Conversion of Map co-ordinates.

[user 14190]

Just wondering if anyone knows how to convert the old John Tully Maps which were in MGA (Map Grid Australia) to what ever system we are using now, have a few co-ordinates that we wrote down a number of years ago, some places not on the John Tully Maps and would like to be able to visit them again by converting to the current system, what ever it may be so we can use our Garmin Rino which does not have the old system from what we can see.

When I was looking at trying to do a conversion, we moved Australia 2 meters about 4 years ago through another change of systems, I was not able to work out which direction we moved it though :lol: :lol: :lol:

Graham

 

[Pete E]

Not sure if this is what your on about but have a read of this:

https://ozultimate.com/canyoning/map_grids.htm

About half way down it mentions converting between the old system and the present day one...

 

[BigWave]

Using the older MGA94 will only put you out by around 1.8m compared with the newer MGA2020.
Given that your GPS error is likely to be that or more, using MGA94 shouldn't put you at disadvantage.
In that time, Australia has moved ~1.8m NNE.

 

[user 14190]

Ok, thanks for that information PeteE and BW. Our problem was that it was an area that we went to on the last day of our holiday back about 15 years ago, did not go down there for a few years and then went with different GPS and settings, understanding numbers have not been much of a success for me, we have tried a number of times to find the location by driving and memory, but have not been able to locate the site again, a lot look like it until we start wandering and then realise that it is not where we are looking for, so as I took the co-ordinates at the time we want to try again. When I tried the conversions earlier, I either had too many number or not enough, so will see how I go this time, and I agree that the 1.8m is not enough to cause any problems. Thanks for the help. :Y: :Y: :Y:

Ok, just did a search and the co-ordinates that I have put me in the middle of Maryborough :lol: :lol: will just go back to looking a bit harder, Thanks.

Graham

 

[Nightjar]

2lateagain,
Not expecting you to put up your actual co-ordinates. layful:
Post an example so we can see what format it is in, then you may get an answer?
eg: 505210N 1153903W) or UTM Zone 11 is represented by 11U 594934 5636174

 

[user 14190]

Nightjar, have no problems with putting up numbers, first bit that wife found 15 years ago was here 39807 & 89362 These numbers are near the Prince of wales reef along the Blacksmith Gully Road, the numbers I was looking for have put me in the middle of Maryborough, I assume at the caravan park we use, so at this point a bit lost as to where or when I have got the wrong numbers written down, oldtimers disease I will put it down to. :awful: :awful: :awful:

Graham

 

[bob]

I have sent you a personal message with a possible solution. I didn't place the solution here because it would give others an open invitation to a spot that you would obviously like to revisit. I hope my solution is correct. Hope you find what you're looking for.

Cheers Bob.

 

[davsgold]

Nightjar, have no problems with putting up numbers, first bit that wife found 15 years ago was here 39807 & 89362 These numbers are near the Prince of wales reef along the Blacksmith Gully Road, the numbers I was looking for have put me in the middle of Maryborough, I assume at the caravan park we use, so at this point a bit lost as to where or when I have got the wrong numbers written down, oldtimers disease I will put it down to. :awful: :awful: :awful:

Graham

I don't know what those numbers you put up are, but this is the UTM coordinate for the turnoff onto Blacksmith Gully rd from the Highway

54H 740824m E 5887420m S as shown in Google Earth set on using Universal Transverse Mercator (UTM)

Once you have your coordinates accurately set in Google Earth you can then change the system in options setting and it will display the same spot in a different coordinate type.

Example the same spot for Blacksmith Gully rd now changed to Degrees Minutes Seconds are 37 7'43.00"S 14342'39.28"E

In Google Earth just go to the tools and then options and then select which ever coordinate system you want to convert to

cheers dave

 

[user 14190]

bob, have not received an email as yet, not worried about the co-ordinates as they were something that we did a long time ago, many others have been there since, but I know the location where they are and I am trying to work out why another set of numbers are not showing an area a lot further to the north of Maryborough.

davsgold, so it looks like we were using the UTM settings as they puts us close to the area that I was referring to. The GPS that we had at the time was the Garmin Geko which has since died, and not knowing much about what to use we just went with what ever was on the GPS, now just have to learn how to use Google earth a bit better, think we have located the area, but now I will try with the UTM settings to see if it is in the correct area.

Thanks to all for the assistance.

Graham

 

[davsgold]

G'day Graham

You can also change the coordinate system on a GPS as well, we use Garmin etrex 30 which you can change and alos a garmin etrex 10 you can change, and a Magellan explorist 500 all these GPS units have options to change to what ever you like to match up with.

We like UTM as it is a set of numbers unlike Lat/Long where there are three different systems and can put u way out of wack on a map

 

[user 14190]

davesgold, Have just realised that if I had read inside the front cover of the Tully map that I want to use I wrote the co-ordinates in that I had written "Position Format UPS UTM" but that was done many many years ago and I had forgotten, also bob sent some other info that I needed to add to get a result, also trying to use GeoVic which is causing a bit of an issue trying to work out how it works, I can tell those that are looking forward to retirement, it is good for the first 10 to 15 years, bit after that a number of things start to fail and technology goes forward at a rapid rate and if it was not for the spell check even I would not know what I was typing. Will stick to the UTM. :Y: :Y: :Y:

Graham

 

[Nightjar]

Graham,
Looks like Dave has put you on the right track with the UTM.
Just remember the same co-ords differ if you use UTM - Northings -Eastings or Southings - Eastings they put you in different locations.

Remember a few years back we used UTM co-ords for a campsite with a group meet here in WA.
A merchant navy fella came back with a sarcastic remark that the UTM's displayed would see us camping in the ocean off Tasmania.
:lol: We all arrived here on dry land at our designated destination north of Coolgardie.
**You were there Dave and would remember this, think it was Ted's meet?"

 

[user 14190]

Nightjar, I thought that I had it sorted, put in the co-ordinates that I have for the place I want towards Dunolly and ended up in NSW in the mountains in from Bega in an area that I have never been to and by the looks neither have too many other people, so have had enough for tonight, head is starting to hurt, way too much thinking going on for an old brain. :awful: :awful: :awful:

Graham

 

[Pete E]

The other possiblity is that perhaps the original co-ordinates were recorded wrong at the time?

As an example, one of the guys on a British MD forum had recorded the location of lots of his finds over the years using a handheld GPS...when he eventually went back over the data, he realised that he'd had the GPS sent up wrong and his locations were recorded with the wrong datum...

Might be an idea PMing the co-ordinates you have recorded plus a rough indication of the area to one of the more knowledgeable guys here on the thread and see if they will email you a snapshot of it marked on Google maps? If it looks right, all is well...

If it still comes up in the wrong state, it's likely the original co-ordinates are wrong...

 

[davsgold]

G'day Graham

Take note of the "ZONE" like around Maryborough Dunolly is in ZONE 54 H don't worry to much about the H when putting the coordinate but the ZONE has to be right. You only need to be near Bendigo for eg and the ZONE becomes 55 H

So if your putting in the coordinate on a hand held GPS in a different ZONE you need to have that number correct as well or you will be way out. Your hand held GPS know what Zone your in where your standing, and if you want it different you have to select the ZONE and type it in manually along with the rest of the coordinates, and make sure you click S for south on your GPS otherwise you might end up in the northern hemisphere somewhere. erfect:

In Google Earth with it set on UTM scroll around the VIC area and watch the ZONE change like 54H to something else as well as the easting and southings

So basically from around Bendigo to the east and south and north into NSW is ZONE 55H and from Bendigo west and north west up into NSW is ZONE 54H

cheers dave

 

[bob]

You guys are on the right track I think. I sent Graham a pm or email because I thought that he might want to keep his spot secret. Adding a seven to make 739807 and then fifty eight to make 58 8936. Using old MGA 94 data which is what the Tully maps used puts him in the area of the Prince of Wales Reef near Blacksmith Gully, north east of Amherst. 54 0739807 5889362 is a more recent co ordinate to the same place. Using WGS 84 his co-ordinates would be 54 H 0739807 5889362. According to Geovic data it is not right at the Prince of Wales Reef but it is close to it. If you knew what system your Rino GPS uses then I think that there are enough clues to work it out. I quoted you the wrong area number in the email I said that it was 55H when the area should be 54 H I think. Probably totally confused now but maybe of some help.

Cheers Bob.

 

[Pete E]

Graham,
Looks like Dave has put you on the right track with the UTM.
Just remember the same co-ords differ if you use UTM - Northings -Eastings or Southings - Eastings they put you in different locations.

Graham,

If you don't mind me asking but what are "southings" and when are they used as opposed to the more usual "northings"?

Also do the Australian Army use UTM for their land navigation?

Thanks in advance,

Peter

 

[Pete E]

Another crack at this..if you use the Military Grid Reference System, the original grid ref becomes 54H YD 39807 89362 ...this point is approx a couple of miles NNW of the Blacksmith Gulley Road turn off mentioned in Dave's post earlier....Does that look likely?

 

[user 14190]

Ok, Thanks all for the time, it looks to me that I have written down the numbers incorrectly as I have tried all the combinations and different grid references, but none come up in the area I am looking for towards the east of the Dunolly area.

davesgold, I became aware of the different zones while looking around and trying different combinations, but it was 54H, but it looks like I am going to have to master the google earth a bit better, what is available now is a lot clearer than when we looked for this area some years ago. :Y:

bob, the original co-ordinates were done on a Garmin Geko and then written down for safe keeping when we got back to the caravan, normally my wife checks what I have written as I have been known to make the odd mistake when transcribing, normally have no problem locating areas from memory, but the area we are looking for seems to have moved, will give it another try hopefully later in the year when we are clear to travel. :Y:

Pete e, to get to the settings I gave we did not have to go through private/cleared land, it was along the Blacksmith Gully road a couple of kms and then up a side track towards the Prince of Wales mine at the top of the hill. :Y:

All this could be one of the reasons when we owned a trailer sized boat my wife insisted that we stay on enclosed water, I thought that it was because she did not want to get sea sick, but I now think that she was worried where we would end up if I headed outside of the Heads at Jervis Bay with me as the navigator. :lol: :lol: :lol:

Just has been pointed out to me by wife that it was on the Blacksmiths Track, not the Blacksmiths Gully Road that the settings applied to that I gave. I am now going back to bed for a few days and when I get out again I hope that the fog that has formed in my head will have cleared, been locked up for too long I think. :awful: :awful: :awful: :awful: :awful:

Graham