Geocaching Australia

Hi Guys Girls and Kids,
Been a long time since I've been on here or found a cache actually, been years.
A few of the originals will remember my name or or newbies may have found a couple of my remaining caches.

Anyhow to the point I've been searching and searching the internet trying to find this information but can't get it anywhere.
And with the wealth of knowledge I know that's in these forums I hope someone can point me in the right direction.

I've got myself a Garmin Edge 510 cycle computer, which to the point has a Barometric Altimeter.
now what I want to do is know the exact elevation of my driveway so when I head out for a ride I can just manually set the altimeter,

The value displayed on the Garmin is a blend of GPS and manually set barometer data,

Which varies greatly from my GPS elevation displayed on my very old Magellan Explorist 600 (which might get a sat lock in 10 minutes) talking maybe 20m elevation difference.

So my plan is to find a know elevation point in the local area Hornsby / Waitara (Sydney NSW) and set my Garmin Edge 510 to this known elevation.
Then quickly go home and measure the elevation of my driveway and then I know what to calibrate it to every time i leave home.

hopefully of all that makes sense?

So the real question is, Does anyone know where I can find a list of known elevation points for the local area?

Cheers, Glad to see the site running good as ever and look forward to maybe getting back into some caching when my little girl gets big enough to venture out into the wild.

Regards Martin Gins
AKA GIN51E

The NSW topo map. HORNSBY 91304S, NSW 25,000:1 has contour lines at 10 m intervals. OZI Explorer mapping software shows this map,so, looking at your Hornsby - Waitara area,

S 33 42.6051
E 151 06.1465

has an elevation of 190m.

Go down to the seaside, midtide and press "calibrate" with the GPS at water level?

Find your nearest accessible trig point. That will have a known elevation. It should be recorded on a toppo map.

Thanks guys I'll test them all out, only problem with the trigs is the 3 closest ones are all on top of buildings.

Just saw this locationless cache. Maybe there's a location here that can help.
http://geocaching.com.au/cache/ga4411

thanks geo_jas thats perfect, looks like they seem to be near sewage pumping stations, not the best places to hang out but looks like thats where i have to go.

Thanks Geo_jas

your post got me thinking and a message to a mate
(who's dad has something to do with surveying)
I asked him to check with his dad if he knew where any AHD markers were in the local area.

Next thing i get an email with pictures and diagrams showing the end of my street.
Showing a state survey marker SS19412 only 10M from my Driveway showing a AHD71 168.421M
I think thats more than accurate enough for my needs.

Cheers guys for all the suggestions.

Case solved