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Converting Wgs84 To British Grid Or Lat/long


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I am trying to convert the Degrees Minutes Seconds given on the Cache pages to either British Grid or Lat Long but it wont work.

 

I have found loads of programs on the net but they just dont match up when I put them on Auto Route. Its really annoying me now I just dont know what I am doing wrong.

 

I know it does show the British grid on the page but I am looking at parking etc not the actual cache site.

 

I am practising with the actual cache site though so I can compare and check the ones I convert but when I convert them it is putting me in the genral area but about 10 miles off.

 

Can anybody help me PLEASE!!!

 

Thanks

Rebecca :rolleyes:

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I am trying to convert the Degrees Minutes Seconds given on the Cache pages [snip] I have found loads of programs on the net but they just dont match up when I put them on Auto Route.

As others have pointed out, the coordinates on the cache pages are given in degrees and minutes, rather than degrees, minutes and seconds.

 

I'll just chip in another webpage which does coordinate conversions. :unsure:

 

Also, if you view the cache pages via the GeocacheUK stats pages, all coordinates on the page will have OS grid references, including any references to car parks etc.

Edited by Teasel
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In general, if you want to retain accuracy when converting back and forth, it's best to use either GridInquest or the official OS website for the conversion.

 

The inbox conversions by most GPSrs are over-simplified calcs which introduce an error of several metres. That was OK back in the bad old days of SA and without Differential corrections, but modern GPSrs with WAAS are greatly more accurate than their own OS conversion algorithms.

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I've adapted the conversion code used on Geograph.co.uk and Nearby.org.uk into javascript, which should open up a few more possibilities on the "GreaseMonkey" front. I haven't written any documentation yet, but if anyone wants to "beta test" it, drop me an email.

 

It's accurate to approx 7m for 90% of the UK, I just need to document it and add some convenience methods to make "real world" applications a little easier.

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