318707.282 meters, I still cannot understand how to use in this ...
El_Faie's user avatar
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Error trying to translate raster image from EPSG:3857 to EPSG:3068 with GDAL with subwindow

I'm new with this GIS stuff and starting work with GDAL. I'm using this TMS dataset and trying to project to a specific subwindow like this: <GDAL_WMS> <Service name="TMS"> ...
fmenegussi's user avatar
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Pyproj Azimuthal Equidistant (AEQD) transformation always gives a small rotation as compared to country-specific CRS transformations

I am calculating building polygons from a satellite image. This works accurately when using a country-specific CRS. I would like to use a customer CRS, specific to the location at hand, but find that ...
robkew's user avatar
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How to interpret inputs to General Oblique Transformation in proj?

I am trying to use the General Oblique Transformation to create a projection that is a rotated Oblique Mercator ... but I cannot for the life of me figure out what on earth that thing is doing. I ...
Ajean's user avatar
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How to define a local projection with correct altitude for correct area-metrics

Using PROJ, and defining custom projection, by its PROJ-strings. How to correct WGS84 altitude, to my "fit to local" reference? For example this Albers projection for Brazil: +proj=aea +...
Peter Krauss's user avatar
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About CRS and map origin setting, What is their relation and math equation in leaflet.js via using proj4leaflet.js

I meet a problem about CRS function and map origin setting in leaflet. I use proj4leaflet.js as the basic CRS function, and then after setting the origin of crs and resolution, I can get the correct ...
abramhum's user avatar
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gdaltransform Cartesian transform change 2.2.0 to 3.4.1 proj.4 to?

Here are my results with 2.2.0 and 3.4.1. Can someone explain why this has changed? echo -e "6720419.518191041 1878355.8391366536 1387.976960406033" | \ gdaltransform \ -s_srs "+...
Shanteva's user avatar
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I am getting wrong north and east values after cartographic projection using PROJ library in C++

I am getting incorrect north and east values after cartographic projection from global WGS84 crs(i.e., EPSG:4326) to CRS Korean 1985/West Belt using PROJ C++ library. I got an error of approx. 1.5 cm ...
Rohith dreamtns's user avatar
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56 views

Creating local coordinate system in QGIS

I am trying to create my own coordinate system in QGIS. My local system is defined as: base is Sweref 99 20 15 and then Helmert transformation with these parameters: // Local transformation ...
Petr's user avatar
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3 votes
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Is there a way in PyQGIS to bypass the identify functionnality of QgsCoordinateReferenceSystem creation?

While implementing a geodetic buffering system similar to Approximating Geodesic Buffers with PyQGIS I noticed the buffering is extremely slow. with Timer.context(msg="buffered_geom_function"...
Kalak's user avatar
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OpenLayers PROJ4JS projection of OSM layer is slightly translated?

I am new to OpenLayers and haven't been able to figure out this problem by searching online. I am using a custom projection in OpenLayers 7.4.0 with proj4 2.9.0 as demonstrated in this example. The ...
pklaassen's user avatar
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Axes labels/names of QgsCoordinateReferenceSystem

Consider the following CRS as examples: QgsCoordinateReferenceSystem.fromEpsgId(4326) QgsCoordinateReferenceSystem.fromEpsgId(25832) QgsCoordinateReferenceSystem.fromEpsgId(3857) ...
bugmenot123's user avatar
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Problems recovering 3d mesh from GeoTIFFs created from PDS IMG/LBL files using gdal_translate

Update: I've discovered that the problem lies in the pixel scale. For example, when I use `gdalinfo LDEM_512_90S_45S_000_090.tif` it shows the following for the pixel scale values: Pixel Size = (59....
Chris Gnam's user avatar
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OpenLayers 7 WFS 1.1.0 not drawing polygons when srsName contains opengis.net/gml/srs/epsg.xml

I'm writing a web app that uses WFS data on top of OpenLayers with OpenStreetMap. The entire project works in EPSG:2180 projection and uses multiple versions of WFS (depending on server). OL doesn't ...
T3chnoM4ciej's user avatar
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174 views

How to convert point in any CRS to cartesian XYZ given the proj4 string?

I have GeoTIFFs of other celestial bodies, such as the moon, and am writing a program in C/C++. I cannot use GDAL but I can use libgeotiff, libtiff, and proj. Some GeoTIFFs are in a polar ...
Chris Gnam's user avatar
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138 views

Generating 3d points from GeoTIFF using libgeotiff and proj

I'm working on a C++ library where I need to ingest several different DEM formats (such as GeoTIFFs, SPC Maplets, and some other internal formats) and convert them to a 3d triangular mesh. In the ...
Chris Gnam's user avatar
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33 views

QGIS 3.22 support for topocentric CRS

I simply try to convert a point from local Cartesian ENU centered on a point with lat,lon coordinates to geocentric ECEF coordinates. With proj from command line all works well. I use strings from ...
Gab74's user avatar
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Projection is not found when importing PostgreSQL file with Geopandas

I need to import a couple of files from my PostgreSQL database, which has columns with the geometrical data stored in the CRS "epsg:1330". There are no problems with opening the files using ...
Idalh's user avatar
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Reprojecting NetCDF file from LCC to WGS84: 'Multiple grid mappings exist' error

I try to reproject a NetCDF file to WGS84 so I can clip it with a regional geometry for analysis. The file is a dataset with the CORDEX precipitation variable, climate change scenario rcp 2.6, years ...
Dio Nik's user avatar
3 votes
2 answers
254 views

Using NTv2 gridfiles in QGIS >= 3.22.x LTR with proj 9.x

This question is a follow-up to QGIS transformation defined in srs.db tbl_datum_transform table not available in Select Datum Transformations dialog Basically it is all about making an NTv2 gridfile (*...
Jochen Schwarze's user avatar
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253 views

How do I use a .gtx file in pyproj?

I want to use the egm08_25.gtx file to convert from ellipsoidal height above goid. from pyproj.transformer import TransformerGroup t = TransformerGroup('EPSG:4979',"+proj=longlat +datum=WGS84 +...
sehan2's user avatar
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How to convert wgs84 from ellipsoidal height to mean sea level i.e. height above goid, with pyproj?

I want to convert wgs84 coordinates with ellipsoidal height to wgs84 coordinates with height above goid. Therefore I have set up a new conda environment and installed pyproj, proj_data, see conda list ...
sehan2's user avatar
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Why are x and y switched here?

I'm trying to convert between EPSG:7665 and EPSG:32145, but I have to swap the x and y values to get the correct answer. From this datasheet reference point, here's the position: OD1097* NAD 83(2011) ...
Crag's user avatar
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2 votes
1 answer
98 views

PROJ Helmert temporal ETRF2000 to ITRF2014

Just installed PROJ (Rel. 8.2.1) and GDAL (3.4.3), so apologies for my newbie questions as not found many examples of time based transformations. I have a FILE with the following coordinates in ...
marky9074's user avatar
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198 views

Query UTM grid for elevation at specific lat/lon coordinates

I need to query UTM grid data (25 meters) for elevation at specific coordinates in lat/lon form. The UTM data uses the following proj parameters: +proj=utm +zone=32 +datum=WGS84 +units=m +no_defs. I ...
wullxz's user avatar
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2 votes
1 answer
218 views

Incorrect coordinate conversion results from ProjNET when converting across horizontal datums

Been fighting this for almost a week now, so I'm hoping that someone here has some insight or can tell me the obvious thing I'm missing. I am trying to add programmatic coordinate conversion on the ...
Ruud A.'s user avatar
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British National Grid shapefile prj subtle differences change polygon accuracy

I'll preface this question with the statement I know very little about projection systems so this is coming from a position of total ignorance. I have two shapefiles. One is in England and one is in ...
Titan's user avatar
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Error in projNET and DotSpatial projection to EPSG:2950 coordinates

I need to convert a point from EPSG:4326 to EPSG:2950. But I am consistently getting a wrong result. On the platform I’m using I can only use the following libraries: projNET (link) DotSpatial (link) ...
Mitch_V's user avatar
1 vote
1 answer
463 views

Transforming point from EPSG:3844 to EPSG:3857 with proj4js

I'm having an issue transforming a point from EPSG:3844 to EPSG:3857 using Proj4JS. The transformation it performs seems off compared to the result given by PostGIS, pyproj, rgeo-proj4 or even epsg.io....
mrk's user avatar
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1 vote
1 answer
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Correct parameters to visualize WMS layers in Leaflet and proj4?

I'm struggling to visualize WMS-layers from a REST service using Leaflet. All I see currently is a gray map, not changing anything when moved. The layers I want to visualize are located in Faroe ...
Ólavur Nón's user avatar
1 vote
1 answer
71 views

Are there any limitations on the functionality of PostGIS related to the version of PROJ?

PROJ >= 7 optionally requires curl and libtiff. Are there any limitations on functionality of PostGIS if PROJ is not installed with them which are optional? I would like to use all functionality of ...
kzshiba's user avatar
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User Select CRS Tool

I am trying to create a tool which lets the user select a Coordinate Reference System from a list to project their data to. Are there any available libraries (preferably JS), datasets, or API's which ...
rosewall's user avatar
1 vote
1 answer
114 views

Issue with swapped axes using projinfo/gdaltransform

I'm attempting to perform a coordinate transform operation using gdaltransform (version 3.6.0). Because of the possibility of different transform candidates when the transform involves a change in ...
plet's user avatar
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ST_Transform in PostGIS not working on Linux, GDAL 3.5.1, but working on MacOS, GDAL 3.5.3

I have a raster in PostGIS that has a non-standard projection, namely select srid,proj4text from spatial_ref_sys where srid=9822; srid | proj4text ...
Jon Riecke's user avatar
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1 answer
193 views

Cannot find OSTN15_NTv2_OSGBtoETRS.gsb

I'm running Proj 6.3.1 When running projinfo -s epsg:27700 -t epsg:4326 Is see Grid OSTN15_NTv2_OSGBtoETRS.gsb needed but not found on the system. Can be obtained from the proj-datumgrid-europe ...
Daniel van der Maas's user avatar
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Pyproj transformation of a geopandas does not match QGIS reprojection

I have a file in British National Grid coordinates (EPSG 27700) which I'm trying to convert to WGS84 (EPSG 4326) My first attempt was to transform in the usual way import geopandas as gpd file = '...
Daniel van der Maas's user avatar
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0 answers
71 views

Arbitrary spatial rotation (Euler/Quaternion) using Proj transformation

I’m a geologist who is working with paleogeographic reconstructions (see example here). These require composite reproductions where different parts of a feature dataset (continents) are rotated with ...
Daven Quinn's user avatar
2 votes
3 answers
1k views

QGIS Error between EPSG and custom SRC

This is an error I get since the day I changed to 2.x to 3.x version. Today, I am trying to fix it. I had QGIS 3.10 on Linux Mint from the repositories. Then, I have uninstalled all, and I have ...
exodehm's user avatar
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Combining affine transformations and COMPOUNDCRS

I have a need to define a WKT CRS which is both affine-transformed in 2D, and vertically shifted in the height direction. What I would like to say is something like this: COMPOUNDCRS["Modified ...
Pseudonym's user avatar
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1 vote
1 answer
207 views

Which temporary projection is most suitable for calculating a buffer around a route

To create a buffer around route (for purpose of querying around a route), I figured I need to: convert route points from geographic to planar coordinates calculate a buffer convert result back to ...
zigzag's user avatar
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0 votes
1 answer
114 views

Reproducing SWEREF99 to ITRF2014 Transformation using proj.org cct

The Swedish Geodetic Agency Lantmateriet provides a document (see references) with a procedure for transforming coordinates between ITRF2014 and SWEREF99. The document also provides and example of the ...
Damien's user avatar
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2 votes
1 answer
326 views

PDAL +init use deprecated but what is the alternative

With PDAL I was trying to using a proj4 string like +init=epsg:32615 +geoidgrids=C:\vdatum_GEOID12A\vdatum\core\geoid12a\g2012au7.gtx based on an example given on the PDAL website https://pdal.io/en/...
TJR's user avatar
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1 vote
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190 views

Transform latitude and longitude to Transverse Mercator

I would like to transform point in WGS84 lat lon to Transverse Mercator: +proj=tmerc +lat_0=0 +lon_0=114 +k=1 +x_0=-49099.65399999998 +y_0=-2544749.4072 +ellps=WGS84 +units=m +no_defs I could easily ...
Ethan's user avatar
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