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

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36
votes
3answers
12k 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 ...
27
votes
3answers
23k 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.
20
votes
2answers
15k 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 ...
14
votes
3answers
2k 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 ...
12
votes
3answers
7k 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 ...
11
votes
2answers
8k 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 ...
10
votes
2answers
1k 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 ...
8
votes
1answer
307 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
601 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
195 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
236 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 ...
4
votes
1answer
423 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
351 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
800 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
153 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
119 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
604 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
567 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
265 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
1answer
140 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
233 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
39 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
533 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
2answers
403 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
598 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 ...
3
votes
0answers
450 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
2k 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
129 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
453 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
48 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
56 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
419 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
1answer
57 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
52 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
225 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
610 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
6k 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
896 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 ...
2
votes
1answer
161 views

how to transform DB stored EPSG data to Geography data type in sql server

I have a full, 3 GB, database in SQL Server stored with certain points stored in pure float values. The points are stored in EPSG 3765. I would prefer to have them saved in the Geograpy datatype. I ...
2
votes
1answer
183 views

Open Layers and OSGB 1936 (CRS 27700)

I've been working with loads of shapefiles projected according to OSGB 1936 (CRS 27700). THe project CRS is set to 27700 and "On the fly reprojection" to 27700 is set (I keep this as a default as I ...
2
votes
2answers
65 views

How to get EPSG with OGRinfo?

Is it possible to get the EPSG code of a shapefile with ogrinfo? I know I can get layers SRS WKT with ogrinfo -so -al stands1.shp, but I am looking for the EPSG code.
2
votes
1answer
496 views

What does 'projected bounds' and 'WGS84 bounds' mean in the definition of a CRS (on spatialreference.org)?

The site http://spatialreference.org gives 'Projected Bounds' and 'WGS84 Bounds' for each Coordinate System. What does these 'bounds' mean? e.g. for ETRS89 / UTM zone 32 N this is given: I know what ...
2
votes
1answer
266 views

How to convert NAV4 coordinate system to WGS84?

I would like to know whether it is possible to convert the coordinates given in a NAV4 coordinates system into WGS84. I could not find out what NAV4 is and if it is actually a standardized CRS. Here ...
2
votes
1answer
162 views

Is there an arcpy boolean check for whether an EPSG or prj is supported by arcmap?

I'm writing a tool and essentially I found out that arcmap defaults an epsg to 0 if it sees that the projection is not supported against the predefined projections.
2
votes
1answer
54 views

A way to transform by special epsg-code

In my country, we have a special epsg-code for transformation (#4649). In the definition ...
2
votes
1answer
52 views

Geoserver projection recognize problem

I'm publishing shape files in geoserver through curl,my problem is that geoserver didn't recognizing the projection which is in ESRI WKT format(layer was publishing).I searched for this problem i ...
2
votes
0answers
26 views

EPSG codes and water level datums

I'm curious if, and how, people use EPSG defined water level vertical datums such as Mean Low Water. There is specific guidance to not use the OGP EPSG definition: Remarks: Users are advised to ...
2
votes
0answers
172 views

Layer missing Native SRS in geoserver

I'm currently trying to get a couple of layers uploaded to a geoserver and I'm having trouble getting the projection recognized. The result of the curl command is that the two layers are both missing ...
2
votes
1answer
384 views

How do I convert EPSG:26986 coordinate pairs to EPSG:4326 from the MassGIS web service, the Linux command-line, or PHP?

I'm a GIS newbie, normally a PHP web applications developer. I am trying to map all boundaries of the MA state representative districts. So I just need to convert polygon coordinates from the ...