+Andy Lawrie Posted June 11, 2007 Share Posted June 11, 2007 The British National Grid References given for caches rarely correspond accurately to the latitude and longitude. I first noticed they typically were about 8 metres out compared to my own software, so I visited the Ordnance Survey web site and confirmed that my own references are accurate to about 1.5 metres, and the geocaching ones are typically 7 metres out. Are the co-ordinates on the geocaching web pages computed from the lat/long, or entered separately? Rgds, Andy Quote Link to comment
+OldNickCov Posted June 12, 2007 Share Posted June 12, 2007 The British National Grid References given for caches rarely correspond accurately to the latitude and longitude. I first noticed they typically were about 8 metres out compared to my own software, so I visited the Ordnance Survey web site and confirmed that my own references are accurate to about 1.5 metres, and the geocaching ones are typically 7 metres out. Are the co-ordinates on the geocaching web pages computed from the lat/long, or entered separately? Rgds, Andy Calculated Quote Link to comment
+Andy Lawrie Posted June 12, 2007 Author Share Posted June 12, 2007 Thanks Nick. They must use a very poor algorithm. Even the "quick and dirty" method published by the OS gives 1.5 metre accuracy, and the OS freely provide algorithms, worked examples, DLLs and even full applications to a very high degree of accuracy. Any idea if there is anyone at Groundspeak I can take this up with? Rgds, Andy Quote Link to comment
+eagletrek Posted June 12, 2007 Share Posted June 12, 2007 Thanks Nick. They must use a very poor algorithm. Even the "quick and dirty" method published by the OS gives 1.5 metre accuracy, and the OS freely provide algorithms, worked examples, DLLs and even full applications to a very high degree of accuracy. Any idea if there is anyone at Groundspeak I can take this up with? Rgds, Andy Only if you can spell meter correctly, Mate!!! Quote Link to comment
+Kiwi Nomad Posted June 13, 2007 Share Posted June 13, 2007 (edited) Thanks Nick. They must use a very poor algorithm. Even the "quick and dirty" method published by the OS gives 1.5 metre accuracy, and the OS freely provide algorithms, worked examples, DLLs and even full applications to a very high degree of accuracy. Any idea if there is anyone at Groundspeak I can take this up with? Rgds, Andy Only if you can spell meter correctly, Mate!!! metre or U.S. meter n. a metric unit of length equal to aprroximately 1.094 yards Spelling taken from Collins Shorter English Dictionary. Printed and bound in Great Britain. As stated on the cover 'The Authority on Current English' as different from American English. Edited June 13, 2007 by Kiwi Nomad Quote Link to comment
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