Bushwalk Australia

Can we expect new GPS units for the datum, or will the current ones be compatible?

I have never owned a gps unit but think it's something I should get soon enough. The new datum is expected in 2018 ish. New maps will be expected, and I wasn't sure how it will affect current gps units.

The impact of the difference from the new GDA datum is important for surveyors and those requiring highly accurate coordinates. The GDA2020 moves all Australian coordinates about 1.8m to the north and slightly east.

When the GDA94 was adopted to replace the previous AGD66 datum, this meant a difference in about 200m. This was when it was important to have the correct setting on the GPS, as if you were using an AGD66 datum on your GPS and a GDA94 map, it could mean you were 200m from your actual intended location.

The change from GDA94 to GDA2020 - the shift is not as consequential. For example, when you are using a 1:25000 topo map, the contour lines thickness is about 8m on the ground, so the 1.8m shift isn't really impacted heavily.

Anyway, you will notice that most GPSs if they don't have the GDA94 datum, they are set to WGS84, which is close to the GDA94, and very close to the new GDA2020. Given that your GPS will usually get between 3m to 10m of accuracy under good conditions, this is close enough for bushwalking navigation purposes.

I haven't seen topo maps using the GDA2020 projection as yet, and not sure when they will start being produced with the new datum.

My impression is that it makes no real difference to the current datum at the level of accuracy required by bushwalkers. I believe location references will change by about 1.8 metres. This is 1% of the change that occurred when we moved from AGD to GDA which was significant.

Great minds think alike!