The coordinate system known as World Geodetic System 1984
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Map projection in OpenLayers
I want to overlay some data whose projection is WGS-84 on Google map layer in OpenLayers. But I just can't make them in the right place. I did as follows:
map = new OpenLayers.Map('map', {
...
5
votes
2answers
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How is EPSG:4326 data 'projected' in a 2D map?
I like to think I'm relatively well-versed in datums, projections, and coordinate reference systems, so if this is a stupid question I will suffer eternal shame.
OpenStreetMap data is stored in WGS84 ...
8
votes
2answers
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How do you compute the earth's radius at a given geodetic latitude?
(I see there is an equation on wikipedia that does exactly what I am asking but there is no references. I have no way of confirming the validity of this equation!)
I already understand the difference ...
2
votes
0answers
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OSGB36 to WGS84 reprojection 'error'
First off, I am a recent convert to QGIS and am greatly impressed with its ease of use and speed compared with the ESRI products with which I am more familiar - my congratulations and thanks to its ...
1
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3answers
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Convert Lambert Conformal Conic to WGS84
I am trying to convert my "Lambert Conformal Conic map with 2 standard parallels" to the basic/standard WGS84 projection that Google Maps use.
I have 30 of these maps which I need to convert. They ...
6
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2answers
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Converting projected geoTiff to WGS84 with GDAL and Python
Apologies if the following question is somewhat stupid, but I am only VERY new to this whole GIS thing.
I am trying to convert some projected geoTiff images to WGS84 using gdal in python. I have ...
8
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3answers
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Looking for a pythonic way to calculate the length of a WKT linestring
I was quite unsatisfied with Calculating Length of Linestrings in WGS84 in Miles. It kept me wondering if there is a more convenient, Pythonic way to calculate the length of a WKT linestring according ...
6
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3answers
316 views
How do I get the area of a WGS84 polygon in square meters?
The following gives me the area of the polygon in square degrees:
SELECT ST_Area(ST_GeomFromText('POLYGON((871325.790874952 6105405.3261047,871418.748307692 6105359.72944624,871346.22022442 ...
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2answers
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Converting X,Y coordinates to lat/long using pyproj and Proj.4 returns the wrong coordinates
I'm writing a python script that reads multiple XML files containing x and y coordinates and combines them all into a single csv file. Latitude and Longitude are required fields in the csv, but I am ...
4
votes
4answers
847 views
OSM To Postgis & WGS84 problems
I’m trying to import OpenStreetMap (OSM) data into postGIS it doesn’t appear to be working in that features do not appear to be in the correct place..
Using the QGIS OSM add in and a coastal shape ...
3
votes
4answers
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How to recalc WGS84 Shape_Area field to square miles in ArcGIS 10
What are the units of the Shape_Area field in a wgs84 feature class? Is it decimal degree squared?
I would like to convert that to something more meaningful like square miles without reprojecting the ...
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2answers
813 views
0
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2answers
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Converting from British National Grid (27700) to WGS84 (4326) to Web Mercator (102100)
I'm developing a web application that uses ESRI ArcGIS to display a map using JavaScript.
We are holding all our data in MS SQL Server 2008 as Easting/Northing against the British National Grid. ...
