Questions tagged [epsg]

A group that maintains a freely available database with standard codes for coordinate systems, datums, spheroids, units and the like

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120
votes
3answers
125k views

Difference between WGS84 and EPSG:4326?

What is the difference between WGS84 and EPSG 4326? It seems like for a given dataset it might be both WGS84 and EPSG:4326.
45
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2answers
40k views

What's the difference between EPSG:4326 and EPSG:900913?

I am a bit confused on EPSG:4326 and EPSG:900913. I thought that they were both same. Though as I am placing my features over GMaps, which is EPSG:4326, I need to define the srsname of the WFS layer ...
44
votes
3answers
17k views

What is the current Web Mercator projection code?

The web mercator projection, popularised by Google Maps, seems to be given a new EPSG code every couple of years. EPSG:900913 (Google in calculator text) was an unofficial code EPSG:3785 - is the ...
40
votes
2answers
29k views

What is the difference between EPSG:900913 and EPSG:3857?

I'm using the QGIS google layers plugin to digitize a parcel as a shapefile. Later I want to import it to PostGIS. I know that google maps use a special 'google mercator' projection. What is the ...
22
votes
3answers
5k views

Do ArcGIS SpatialReference object factory codes correspond with EPSG numbers?

I've got a project where I'm reading in geometry objects from text files to put them in ArcSDE. These geometry objects have an associated EPSG code, and I'm looking for a way to ensure they're in the ...
17
votes
2answers
4k views

Reprojecting WGS 1984 Web Mercator (EPSG:3857) in Python with GDAL

I am reprojecting rasters in python using GDAL. I need to project several tiffs from geographic WGS 84 coordinates to WGS 1984 Web Mercator (Auxiliary Sphere), in order to use them later in Openlayers ...
16
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1answer
4k views

Using customized Coordinate System in ArcGIS Desktop?

I don't know so much about coordinate systems... In my office we use to deal with spatial data coming from archaeological sites. Each site has its own x-y-z coordinate system (GCS). Three simple ...
16
votes
3answers
12k views

How to georeference a web mercator tile correctly using gdal?

As an example I will take the following tile http://a.tile.openstreetmap.org/3/4/2.png and save it as "4_2.png". The WGS84 coordinates of this tile can be calculated or read there by clicking the ...
15
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3answers
78k views

Changing projection of shapefile in QGIS?

How do I change the projection of my shapefile using QGIS? The default projection is set to EPSG:3003, I want to change it to wgs84 EPSG:32632. When I do a reprojection or I change projection in the ...
14
votes
1answer
478 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. ...
13
votes
3answers
43k views

Change OpenLayers 3 view center

I'm using OpenLayers 3 to interact with some maps. I first declare my map: map = new ol.Map({ target: 'map', layers: [ new ol.layer.Tile({ ...
12
votes
2answers
694 views

What's the meaning of numbers before an EPSG code, e.g. the 6.9 in EPSG:6.9:4326?

A WFS server I was using offered boundaries data in the following EPSG codes: EPSG:6.9:27700 EPSG:6.9:4326 ...defined in the XML giveCapabilities spec like this: <DefaultCRS>urn:ogc:def:crs:...
10
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2answers
3k views

How can I convert geomagnetic coordinates to geographic coordinates without doing the math myself?

I have some data which are in geomagnetic coordinates; that is, they are latitude and longitude, but in reference to the magnetic north pole in Canada rather than the geographic north pole. As you ...
9
votes
1answer
548 views

Why isn't QGIS detecting CRS from .prj file?

I have a number of 1 km hexagonal grids that cover various counties in the United States in a postgreSQL/postGIS database. Each grid has the CRS EPSG:3857, and the counties layer has EPSG:3857. When ...
8
votes
2answers
1k views

What is the difference between spatialreference.org catalogs: EPSG, ESRI, and User-defined?

I'm trying to understand EPSG codes. I've been to the spatialreference.org site, and in its "about" link, it states: "There are currently three distinct catalogs of spatial reference systems on this ...
7
votes
2answers
7k views

How can EPSG:3857 be in meters?

It is said that unit of measure for EPSG:3857 is the metre. How it can be, if the range of these coordinates is Projected bounds: -20,026,376.39 -20,048,966.10 20,026,376.39 20,048,966.10 (from the ...
7
votes
2answers
1k views

Is there a standard vertical datum for meters below the WGS84 ellipsoid, or below MSL?

I have data I am publishing a WMS layer representing data under the surface of the water, say temperature at 100m depth. What is the accepted way to represent this in WMS GetCapabilities document? ...
7
votes
1answer
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]],...
7
votes
1answer
1k views

How to choose the EPSG projection?

Up until now for reprojection of my WGS84 vector (.shp) and raster files (.tif), I have been using EPSG projections based on vector/raster central point's UTM zone. But what happens if the envelope-...
6
votes
3answers
4k views

Extracting EPSG from a raster using gdal bindings in Python [duplicate]

My goal is to check that a shapefile and raster have the same projection and datum using EPSG number. One can easily extract EPSG number from a shapefile by the following: ds=ogr.Open(r'.......
6
votes
2answers
1k views

What is the SRID for EPSG 102743?

I am trying to create a table in PostGIS for some LiDAR data and I need to set the the_geom column to my data's SRID. My data is in EPSG 102743, but when I try to use 102743 as my SRID as the_geom I ...
6
votes
1answer
2k 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?
6
votes
2answers
4k views

Converting EPSG:2284 to EPSG:4326 with pyproj

I have some points in EPSG:2284 and I'm trying to convert them to EPSG:4326 using pyproj, however I get weird results. When I go to the spatial reference website I see that there is an endpoint that ...
6
votes
1answer
662 views

How to fix distortions in rendered OpenStreetMap maps?

I use OpenStreetMap in order to generate maps and add some cool stuff in it. Actually I have good results but I seem to have a problem with reporting a good image ratio when I create my generated file....
6
votes
1answer
1k views

How to find the actual projection name (code) in a PROJCS text data?

Given a PROJCS data PROJCS["unnamed", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223560493, AUTHORITY["EPSG","7030"]], ...
6
votes
1answer
2k views

how to add a custom SRID to Spatialite

I'd like to create a spatialite database and load it with shapefiles using the Mississippi Transverse Mercator (MSTM) projection, but it doesn't have an EPSG definition in the spatialite library of ...
6
votes
1answer
4k views

Distances in {Plate Carrée projection - EPSG:4326 - WGS84}

"4326 is just the EPSG identifier of WGS84" [3] Indeed http://spatialreference.org/ref/epsg/4326/html/ says it is a GEOGraphic Coordinate System: GEOGCS["WGS 84", DATUM["WGS_1984", ...
6
votes
1answer
1k views

How do I change an existing srs in QGis?

I am showing postgis data with srid 28992 (Amersfoort / RD New). But when I plot the geospatial data on a map (with openlayers plugin), the data is shown a hunderd meters off because the datum shift ...
5
votes
2answers
5k views

What is the proj4string of the Lambert azimuthal equal-area projection?

Shapefiles of European data are available on the Eurostat website. I have loaded the NUTS_2013_60M_SH Shapefile in R with the command; europeRG <- readOGR(dsn = patheurope, layer = "...
5
votes
1answer
6k 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 ...
5
votes
1answer
1k views

PostGIS spatial reference ID (SRID) for regular cartesian coordinate system?

I would like to store a polygon as a set of 2D points represented as x, y coordinates of a Cartesian coordinate system. Which spatial reference can I use? Looking at my spatial_ref_sys table, all the ...
5
votes
1answer
811 views

Convert Lat/Lon sexagesimal degrees to UTM coordinates

I'm using proj4.js to convert geographic coordinates (degrees, minutes and seconds) to UTM coordinates (ETRS89 Zone 30). When I get my coordinates result of the transformation I'm checking them with ...
5
votes
1answer
540 views

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 ...
4
votes
1answer
10k views

Using Fiona to write a new shapefile from scratch

I am new to Fiona, and trying to wrap my head around reading a csv file and writing out an ESRI shapefile. I have most of it down, but am missing two things; (1) defining the projection/spatial ...
4
votes
3answers
319 views

How to find the extent of (many) EPSG CRSes?

I want to map the geographic extents / bounding boxes of a lot of EPSG CRSes. At least, those with a rectangular geographic extent. For example, take epsg:2004, visiting that page shows the extent (...
4
votes
1answer
226 views

Reproject shapefile in QGIS using “save as” return weird result

I need to reproject a shapefile from a geographic cooridante system (ESPG: 4326) to a projected coordinate system (EPSG: 54004). Obviously something went wrong but I'm not sure what.
4
votes
1answer
4k views

leaflet map crs is 3857 but coordinates 4326

I am developing my first leaflet applications. So this is my trial application demo. var osmUrl = 'http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', osm = L.tileLayer(osmUrl, { ...
4
votes
1answer
223 views

Why ogr doesn't read this kind of prj

I run the code below, that I would hope to return the parameters from projection file (.prj). However it doesn't work as I would expected. I realized that the it isn't working because the some ...
4
votes
1answer
114 views

Analyze the extent of a NTv2 grid

I am using a NTv2-grid for transformation of geodata. The grid can be found here: gsb-file: https://www.lgl-bw.de/lgl-internet/web/sites/default/de/05_Geoinformation/Galerien/Dokumente/BWTA2017.zip ...
4
votes
2answers
314 views

What is the epsg code of eurostat maps?

Shape files of Europe maps are available on the Eurostat website. I downloaded NUTS_2013_60M_SH. The tool (readOGR from the R package Rgdal) I use to load the map shows the following proj4string: "+...
4
votes
1answer
3k views

Using Cassini-Soldner projection in QGIS?

I have a shapefile in a Cassini Soldner reference system centered in Monte Mario (Italian cadastre map). I want to insert these data inside QGIS in order to compare data with aerial images. When ...
4
votes
4answers
4k views

Proper gdaltransform syntax to transform a list of coordinates?

this is probably a very simple question, but I'm very new to GIS so I just need one last nudge. I've got a sense of the Linux utility gdaltransform and I am feeding it coordinate pairs in line-by-...
4
votes
2answers
119 views

Get a list of all supported EPSG code from OGR

I need get a a list of all supported EPSG code from OGR/GDAL. I need this becaouse i'm developing a C++ application map, and I need this information to put it in a user form. I read the OGR ...
4
votes
1answer
1k views

Google Earth Engine Reprojection to non-EPSG defined CRS

Is it possible to reproject an image in earth engine to non-EPSG defined coordinates? In particular either Goode Homosline (SR-ORG:7619) or Mollweide (ESRI:54009). Passing either to .reproject() ...
4
votes
1answer
723 views

Converting EPSG to D3.js

Given an EPSG projection (say, this Alabama one: http://spatialreference.org/ref/epsg/26729/) How can you take the given WGS84 projection bounds in such a way that you can use them in a D3.js ...
4
votes
1answer
3k views

Converting UTM to Lat/Long with a geoJSON file in pyproj

I am trying to convert a geoJSON file in UTM (EPSG 29902) to WGS84. I've seen other examples online which show how to use the transform function in pyproj; however all the ones I have seen are for a ...
4
votes
1answer
1k views

How to convert gml:pos to latitude and longitude?

I'm trying to figure out the latitude and longitude of rail stations that are contained in this WMS feature list. I'm completely new to the GIS field, so please forgive me if I use the wrong terms ...
4
votes
1answer
204 views

Differences in the longitude and latitude between a LiDAR DSM and an optical image

I've downloaded the UK's LiDAR elevation data (see below) in laz format for a specific region (Tewkesbury) from: http://environment.data.gov.uk/ds/survey#/download From that, a DSM (Digital Surface ...
4
votes
1answer
4k views

Is there an EPSG code to specify WGS84 in (lon,lat) order instead of (lat,lon)?

Is there an EPSG code like EPSG:4326 or EPSG:4329, but that specifies (lon,lat) order instead of (lat,lon)? I've tried exploring the websites http://spatialreference.org and http://epsg-registry....
4
votes
2answers
1k views

Adding custom projection to epsg.properties?

I have created an entry at www.spatialreference.org of a customized .prj file. http://www.spatialreference.org/ref/sr-org/7973/ I'm trying to add the generated geoserver entry to the EPSG.Properties ...