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.

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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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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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515 views

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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1answer
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Can GDAL Perform Vertical Transformations?

Can GDAL perform vertical transformations? If the answer is yes, please indicate which amongst these listed pages can explain how exactly to accomplish vertical transformations? If there is some ...
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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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115 views

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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234 views

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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118 views

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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280 views

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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195 views

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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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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934 views

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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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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847 views

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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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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631 views

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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851 views

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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1answer
66 views

Handling projections with QGIS?

I know this may sound like a silly question, and it is, but I've read lots of questions and tutorials, watched a few videos and still can't properly understand what I should do... I am trying to work ...
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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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116 views

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
415 views

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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113 views

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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115 views

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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249 views

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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Different coordinate systems match in QGIS but not in ArcGIS

I have digitized some shapefiles (polygons) in QGIS. Some polygons have the CRS 5678 DHDN 3-Degree Gauss Kruger Zone 4 E-N and the rest have the CRS 4326 WGS84. The Project coordinate system is also ...
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1answer
397 views

How to get square metric pixels for a GeoTiff, whose pixel spacing is given in degree?

I have received a GeoTiff file, whose pixel spacing is provided in degree (e.g. +1° to the right, -1° down). Of course, this means that the actual, metric pixel spacing changes in relation to the ...
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484 views

How to get pixel coordinates in QGIS georeferenced output map?

using the QGIS Georeferencer GDAL plugin, I can select GCPs (ground control points) on a map (plain raster input map image in a format like PNG or TIF) in an unknown projection and boundaries, and ...
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39 views

Conic projection view transformation

I am building a custom map viewer, part of meteorological production system, using Java language and GeoTools library. I have prepared a custom map renderer, using OpenGL, that allows to display maps ...
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Can't get georeferenced Autocad DXF to right coordinates

I am not a frequent Autocad user. I wanted to export some floorplans from Autocad 2016 DWG to a final GeoJSON file to be loaded in a Google maps JS app. My steps are: 1)in Autocad set a location ...
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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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How to reproject a latlong J2000 coordinate image into latlong Galactic Coordinate image

I have a 2x1 ratio lat/long projection of the night sky in J2000 equatorial coordinates (the fixed equatorial coordinate system on Jan 1.5, 2000). I need to convert this into a 2x1 ratio lat/long ...
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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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QGIS 3D Globe Plugin Elevation Map Projection

I'm trying to get a map setup using the QGIS 'Globe Plugin'. I've been trying to use the UK Environment Agency LIDAR data as an elevation map. After a bit of puzzling this out I've found that the ...
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510 views

Aligning layers in QGIS?

I am new at QGIS and am having a problem aligning layers. Possibly I just don't understand how projection works. I have two layers: GPS waypoints collected in a GPS UTM zone 55N Polygon shapefile ...
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569 views

Converting KML coordinates to Leaflet

I am trying to convert a Google Map KML file to a csv, to map the longitude and latitude points on Leaflet. But the coordinates keep mis-projecting and some end up off the land mass. The steps I have ...
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121 views

Rectangle shapefiles with the same extents does not align perfectly after projection

I have a rectangle shapefile built with UTM19 coordinates using a python script, and then projected to NAD83_CSRS (EPSG:4617). I have a second rectangle shapefile built with the same method (python ...
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188 views

Wrong area using Albers Equal Area Projection in GRASS for Java, Indonesia

I am just getting to know GRASS 7.0 and I am struggling finding a good projection to work on a spatial analysis of Java, Indonesia. I am new to the forum, so if information's are missing for a better ...
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725 views

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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202 views

Regridding vector values

I'm trying to regrid and interpolate vector values from WAM model output. I got WAM model netCDF output in rotated grid, I need to interpolate it to another grid which is some variant of LAEA ...