Hot answers tagged projection
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Load the shapefile 'as is' into QGIS and Save as KML will do the conversion and will show correctly in Google Earth.
See:
http://pvanb.wordpress.com/2012/07/31/exporting-vector-layer-as-kml-in-qgis/
for Google Maps you need to upload the kml to a public facing webserver.
Example Layer in Google Maps API v3
...
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It's true that Google uses Google Mercator (EPSG:3857 or EPSG:900913) for displaying, but I think you/the Javascript API want lat/lon coordinates for input.
So convert the data into EPSG:4326, and look if it fits.
You can load the shapefile into QGIS, and use Openlayers plugin with Google or Openstreetmap background to check if the transformation is ...
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The answer is Yes.
Have a look at this sample: Generalized Data.
If you have a look at the Original Services, the Feature service is wkid:4267, while the map and the tiled map service are in wkid:3857/102100.
If you have a look at the service call using Firebug, you will see that the data is requested in wkid 102100:
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I do not know of any automatic projection algorithm or software that could master so many challanges and unknown parameters in one picture (extremely high panorama-induced distortion in the NW direction, unknown look angle and flight height of the sensor, unequal pixel size, interrupting elements in the picture and many, many others). The only thing you ...
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Google uses Google Mercator projection. EPSG:900913. For proj4 settings see here.
To display your data in Google Mercator:
On QGIS status bar click on the grey globe icon to open the Project Properties page. Check Enable 'on the fly' CRS transformation and select Google Mercator -EPSG 900913 and click Apply.
To save data in Google Mercator:
Right click on ...
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I think, technically, this 'question' should be split into several questions! I going to try to answer your questions or clarify your statements out of order because I think it will make more sense.
A coordinate reference system, when used in the GIS field, is a generic term for a reference framework that's used to locate points (lines, polygons, etc). ...
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I'm asuming you are talking of how GIS softwares show data with Lat Long on a Flat map, like this:
Al the GIS Software that I have worked with, inlcuding ArcGIS & Qgis, treat the latlong as linear units, and show the data in pseudo Plate Carree projection.
Now that I think of it, this question seems an exact duplicate of How is EPSG:4326 data ...
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Try just setting project CRS and enabling on-the-fly reprojection. Don't touch the layer properties. If the Shapefile .prj definitions are read correctly by QGIS, that's all you need to do.
Similar questions:
Why don't my Shapefiles and OSM data overlap in Quantum GIS?
QGIS layers no longer overlay when Enable 'on the fly' CRS transformation ...
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Others have already given valid answers depending on what it is exactly you need. For whats it is worth, you could reproject both data sets to Transverse Mercator with a custom central meridian that lies directly on the mid-line between the two. Or, if you are working with data in high northerly latitudes you could simply reproject both to Lambert Conformal ...
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If you're just looking at displaying the data and since neighboring zones have some overlap (1 degree), you may consider reprojecting the zone with the least amount of data - pending there isn't too much of a spread. Note that is there is too much spread this method will introduce distortion which could affect areal calculations.
Alternatively, since your ...
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You can find a shapefile (vector) for countries as of 2010 from
http://epp.eurostat.ec.europa.eu. It think that it would be easier to change the symbology of a vector file than deal with a raster. Arcmap will project on the fly and you can set the map to a winkel projection (projected->world or world-sphere->winkel).
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A map served by Geoserver as EPSG:4326 and displayed in OpenLayers with this "projection" will look distorted. The units of measure in a EPSG:4326 is degrees, so what you are looking at are an unprojected map.
You'll want to make Geoserver reproject your WMS to eiter EPSG:900913 (or whatever EPSG-code "web/spherical mercator" has nowdays) or a local system ...
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Although I have found no documentation to the effect that a Projected Coordinate System is required it is perhaps unsurprising that a Geographic Coordinate System is unsupported because the length of a degree varies depending on the latitude.
I suspect that a documentation enhancement is the most that is likely to happen with this but I encourage you to ...
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perhaps it is (lack of) datum transformation in the projection operation? Your symptom sounds familiar. It is a common problem here in WI - GPS uses the WGS84 datum, but our state system uses NAD83HARN. The symptom of doing a projection without datum transformation is that coordinates are systematically offset a few meters in X and ~meter in Y.
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I can spot two things:
Change every instance of EPSG:900913 to EPSG:3857 -- EPSG:900913 (Or EPSG:GOOGLE if you squint hard enough) never existed in the EPSG database. It's a long story, but EPSG:3857 is the correct code.
It looks like you have one too many zeroes when you initialize your minLat and minLong variables. Compare it to your new ...
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In the end I decided to avoid the issue by making my OL layers multitiled (singleTile: false) with the appropriate maxExtent to prevent requests outside of the appropriate area. This way, since my layers are around Hawaii and never actually cross the date line, I won't have issues with OL making bad requests with respect to the IDL.
The only downside is ...
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The provider either doesn't know or doesn't wish to include a complete coordinate reference system definition in the metadata. The provider has given you the ellipsoid (spheroid) and prime meridian only. Unless you can find out somewhere else, there's no way to know what the GeoCRS and datum should be.
Usually, Clarke 1866 means a NAD 1927 datum. However, ...
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After finding this comment, I searched for this spatial_ref_sys table and inserted it into to my PostGIS database.
Reloaded the shapefiles into PostGIS in ESPG: 900913.
Restarted TileMill, added my PostGIS layers, and they are all layered correctly.
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You are calculating area here, so there are two different factors that you need to take into account.
The first and most important is the fact that since your data is in Decimal Degrees, you will not be able to perform a linear calculation for the true area of your raster cells. Since the lines of Longitude converge at the Poles, the distance represented ...
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