Re: [talk-au] Australia "changing coordinates"

2016-08-02 Thread Warin
On 8/2/2016 3:37 PM, Andrew Davidson wrote: WGS84 is a datum fixed; as in dated 1984 and the data does not change. I'm not sure that you've understood exactly what a semi-dynamic datum is. Have a read of this: http://ceur-ws.org/Vol-1142/paper6.pdf particularly sections 3.4 and 3.5. I'm

Re: [talk-au] Australia "changing coordinates"

2016-08-02 Thread Andrew Harvey
I found this explanation helpful http://www.geoproject.com.au/gda.faq.html#q16 On Tue, 2 Aug 2016, at 01:57 PM, Andrew Davidson wrote: > What to do about it? Unfortunately the changeover to GDA2020 is not > going to happen overnight, the plan is for a three year transition > starting in 2017.

Re: [talk-au] Australia "changing coordinates"

2016-08-01 Thread Andrew Davidson
WGS84 is a datum fixed; as in dated 1984 and the data does not change. I'm not sure that you've understood exactly what a semi-dynamic datum is. Have a read of this: http://ceur-ws.org/Vol-1142/paper6.pdf particularly sections 3.4 and 3.5. Or you have access to survey points/marks and

Re: [talk-au] Australia "changing coordinates"

2016-08-01 Thread Warin
On 8/2/2016 1:57 PM, Andrew Davidson wrote: It's interesting because it highlights one of the foundation myths of OSM; which is that it uses the "WGS84" co-ordinate system. This is a convenient myth and if you're talking about only mapping to the nearest 5m then it is in effect true. However,

Re: [talk-au] Australia "changing coordinates"

2016-08-01 Thread Andrew Davidson
It's interesting because it highlights one of the foundation myths of OSM; which is that it uses the "WGS84" co-ordinate system. This is a convenient myth and if you're talking about only mapping to the nearest 5m then it is in effect true. However, once you start talking about sub-metre

Re: [talk-au] Australia "changing coordinates"

2016-07-30 Thread Warin
On 7/30/2016 1:57 PM, Andrew Harvey wrote: On Sat, 30 Jul 2016, at 08:40 AM, Warin wrote: The change, distance wise, is upto 1.5 metres, well within commercial GPS uncertainties. The change is to the datum. How this will work out with future global datums we will have to wait and see. In

Re: [talk-au] Australia "changing coordinates"

2016-07-29 Thread Andrew Harvey
On Sat, 30 Jul 2016, at 08:40 AM, Warin wrote: > The change, distance wise, is upto 1.5 metres, well within commercial > GPS uncertainties. > > The change is to the datum. How this will work out with future global > datums we will have to wait and see. > > In another 30 years there will

Re: [talk-au] Australia "changing coordinates"

2016-07-29 Thread Warin
On 7/29/2016 10:40 PM, Andy Mabbett wrote: See you when you reach England ;-) http://www.bbc.co.uk/news/technology-36912700 But seriously: what impact might this have, on OSM? Very little! The change, distance wise, is upto 1.5 metres, well within commercial GPS uncertainties. The

[talk-au] Australia "changing coordinates"

2016-07-29 Thread Andy Mabbett
See you when you reach England ;-) http://www.bbc.co.uk/news/technology-36912700 But seriously: what impact might this have, on OSM? -- Andy Mabbett @pigsonthewing http://pigsonthewing.org.uk ___ Talk-au mailing list Talk-au@openstreetmap.org