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

learn more… | top users | synonyms

37
votes
3answers
13k 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 ...
35
votes
3answers
32k views

What is the difference between WGS84 and EPSG4326?

What is the difference between WGS 84 and EPSG 4326? It seems like for a given dataset it might be both WGS 84 and EPSG 4326.
26
votes
2answers
19k 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 ...
16
votes
3answers
3k 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 ...
15
votes
2answers
11k 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 ...
13
votes
3answers
8k 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 ...
10
votes
2answers
2k 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
591 views

Using customized Coordinate System for Archaeological site data

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 ...
7
votes
2answers
667 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? ...
6
votes
1answer
323 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
1answer
286 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 ...
5
votes
0answers
898 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 ...
4
votes
2answers
5k 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({ ...
4
votes
1answer
464 views

EPSG operations and operation methods

Querying through the EPSG database, I can see the tables epsg_coordoperation where transforms and conversions between different CRS are stored, and epsg_coordoperationmethod which stores the ...
4
votes
1answer
442 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 ...
4
votes
1answer
947 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 ...
4
votes
1answer
2k views

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

So, "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", ...
4
votes
0answers
192 views

GeoJSON shape distorted on Leaflet.js spherical mercator WMS map [closed]

I have a map with a simple WMS layer in spherical mercator projection (rendered by a OSM-Mapnik-TileCache server stack, everything is in EPSG:900913 / EPSG:3857). First: I can't understand why, if ...
3
votes
1answer
146 views

Problem with projection in layer

I'm having problems with visualizing a layer which is in EPSG:4326 Apparently the geometry looks perfect, but I don't know why, it's not in real coordinates. I have projected it to 4326 with QGIS, ...
3
votes
1answer
1k 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: ...
3
votes
2answers
635 views

Error transforming EPSG:4326 to EPSG:90013

When I'm trying to run a map on geomajas an error has occurred: o.g.internal.service.GeoServiceImpl - Problem during transformation EPSG:4326->EPSG:900913 of MULTIPOLYGON The multipolygon ...
3
votes
2answers
297 views

How do I automatically export a release of the EPSG registry?

I am trying to use the EPSG Registry API to export a release of the registry for offline use but am receiving a registry error. After following the Developer Guide I am HTTP POSTing the following XML ...
3
votes
2answers
81 views

EPSG:3575 projected bounds

I've been trying to find out what the projected bounds are for EPSG:3575 but have not been able to find a definitive answer. Normally, I'd just use the values from EPSG.io but when I tried these in ...
3
votes
1answer
98 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 ...
3
votes
1answer
88 views

Misalignment of EPSG:4326 and EPSG:3399 coordinates

I'm having a QGIS project in local coordinates (Gauss-Kruger, EPSG:3399) with some layers in the same reference system. On top of that, I want to display point coordinates, which I digitized using ...
3
votes
1answer
186 views

Convert planar distance to ellipsoid (real) distance

I have the following linestring which approximately marks an airport runway: LINESTRING(-381578.819887 6574044.360475, -378513.534443 6574799.475787) # EPSG 3857 LINESTRING(-3.427781 50.732117, ...
3
votes
1answer
294 views

Is there no EPSG code to use for Behrmann equal-area projection in ogr2ogr?

I'm trying to use ogr2ogr to reproject some shapefiles. The projection I wish to use is Behrmann equal-area. I cannot find an EPSG code to use for the '-t_srs' part of the syntax. Is there any way ...
3
votes
1answer
75 views

Local Ortho projection to Proj4

We are trying to use proj4 to project a local coordinate system to EPSG4326. We believe we have most of the string created correctly in QGIS and as follows; +proj=ortho +datum=WGS84 ...
3
votes
1answer
64 views

How to define custom projection EPSG:5714 in QGIS

I have a series of raster files with the CRS EPSG:5714. I need to define this CRS in QGIS but I'm fairly new to this and have no idea how to define the proj4 CRS for this. I searched at ...
3
votes
1answer
617 views

How to convert a geotiff from WGS84 to 3857 with gdalwarp?

I'm trying to convert images with WGS84 projection to 3857 but warp is not giving me a output I would expect. This is my command: gdalwarp -s_srs "+proj=merc +datum=WGS84" -t_srs "EPSG:3857" ...
3
votes
1answer
81 views

Why does projection WKT differ between osr.SpatialReference and gdalinfo

I am writing a simple geotiff using the GDAL python bindings, but the projection WKT reported by gdalinfo differs from the source. The script from osgeo import gdal, osr import numpy # Create ...
3
votes
2answers
480 views

How to make QGIS recognize EPSG:31468?

I have Shapefiles without a CRS (e.g. without .prj file). I would like to set the CRS (EPSG:31468) before I pass the Shapefiles. I tried the following: Setting a .prj file manually with the string ...
3
votes
0answers
600 views

How to set GDAL/cs2cs/proj to use NTv2 grid shift file when using EPSG codes?

I am using the GDAL API for Python for a script that takes only EPSG codes for inputs to specify source and target coordinate systems. While the cs2cs command seems to handle quite well ...
2
votes
4answers
3k views

OpenLayers transform EPSG 27700 coordinate to Google 900913

Community, I'm currelty capturing my mouse click event and trying to transform the coordinates into Long Lat. I need to get at the Long Lat as strings so I can build a url and throw it at Google ...
2
votes
2answers
304 views

Is it possible to change a Geotiffs CRS?

Hi I have created a Geotiff from the Bing Aerial photography. As it is automatically in WGS 84 it inserts perfectly into QGIS, however this image is of no use to me outside of QGIS. I need to ...
2
votes
1answer
692 views

EPSG:4326, EPSG:3857, JOSM and unprojections

It is said here that EPSG:4326 is not a projection. In my mind, a projection is a transformation of the surface of the Earth producing a flat image, notably a bitmap. We know that WGS84 (World ...
2
votes
2answers
122 views

Find unit of EPSG-Code

I need a way to find out the unit of an EPSG-Code (e.g: meter) from java (ogr, gdal, osgeo?) but any other approach would be fine as well. I want to do something like: if(epsg.unit==meter){ do ...
2
votes
2answers
305 views

How do I convert to EPSG:3857 with GDAL?

I have some TIFs in EPSG4326 the GeoTiff info looks like: GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563, AUTHORITY["EPSG","7030"]], ...
2
votes
1answer
603 views

Requesting map tiles from a wms server in epsg:900913 fails

I'm trying to figure out how to query a WMS server by using latitude/longitude coordinates. The reason is I'm trying to create an iPhone application and overlay custom tiles with data from the WMS ...
2
votes
1answer
406 views

math formula for transforming from EPSG:4326 to EPSG:3857

is there any math formula for transforming from EPSG:4326 to EPSG:3857 ? i want to implement it in php code
2
votes
1answer
227 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 ...
2
votes
1answer
447 views

How to add EPSG:5235 to QGIS?

First of all I should say I am new to EPSG and QGIS world.Then I want to Georeferced Raster image to EPSG:5235 in QGIS. But in Qgis I can't found above EPSG. How I add this EPSG to Qgis ? Pls help ...
2
votes
2answers
8k views

convert wgs84 coordinate to Google Map coordinate system(EPSG 3785) with geotools and java

Could you please point me out where can I make such a transformation: convert wgs84(EPSG 4326) coordinate to Google Map coordinate system(EPSG 3785), and vise versa. Thank you.
2
votes
1answer
58 views

WGS84 conversion to EPSG:3067

I'm trying to convert coordinates from WGS84 to EPSG:3067 with proj4js and Openlayers, but can't get the conversion right. When I run proj4('EPSG:3067',[-24.9993393, -60.184716]); it gives ...
2
votes
1answer
119 views

Which EPSG for UTM with 8 digits in QGIS

I have a UTM datasets with 8 digits, so the first digits are 32 (for UTM Zone 32N), but which EPSG should I use to get the data at the right spot in QGIS in a 6 digits system. If I want to transfer ...
2
votes
1answer
71 views

ogrinfo returns a negative coordinate for extent of mif data file

I'm trying to get the extent of a MIF file using ogrinfo. The MIF file is supposed to be in epsg:23030 projection. This is: PROJCS["ED50 / UTM zone 30N", GEOGCS["ED50", ...
2
votes
1answer
338 views

Which BC Albers should I use and is there any difference?

I was about to calculate the area of some polygons and before I did I did some research. I found that the area of the polygon will be represented in the units of the projection used. So I did some ...
2
votes
2answers
694 views

Why is Spatialite delivering “Invalid SRID” error message

Qspatialite in QGIS 1.8 (and also Spatialite-gui) delivers an "Invalid SRID" error message when I try to load shapefiles with a SRID value of 3814 (Mississippi Transverse Mercatur). The SRID is ...
2
votes
2answers
738 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 ...
2
votes
1answer
943 views

Geowebcache does not displaying map tiles in EPSG:900913 from a remote WMS server

I connect Geowebcache to a remote WMS service through their Getcapability request by adding the url in geowebcache-servlet.xml document. Geowebcache demo page displays the list of wms layers from ...