Questions tagged [coordinate-system]

A reference framework consisting of a set of points, lines, and/or surfaces, and a set of rules, used to define the positions of points in space in either two or three dimensions. This tag also refers to cartographic projections and coordinate system transformations.

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Evaluating map projection scale error

This is related to a previous question How to determine projection parameters when customizing a projection I posted. I am trying to quantitatively evaluate scale distortion associated with choosing ...
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Using transform function in QGIS layer geometry generator?

I'm trying to use the following expression in the geometry generator in a QGIS layer to show a 1-mi boundary around points: buffer(transform($geometry, 'EPSG:4326', 'EPSG:2877'), 5280) However, the ...
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Mapproxy transformation from Web Mercator to WGS84

I want to transform tiles defined in Web Mercator (EPSG:3857) to WGS84 (EPSG:4326) using Mapproxy. Unfortunately the resulting WGS84 map gets more and more distorted to the poles. Here is my ...
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proj4js with geocentric CRS

I am developing a little web app to transform coordinates between CRSs. To do that I am using proj4js, but I notice that proj4js can't work with geocentric CRSs. Is there another tool similar to ...
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The drawing of Thiessen/Voronoi polygon boundaries - are the bisecting lines truly perpendicular?

I am concerned with how QGIS (version 2.8.1) and ArcGIS (version 10.0) draw "perpendicular bisecting lines" when Thiessen/Voronoi polygons are created. When using either program to create these ...
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How to interpolate within defined boundaries of a deformed mesh using R?

My goal is to create an interpolation map of some output model results that are mapped on a deformed mesh (from a numerical simulation). The model results are in an x-y plane (representing coordinates)...
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Do locations “move” when shifting datum?

I hope that this is the right Stack Exchange for this question. I may be oversimplifying this, but I'm looking for verification in my understanding of the following: If I have a spatial dataset in 2 ...
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Preventing ogr2ogr from generating invalid geometries in transformation

I have the following GeoPackage: https://drive.google.com/open?id=1COcGcbZQIsW6NrzuD-K-Kijpvg4BYQ54 I have checked it with spatialite and it does not have invalid geometries. It has a ...
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How to do a Lee’s Tetrahedral Conformal Projection of Antarctic/South pole on QGIS?

I want to do map of Antarctic using the Lee's Tetrahedral conformal map projection as the image below using QGIS version 3.4. Is it possible to make a custom CRS to do it? If yes, what's the ...
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Seeking Public API to get GPS satellite's position?

Is there any public availible API that allows you to retrieve the current coordinates of satellites such as GPS and Galileo? I've only found ways to get Satellites Ephemeries and calculate the ...
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Showing Polar coordinate grid?

I've found some maps for Antarctica https://nga.maps.arcgis.com/home/webmap/viewer.html How can I show polar coordinate grid for it? I've got the grid source code in grid_wgs.js (I use OpenSeaMap ...
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Adding GDA2020 NTv2 transformation to ArcGIS 10.5

The implementation of GDA2020 is drawing near! In an effort to be ready before time I have downloaded the NTv2 Grid Shift Binary (GSB) transformation grid from ISCM (available here) who are the ...
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Wrong reprojecting of a shapefile with to_crs in GeoPandas

When reprojecting an ESRI Shapefile (EPSG:21781) into an EPSG:4326 with QGIS and then importing the resulting file in GeoPandas and plotting it, the coordinates are correct. When importing the same ...
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Local grids with rotated north in QGIS

Like many people in geology and archaeology I need to work with local grids that have eastings and northings from a specific reference point, and typically have a difference alignment/direction of ...
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Re-referencing raster in rotated coordinate system by “de-rotating” it

My Trying to define a "rotated regular grid" coordinate system in QGIS question about this got closed because there was already an answer to it, which I understand. I went to the answer in ...
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Automatically creating user CRS from postgis in QGIS

I have my custom CRS in table "spatial_ref_sys" in database. When I load layer from schema "public", QGIS create this CRS. But if layer from other schema, it's not. What I need to solve this problem?
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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 ...
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Sphere rendering inside out using QGIS on Ubuntu?

I'm trying to use QGIS to show earthquakes around a 3d globe. I changed my CRS to 'Sphere_Van_der_Grinten_I' and it rendered like this: Here's a report from Hardinfo on my system and display: ...
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QGIS: CRS, ellipsoids and area calculation

I have a doubt about dynamic CRS, ellipsoids and area calculations. I am using QGIS 2.14.0 (still waiting for IT to install 2.14.11...) When I load a polygon table into a new, empty project, it comes ...
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Can gdal be used to generate a single patch of the HEALPix projection?

Given a geo-referenced map of the world, I am able to produce a version with a HEALPix projection using gdalwarp like this: gdalwarp -t_srs '+proj=healpix +a=1 +ellps=WGS84 +wktext' -te -3.14159265 -...
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Converting lat/long to EPSG:3857 coordinates

The map widget I'm using gives me click locations in lat/long. I need to convert those coordinates to EPSG:3857 to query a database. Most of the solutions I've found use the formula described in ...
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Creating Proj4 string for local coordinates

I am fairly new to coordinate system conversion, so am rather lost on the following problem. We have been using Proj4 to convert between various coordinate systems which is fine for known coordinate ...
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Crop raster based on another raster R

library(raster) How can one clip one raster based on another raster? RasA: class : RasterLayer dimensions : 459, 533, 244647 (nrow, ncol, ncell) resolution : 10000, 10000 (x, y) extent ...
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Creating custom CRS based on local project parameters in QGIS?

I'm having trouble creating custom proj4 CRS files to work with existing .shp files on local project coordinates. (Local in that the coordinates are relative only to themselves and not the 'real world'...
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Why does field calculator compute area in square meters?

I am using EPSG:102748, and have set my Settings/Option preferred measurement units to ft. My CRS is NAD_1983_StatePlane_Washington_North_FIPS_4601_Feet, and when I use the measure tool, it returns ...
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Is there a way to expose Spherical Mercator Lat Lon in Google Map API?

The map tiles in the Google Maps are in Spherical Mercator projection (srid 900913), but in the API the methods report coordinates in Lat/Lon WGS84, e.g. map.getCenter(). Is there a way to return the ...
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Convert land-based camera image pixel x,y to ground lat/long or x,y,z

I have a number of cameras at various known locations (x,y,z) and directions that are above ground about 20 feet pointed at different ground locations about 100 feet away from each camera, and whose ...
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Fortifying re-projected shapefile for ggplot2 in R

I have a shapefile of US county boundaries which I got from the NHGIS. I can load the file using the rgdal package and see information about it: library(rgdal) shp_1860 <- readOGR("shp", "...
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Reprojecting raster data from a rotated pole grid

I have some raster data (ASCII grid files) that use a custom rotated-pole projection, that I'd like to reproject into something more useful, such as lon/lat WGS84. A description of the grid projection ...
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3D projected map: put locator from GPS coordinates

Hello I'm a newbie in maps and not so good (as I wish to be...) in math and geometrics stuffs. So: I have a 2d google map. I have to put a 2d projection of this map (not exactly this one but a ...
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Geoserver does not wrap GRIB raster points to coordinates where x < 0

I am new to the GeoServer and want to use it for plotting wind barbs based on a GRIB file over land data. The wind barbs are properly created but nothing is shown on coordinates x < 0. The map ...
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Recreate a Local Custom Coordinate System from Survey Data in GIS?

I have a .DWG file of a series of survey points that has no associated projection file with it. The surveying group I received the data from states that the system they use is a local coordinate ...
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Calculating the geographical distance between two points (especially Gnomonic)

I tried to get geographical distance between two points by using spherical trigonometry, Mercator and Gnomonic projection. The detail of 2 points point A ( 15º 55’ S, 5º 44’ W) , B( 32º 19’ N, 64º ...
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QGIS Transforming from ETRS89 to WGS84 - why are Helmert parameters 0?

If ETRS89 (EPSG:4258) is tectonically fixed and WGS84 (EPSG:4326) isn't, the Helmert coefficients shouldn't be zero, right? In fact these parameters should diverge more and more with every new release ...
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Georeference an unreferenced image using rasterio in Python

I have unregistered/unreferenced 6 band TIFF images that I have been trying to export as georeferenced GeoTIFFs. The GPS coordinates of the corners of each image is known and each image is 1024 height ...
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EPSG:4326 being saved as CRS:84

I am trying to save a GeoJSON file in QGIS as EPSG:4326, but it keeps being saved as CRS84. EPSG:4326 and CRS84 are the same except CRS84 saves coordinates as long, lat - and EPSG:4326 saves them as ...
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Proj.NET transform wkt to lat lon coordinate list

I am looking to transform from a WKT in 27700 into lat lon list of coordinates, but cannot quite work out how to do it using this library: https://archive.codeplex.com/?p=projnet I can easily do a ...
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Intersection and area calculations in geographic vs. projected coordinates

I think one should do intersection calculations when layers are in the same coordinate system, and one should do area calculations in the appropriate projected coordinate system. The order matters, ...
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Finding correct CRS using QGIS?

I have a GeoTIFF layer (downloaded from US Dept of Interior) that is US population density. The metadata claims it is in EPSG:4267, which isn't even intended for use in that part of the world. (east ...
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1answer
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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 ...
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1answer
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Changing Leaflet Projection?

I am new to leaflet. I am trying to change Leaflet project to EPSG:32624 but it is not working. The map is not showing neither the marker. var crs = new L.Proj.CRS('EPSG:32634', '+proj=utm +...
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How to add Projection name, Ellipsoid, and Datum in QGIS 3 layouts

I am trying to add the map CRS information to text boxes in a layout in QGIS 3 automatically so if the project crs changes the text in the map will also change. I can add the EPSG code to a text ...
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Georeferencing image in QGIS?

I have a problem with projection. When I try to georeference an image in QGIS, I set up CRS WGS 84 Pseudo Mercator (EPSG: 3857). That info appears in georeference settings and it is also my default ...
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create custom SRID from OGCWKT

I wanted to create a new SRID for use in PostGIS. My goal is to have a SRS that can cover an entire state (instead of have multiple zones as in SPCS). For example, I wanted to create a new SRS for ...
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Export/Import CRS for use on similar/same file?

I have a slightly strange request. I have access to a set of geo-ref'd PDFs that have multiple layers within the file. As touched on in other threads, there's no good way (at this time) to turn on/off ...
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Import projection from existing layer

I work with many different projections and often times find my self working with a projection I do not recognize. For example, I often times will get a generated CRS I do not recognize (* ...
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Scaling two rasters to same elevation scale in QGIS?

I'm pretty new to using GIS, but I've got two overlapping rasters of the same general area - one's a 1m resolution DEM from the Pennsylvania side, and the other's a 0.6m DEM resolution from the ...
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Determining map-projected coordinates in custom CRS for Leaflet?

I have some static USA maps in Lambert Conformal projection that I would like to overlay in Leaflet together with geo-reference support. They are centered at 38N, 98W. I have found that the closest ...
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Calculate lat/long as percentage distance between two points (MSSQL)

I've loaded the US road shapes into MSSQL. I've determined the query to locate the segment of road for a specific address. The segment contains a "linestring" from a series of points. I'm trying to ...