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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Converting point to lat lon? [duplicate]
I have received a shapefile with measurement points to be analyzed, but no matter how I try, I can't find how to convert to lat lon. I suppose it would be good to know the projection but when I look ...
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Real-world example of Affine Transform?
From the Wikipedia article:
In geometry, an affine transformation or affine map or an affinity (from the Latin, affinis, "connected with") between two vector spaces (strictly speaking, two affine ...
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SRID and Name relationship
PostGIS comes with a table of spatial reference systems with each one being identitfied by a SRID. However, from a user's perspective, SRID is just a number and doesn't tell them much. Is there a ...
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Reprojecting layer using PyQGIS
I'm trying to find a very simple solution to reproject a vector layer into a temporary layer in PyQGIS, however documentation is really extensive and I'm fairly new to PyQGIS; the only answer I've ...
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What does the default crs being EPSG:3857 in Leaflet mean?
In the documentation of leaflet, it says the following about the projection that is being used:
L.CRS.EPSG3857 The most common CRS for online maps, used by almost
all free and commercial tile ...
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Specifying CRS of raster layer using PyQGIS
I am manipulating NetCDF raster data from the QGIS Python Console. The metadata of my NetCDF file does not provide the Reference system. However, I know it is 'EPSG:4326'.
I am writing a Python script ...
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ogr2ogr srs options: where is the well known definition determined?
In the ogr2ogr documentation it says that when using -a_srs srs_def:
Srs_def can be a full WKT definition (hard to escape properly), or a well known definition (ie. EPSG:4326) or a file with a WKT ...
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Is SRID 4326 Lon/Lat or Lat/Lon?
I built a wep app storing GPS coordinates, as SRID 4326. Coordinates are stored as Lon/Lat, and that was working fine on MySQL 5.6 and MySQL 5.7.
Since I upgraded to MySQL 8, I get the following error ...
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When to enable 'On the fly' CRS transformation in QGIS? When to turn it off?
I understand what 'On the fly' does, and I have re-read https://docs.qgis.org/2.6/en/docs/training_manual/vector_analysis/reproject_transform.html
I tend to have it turned on all the time, but I don'...
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World map projection with United States in center
I am creating a map showing flight paths originating in the United States and traveling to Asia and Europe. I need a projection for the world that will focus the United States in the center of the map,...
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Clipping polygons to hemisphere for azimuthal orthographic projection using QGIS
I'm a bit of a novice with QGIS, so this is really throwing me for a loop.
For the maps I'm intending on making, an azimuthal orthographic projection would be my preference.
For example, one map I'...
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Lat/Lon/Alt to spherical or cartesian coordinates
On my previous question, it was advised I convert lat/lon/altitude to spherical or Cartesian coordinates. I'm not working near the poles and it would be safe to assume a spherical earth. What would be ...
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What Spatial Reference System do I store Google Map's Lat/Lng in
I am new to PostGIS, Spatial Reference Systems and projections and want to store lat/lng coordinates retrieved from Google Maps and Openstreetmap and its services like the Geocoder/Nominatim. I'm ...
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Is the quadrilateralized spherical cube map projection the same as Snyder's cubic equal area map projection?
Is the quadrilateralized spherical cube map projection [1] the same as Snyder's cubic equal area map projection [2]?
I know both are equal area polyhedral map projections ( http://www.progonos.com/...
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Equal Area SRID for Australia
Does anyone know the SRID for an equal area projection that is suitable for the whole of Australia?
I realize that I could make my own (which I have done) but I am looking for one that is present ...
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Using grid files (*.gsb) in QGIS
When opening a data source in EPSG:25832 in a project with crs set to EPSG:31468 I am prompted to select a datum transformation (e.g. +nadgrids=BETA2007.gsb)
The nationwide standardized grid file for ...
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Distance measurements across UTM zones: use geographic or planar approaches?
I have a survey grid spread across 3 UTM zones (36N, 36S, 37S). I want to find the nearest (or shortest) distances of the centroids of these grids to roads and various points between.
It seems like ...
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Re-projecting raster in R: gives warning that projected point(s) not finite?
1. Question
I have encountered a warning using the projectRaster() function in the raster package in R. A full reproducible example is pasted below.
Warning message:
In rgdal::rawTransform(...
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What is my coordinate system preserving?
I'm trying to get a better grasp of coordinate systems, datums, projections etc. I understand that certain systems preserve different things; distance, shape, angles, area. I'm wondering how you can ...
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gdal_translate or gdalwarp to define projection
Which of these is the best approach to define (AKA. set) a projection for a tiff?
1) gdal_translate -a_srs EPSG:32182 in.tif out.tif
2) gdalwarp -s_srs EPSG:32182 -t_srs EPSG:32182 in.tif out.tif
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Why are heatmaps on qgis 2.8.1 produced in the wrong CRS?
I noticed that the heatmap calculation on the new upgrade version of qgis is given the raster map without any coordinate system.
Have you got the same problem?
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Convert coordinates from readShapePoly in R to long-lat coordinates
I'm trying to find some centroids of a shapefile for Danish municipalities and afterwards find the driving time between them. I use R's readShapePoly function from maptools combined with the ...
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Using ArcMap, how may I convert a shapefile to use decimal degrees?
I have a shapefile that currently uses meters as the measure for its coordinate system, but the map framework I wish to use expects decimal degrees. I'd like to reproject my shapefile to use decimal ...
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ValueError: Cannot transform naive geometries
I was trying to execute this code:
# Load geojson files
country = gpd.read_file('svn_buffered.geojson')
train_shp = "large_training_aoi.geojson"
test_shp = "large_test_aoi.shp"
train_polyg = gpd....
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Adding CRS to shapefile in GeoPandas
I am trying to add CRS to a shapefile that I am exporting:
shp1 = gpd.read_file(i[1], encoding='iso8859_7', crs_wkt='2100')
shp1.to_file(out, encoding='iso8859_7', crs_wkt='2100')
When I import it to ...
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Choosing UTM zone to use for large country?
I want to reproject OpenStreetMap roads data from the current projection (WGS 84) to UTM, since I read in another GIS SE Q&A(Getting $length in meters in QGIS?) that WGS 84 cannot be used to ...
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Getting units from ISpatialReference of ArcObjects?
How do I get the units (meter/feet) from an ISpatialReference object in ArcObjects?
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Order of latitude and longitude in EPSG:4326
I recently started working with GPS data in PostGIS and am very confused about the order of latitude and longitude. I'm from Europe, and here everyone I know uses latitude first, longitude second, e.g....
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Why Google Maps no longer disable Mercator's projection on zoom out
Back in 2018, Google Maps start to get rid of mercator's projection in maximum zoom-out
So we can see the size of island (moreover those in poles) in it's original sizes
But today I try both in PC and ...
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Convert an arbitrary meta-data-free map image into QGIS project
My background: experienced programmer, amateur historian, complete beginner to GIS (so I'm using QGIS). I did learn to use the QGIS georeferencer tool though.
The input: suppose I have an image like ...
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Why are there both square and rectangle world maps?
When i search for images of earth divides to longitude ans latitudes seems that the are 2 major types:
is a perfect square and the latitudes in it are grow a different rate from the equator to up ...
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Geopandas vs QGIS vs ArcGIS area values
I'm calculating areas of a KML in QGIS, ArcGIS and GeoPandas and all of then are different, my results are this:
Geopandas
ArcGIS
QGIS
29.3498
28.500084
25,651554
The original crs of the KML is ...
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Sentinel-2 projection shift
I recently observe a shift in the geographic projection of Sentinel 2 data. Please see the screenshots below for clarification (Granule T33UXP, Band 8 only). The first image was taken on 20160314, the ...
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Why recommended transformation is not the most accurate in QGIS?
When I am prompted for a transformation to use in QGIS, the recommended/default option (in green) is the least accurate one. In my case, QGIS recommends a transformation with an accuracy of 6m when ...
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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 ...
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Georeferencing LAS files in geographic coordinates (lat/lon) or in cartesian (projected) ones?
First of all, I am a newbie in GIS.
I have a lidar point cloud with GPS and telemetry data associated. Then, I transform coordinates of every point to an ECEF coordinate system and finally I ...
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Understanding GeoTIFF tags?
I'm trying to understand GeoTIFF info, but not getting far. For instance, using listgeo with one file I can get this output:
Geotiff_Information:
Version: 1
Key_Revision: 1.0
Tagged_Information:...
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An example Tissot ellipse for an Equirectangular Projection?
I am trying to calculate distortion of an equirectangular projection via Tissot indicatrices. I have tried following the directions on this post (among other things) but it is beyond my understanding ...
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Is the GEO tag for QR codes lat/long or long/lat
I just found out that you can add a geographic component to a QR code.
I also just found you can create one on the Google Chart API using this:
https://chart.googleapis.com/chart?cht=qr&chs=...
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Bertin 1953 map projection settings
I am trying to use the Bertin 1953 map projection, as described in the book "Semiology of graphics" by Jacques Bertin. But I can't find the settings in any of my GIS software.
Does anybody ...
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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 ...
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Using base layer of two different projections (Spherical Mercator and WGS84) in OpenLayers
How do I add baselayer with two different projections?
I have added overlayer with a different projection(EPSG:4326), but I need to add base layer with various projection
Google Maps
My vector ...
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Printable Globe in QGIS
I'm trying to figure out how to use QGIS to print a map so that it can be wrapped around a sphere. I haven't found a projection that will display the map in a way similar to these.
It sounds like ...
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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:102654'), 5280)
However, the ...
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Nearest point on a line ( Spherical / Mercator projection )
I have a line (Ax,Ay - Bx,By) over a mercator projection (google maps) and a random point (Cx,Cy) nearest to that line, i would to know the closest point (transparent blue on the image) over that line ...
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QGIS 3.0.0. Coordinate display incorrect
My CRS is reported by QGIS (project properties) as being ED50/UTM31N (EPSG 23031) and that seems to be correct as all layers are positioned correctly. However, the coordinate display box shows the ...
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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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Mercator bias plot in Leaflet
I was inspired by this wikipedia image from the mercator projections page to hack around with leaflet. The idea was to interactively have your cursor move a continent and that it would be corrected ...
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How do ESRI and QGIS calculate scale values of geographic projections? [closed]
Does anyone know how (from which location) scale values are calculated in ESRI products and QGIS for geographic projections?
The only thing I've noticed is that QGIS is changing scales when you pan ...
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Convert 3D WKT to 2D Shapely Geometry
I have the WKT of many linestrings which contains three dimensions, however my script only requires a two dimensional linestring and I therefore want to discard the third dimension.
My current code, ...
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