GDA2020

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3 months 3 days ago #185 by Paul Craine
GDA2020 was created by Paul Craine
HI everyone - I'm a little surprised at the absence of GDA2020 conversations. I think we should all be a little more involved and active in this space - which can be lead by our spatial cousins - GIS. I think we have a role to play in educating our mine leaders that unlike 'Windows 2000' there is much more to modernisation and understanding the risks, effort any benefits for mines - and if this is even required.

Mines typically retain sustained data integrity via the AMS role, protection of the GPS base and its connections to the original control. Would an upgrade to GDA 2020, because it is now 2021 in name - mean better data protection ?

I think we need to be more vigilant with data coming IN / OUT - ie Government data (leases & contract UAV systems)

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2 months 3 weeks ago #186 by Kerry Matthews
Replied by Kerry Matthews on topic GDA2020
The benefits and need would hopefully be recognized by most surveyors, be they mining or otherwise but until there is some directive from a mining legislation level then justification will generally be difficult. Having a “reference” to GDA2020 is a totally different thing than “moving” to GDA2020. Moving a 50 year old datum to GDA is generally a scary proposition for many surveyors let alone management’s perceived risk

There will become a point where the risk of doing nothing will outweigh any properly controlled and managed planned approach. Many sites that implemented GPS say 20 years ago have basically very little functional ground control left and what is left is generally not enough to properly shift a site to any other datum let alone GDA2020.

Speaking from more a Queensland perspective this is especially the case with the many varieties of AGD over the years. This is not simply say an AGD66 v AGD84 thing but multiple versions of say AMG84 that can exist between two bordering mines. Which is right and which is wrong can be difficult especially when both may not be even actually correct (as such).

As for GIS, once a site is properly transformed and moved there will be a much reduced risk as long as GIS stay right away from historically archived site data, which is going to be difficult.

In regard heights and having done some very extensive comparisons of AHD and AusGeoid2020 over considerable areas, the benefits of AusGeoid2020 I believe can’t be stated highly enough. This is perhaps a whole separate subject?

There is already very real evidence where data sets have already become corrupted due to lack of vigilance and especially by those (typically non- survey type people) who don’t understand the issues.

For now GDA2020 is just fine, it is a very well defined datum, once a dataset is GDA2020 then moving forward (or backward) is fairly straight forward but I will leave the term “Dynamic” totally out of this discussion. That’s another story approaching 2023!

The difficult part is typically moving from some obscure version of datum XYZ in the 1960’s or 70’s or 80’s to absolute GDA2020, especially when all the original ground control is gone and you only have a GPS base. The other issue is not all the local state control is perfect either and especially ellipsoidal heights.

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