Questions tagged [wgs84]

WGS 84 (that spelling) is the name of an ellipsoid (EPSG::7030), the name of a geodetic coordinate reference system (EPSG::4326), and the alias of a datum (EPSG::6326), official name World Geodetic System 1984. WGS84 (no space) is the alias of the ellipsoid (EPSG::7030). WGS 84 is most commonly used to describe the coordinate reference system.

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13
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4answers
30k views

How do I calculate the bounding box for given a distance and latitude/longitude

I need to be able to calculate a bounding box or circle for a given WGS84 latitude and WGS84 longitude, and distance but have no idea where to start! The distance from the start Lat/Lon would be 10Km ...
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5answers
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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', { ...
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2answers
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ST_Distance versus ST_DistanceSpheroid?

As my client software uses lat/lon coordinates when communicating with my (spherical mercator) postgis database i decided to ST_Transform every geometry to WGS-84. However i noticed that ST_Distance ...
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1answer
728 views

Creating a User Defined Point Grid

Im trying to write some code (in C#, but any language will do) where the user defines and area, based on Min/Max Long/Lat's, and specifies a distance between points in meters, and the code returns a ...
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3answers
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Converting Ordnance Survey raster maps to WGS84 webmap tiles

I would like to generate Google/Bing-like map tiles from Ordnance Survey's 1:25000 and 1:50000 raster maps, which are provided as 4000x4000 UK national grid tiles (GeoTIFF). A sample tile can be ...
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2answers
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java vividsolutions jts wgs-84 distance to meters

my (java) project uses com.vividsolutions.jts.geom, which provides a distance function. After some googling I finally found that the return value from this function is in central angle degrees, when ...
4
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2answers
954 views

Project twitter geo data into WGS84 map

I'm currently working on displaying twitter geo data (currently just long/lat -> cartesian without any analysis). This is the world map (source: naturalearthdata): http://dl.dropbox.com/u/14747311/...
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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 ...
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2answers
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Measuring distance between points in ArcMap - what coordinate system to use?

This is a basic -newbie - question. I have some handwritten data points taken off a GPS - so I am assuming they are in WGS 84, and I want to load them in ArcMap 9.3, via excel, and measure the ...
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1answer
603 views

What is the DNSC08 Mean sea surface model ellipsoid based on?

Does anyone know what Danish Space centre DNSC08 mean sea surface model uses as the reference ellipsoid? there is no meta data on the web site: http://www.space.dtu.dk/English/Research/...
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3answers
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Converting WGS84 coordinates to British National Grid Easting/Northings using C#?

I'm looking for some code, ideally C#, to convert a WGS84 coordinate to British National Grid Easting and Northings. Does anyone have this to hand? I tried converting the Javascript code here: http:...
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1answer
853 views

Empty mapper window when I open a OSGB36 shapefile in MapInfo Professional. How can I see the data?

I have a set of shapefiles which I'm trying to open in MapInfo Professional 7.8. Each of the shapefiles has a .prj file which looks like this: PROJCS["British_National_Grid",GEOGCS["GCS_OSGB_1936" ,...
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3answers
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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 ...
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3answers
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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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1answer
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Matching ArcGIS and QGIS coordinate systems

I have the following info for a feature class in ArcGIS that is supposed to be in WGS 1984/UTM 16N projected coordinate system: Projection: Transverse_Mercator False_Easting: 500000.000000 ...
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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 ...
6
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1answer
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Converting Lambert Conformal Conic to WGS84 using Proj.4

I am attempting to transform data from Lambert Conformal Conic lat/long and I am having some issues with the results. The shapefile I am attemtping to transform can be found here: http://tfr.faa.gov/...
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3answers
761 views

Global grid, which reference system to use?

I have seen a couple global studies using WGS84 as geographic reference, with the problem that the area of raster cells is not constant. Which reference system would you use for a global analysis in ...
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4answers
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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 ...
129
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4answers
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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.
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1answer
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Convert from ITM ref to GPS ref?

How can I convert from ITM ref (Israel new map) to GPS ref and from GPS ref to ITM ref? I need any C# sample code or formula for this. For example: 32.086156,34.769239 = 178364,665948 Or : 29.548783,...