On 01/09/12 11:35, Russell Edwards wrote:
Thanks everyone for the replies. I have imported over 250 GPX traces
from my running log, boy does that slow JOSM down. It seems Bing may be
offset but having 100+ traces on some paths it is all just a big wide
blob of grey. Still, the blob is offset. I
On Sun, Sep 2, 2012 at 1:17 PM, 4x4falcon i...@4x4falcon.com wrote:
Actually I have to ask also why are you tracing from bing imagery when you
have gps traces and should be adding them as source=survey
Is that not the done thing?
GPS traces are usually 5-15 m in error in a random direction.
On 1 September 2012 11:35, Russell Edwards russell...@gmail.com wrote:
I am still curious to know what the positional accuracy of survey markers
is meant to be, if anyone can enlighten.
First question you have to ask is how old the survey is? Australia as a
whole moves north about 7-8 cm a
On 01/09/2012, at 16:58, Stephen Hope slh...@gmail.com wrote:
On 1 September 2012 11:35, Russell Edwards russell...@gmail.com wrote:
I am still curious to know what the positional accuracy of survey markers is
meant to be, if anyone can enlighten.
First question you have to ask is
But an even bigger error can be caused by using different projections. I
forget which one OSM uses, but using different projections can move a given
point 20m quite easily, and a survey marker may well be on a different one.
Can we get a definitive answer on this?
I think the terminology is
GDA94 to WGS84 is approx 45 cm from what I read but it will be affected by
continental drift. GDA is fixed to points on the Australian plate so GDA
coordinates will not change (much) but I guess OSM is really meant to be in
WGS84.
Just an update to this thread in case anyone is interested, I
On 02/09/12 10:14, Russell Edwards wrote:
GDA94 to WGS84 is approx 45 cm from what I read but it will be affected
by continental drift. GDA is fixed to points on the Australian plate so
GDA coordinates will not change (much) but I guess OSM is really meant
to be in WGS84.
Just an update to this
On 02/09/12 12:46, 4x4falcon wrote:
It's interesting that the traces from nearmap are misaligned as I said
previously their guarantee was that the accuracy was within 1m.
Not so interesting since we aren't using nearmap any longer, and many of
the nearmap traced ways have had their accuracy
Hi Russell,
Welcome aboard. Just my thoughts...
For a newbie, you've made some very astute observations about the accuracy of
the aerial imagery, so thanks for giving it the degree of thought - because
many others just dive in and start tracing without understanding these
subtleties.
You're
The bing imagery is out.
As per here:
http://wiki.openstreetmap.org/wiki/Bing#Precision
you need to align the bing imagery to either gps traces or source=survey
or source=nearmap.
Nearmap guaranteed that their imagery was within one metre, although
there are some areas that are outside
Agree with everything that Ben said.
In addition, you may like to check the AGRI imagery. If the Bing and
AGRI imagery align exactly, chances are you have well aligned Bing
imagery. If the AGRI imagery aligns well with traces, it is easy
enough to shift the Bing background to align with AGRI,
Thanks everyone for the replies. I have imported over 250 GPX traces from
my running log, boy does that slow JOSM down. It seems Bing may be offset
but having 100+ traces on some paths it is all just a big wide blob of
grey. Still, the blob is offset. I might try and cobble together a tool to
Russell,
Found this on a search. This might be your answer to average your tracks -
http://wiki.openstreetmap.org/wiki/Average_tracks
Sent from my iPhone
On 01/09/2012, at 11:35, Russell Edwards russell...@gmail.com wrote:
Thanks everyone for the replies. I have imported over 250 GPX traces
13 matches
Mail list logo
