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This model assumes the world is spherical, but earth's radius changes with the latitude. If the distance covers about 1/10 of a degree, and Earth's radius ranges from 6353-6384km, then the error can be over 400m. This might cause 10km to come out as 9km if you are aggressively rounding.


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For javascript you can use proj4.js. Its conversion function is called proj4.


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I solved by using conversion functions from proj4js.js


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For proj.4 those two mean exactly the same and conversion from one system to another changes only the EPSG code. If you work with geodetic problems which require accurate ellipsoid model you will need some other tools. # ETRS89 <4258> +proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs <> # WGS 84 <4326> +proj=longlat +datum=WGS84 ...


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This is my first venture into GIS datasets. Welcome to the world of GIS! However, the X/Y co-ordinates in my dataset are Ordnance Survey (GB) Easting and Northing. Ordnance Survey provide a very useful conversion spreadsheet (https://www.ordnancesurvey.co.uk/docs/support/projection-and-transformation-calculations.xls) to convert between ...


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Here's What you have to do : Set ArcMAP to NAD83. Load your XY data. Export them to a Shapefile. Project your Shapefile to wgs84 using the "Project" tool in Data managements toolbox.


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I like JB's answer above but will add two things. If the point locations are for a 'general overview' map then it might suffice to simply pan to each area where the site is located and create a point. At a large scale one point might cover an entire city or town as a visual representation. In that case the exact coordinates are not important at relatively ...


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I would separate the data into the various coordinate systems first and try to standardize the data in each as much as possible. Create a separate file for each coordinate system. If the data is in a spreadsheet, have a separate sheet for each coordinate system. Then you can use a single sheet to create a layer (shapefile or feature class) for each that is ...


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There is nothing wrong with your data. It is just the fact that OS still issues coordinates in OSGB36, while Google uses WGS84: So you have to assign EPSG:4277 to your degree coordinates, or EPSG:27700 for raster data in projected coordinates. Make sure that both projections have a `+towgs84' datum shift.



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