Hi 
 
When searching for survey marks I came across this link that lists the known 
survey marks, http://www.dpiw.tas.gov.au/inter.nsf/Attachments/NBON-75X7RM?open 
in a CSV format for Tasmanian.  Not suggesting that this is imported into OSM 
as not aware of the copyright issues but at long last I have come across 
something that will enable me to check my Garmin 62s' accuracy and give the 
ability to align Bing when I find them on the ground providing that they can be 
seen from Bing.  Be great if they are in nice circles of paving but something 
tells me I will not be that lucky but a bit of averaging should get a couple of 
metres of accuracy.   This will means I can fix up some roads (split lanes) 
alignment so I am not told to turn-around and go back as happened to me in 
Launceston.   Also avoid GPS wars where mine is better than yours as I have 
noticed when playing with GPS that one brand is consistently 10 or so metres 
out.  Also spotted something similar when checking my traces to other traces 
loaded into OSM.  
 
Been reading up on GPS accuracy and playing with averaging waypoints on the 
Garmin 62S and have realised that WAAS does not work outside the USA and for 
some units better to have it switched off.  If I wrong in my understanding 
please let me know.  I can be rather a precision freak but be nice to get thing 
right.  Still interested in the most accurate GPS outside professional units 
but given the WAAS issue tend to think USA based comparisons are flawed.  Did 
find an interesting article from the Berkeley University GIS section where high 
end standard consumer GPS actually perform better than some of the professional 
units where base station correction is not available or reception is 
compromised by locational issues such as tree cover.
 
Now it would be great to permanently align Bing in Polatch 2 but this does not 
appear possible and I need to read up in JOSM to find the means to do this.  
Generally finding Bing around 10 metres or better correct in native format 
(assuming my GSP is that good) but some tiles the overlap can be out by more 
than that which is especially noticeable on things like lakes that cover more 
than one photographic tile
 
Cheers Brett
                                          
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