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Trigpoints: Is there a point 0,0 in Australia?

Posted: 22 April 16 7:02 pm
by MavEtJu
Greetings,

I followed some links at Wikipedia and ended on the "Rijksdriehoekscoördinaten" (Government Triangle Coordinates in Dutch, see http://www.wikiwand.com/nl/Rijksdriehoe ... B6rdinaten if you are brave) page which said that the church is Amersfoort was for a long time the (0,0) coordinates in the Dutch mapping system. These days it's the (150 000, 463 000) coordinate so that you don't have the struggles of - and +'s and all your numbers in that country are positive integers. Way cool stuff.

Is there in Australia also a (0, 0) trigpoint, one where everything is measured from?

Edwin

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 22 April 16 10:52 pm
by fluffyfish
I've seen a point in perth cbd where it says all distances were measured from (in the old days). So maybe when it was relevant was before the Commonwealth so unlikely to exist??

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 1:40 am
by Chwiliwr
MavEtJu wrote:Greetings,

I followed some links at Wikipedia and ended on the "Rijksdriehoekscoördinaten" (Government Triangle Coordinates in Dutch, see http://www.wikiwand.com/nl/Rijksdriehoe ... B6rdinaten if you are brave) page which said that the church is Amersfoort was for a long time the (0,0) coordinates in the Dutch mapping system. These days it's the (150 000, 463 000) coordinate so that you don't have the struggles of - and +'s and all your numbers in that country are positive integers. Way cool stuff.

Is there in Australia also a (0, 0) trigpoint, one where everything is measured from?

Edwin
It has never been (0,0) as such but the Johnston geodetic station is he origin point on the surface of the earth for the old AGD66 datum and considered the source coordinate/measurement for all mapping for Australia prior to the adoption of GDA84.

See the following link which also has an image. http://www.ga.gov.au/scientific-topics/ ... -datum-agd

The 0.0 point in the CBD of Perth mentioned by fluffyfish only ever related to road distances not geographic coordinates.

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 11:02 am
by MavEtJu
Chwiliwr wrote: See the following link which also has an image. http://www.ga.gov.au/scientific-topics/ ... -datum-agd
Way cool, thanks for that.

It seems to be TP2871 (http://geocaching.com.au/cache/tp2871)

Edwin

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 12:31 pm
by Tyreless
In the NSW, the trigonometric survey in the mid to late 1800’s established two stations in Lake George to create the primary base line. There is a photo of the Lake George North Base in Tony Dawson's "Guide to the Historic Trigonometrical Stations of Sydney's North", but I couldn't fin a listing on the gca website (maybe someone can jump in here and point it out to me).

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 1:14 pm
by MavEtJu
Tyreless wrote:In the NSW, the trigonometric survey in the mid to late 1800’s established two stations in Lake George to create the primary base line. There is a photo of the Lake George North Base in Tony Dawson's "Guide to the Historic Trigonometrical Stations of Sydney's North", but I couldn't fin a listing on the gca website (maybe someone can jump in here and point it out to me).
And again I've spend an hour googling and perving on maps and trying to find out how things work....

https://www.craftact.org.au/exhibitions ... Hatton.pdf page 13 and following has pictures of them, but no coordinates.

Edwin

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 2:18 pm
by MavEtJu
And based on that map it seems that

TP4072 - Roseglen Homestead Area (Terra Mungula??? TS4321)
TP1109 - Collector Area

are the North base and the Eastern side of Lake George, but there are no pictures on these trigs yet to see if they are the same.

The other two at the west are not on a map (GCA or SIX maps)

Edwin

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 4:16 pm
by Tyreless
Great sleuthing to find that map. That shows an earlier baseline used for an incomplete survey of NSW in the early 1800's. The complete survey in the late 1800's used a different baseline. You can see the location oof the north and south base points on a map in this article:

http://xnatmap.org/adnm/docs/1genmap/ac ... ctgrid.htm

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 4:29 pm
by Tyreless
TS 776 Lake George North Base is shown on sixmaps. Looks like it might be TP0858 Butmaroo Area.

Re: Trigpoints: Is there a point 0,0 in Australia?

Posted: 23 April 16 4:49 pm
by Tyreless
TS778 Lake George Outh Base is on sixmaps. Looks to be TP1915 Turalla Homestead Area.