Creating Moving Maps of the Goldfields

[BigWave]

Hope most of you can now load your map into QGIS using the correct Zone number.
Geo-referencing will be detailed tomorrow, and you'll find it a breeze.
It takes me around 5mins max to load a map, geo-reference and check it ready for use on my PC.
It generally takes me longer than this to create a GeoVic map in the first place.

PS: Even though we've been discussing GDA94 above, some may wonder about the new Australian (GDA2020) datum being introduced.
Well, by the year 2020, Australia will have moved approximately 1.8m NNE (currently moving around 7cm each year) from when the GDA94 datum was established, so the Map Grid of Australia (MGA) using the DGA94 datum will be 1.8m out (i.e.: the grid was set, and our landmarks have moved wrt it as Australia drifts).

A similar thing is happening around the world, so the global community has decided it's time to move the world's datum, and have chosen where we expect it to be in the year 2020. In line with this, Australia has reset our datum to GDA2020.
Most mapping agencies used by mines, councils etc., have either swapped to this datum (GDA2020) or are in the process of doing so.
For us prospectors though, 1.8m is generally not significant.
I mostly use GDA94, but will swap to GDA2020 for that extra smidge of GPS accuracy. Bugger all difference for me in the goldfields!

 

[MegsyB007]

This is really informative and has answered a lot of my questions so far, BigWave - thank you! A very interesting thread. Please keep going. erfect:

 

[Dignit]

Very comprehensive explanation BW. :Y:

 

[BigWave]

Thanks dignit!
Most Aust map users can forget most of the above, just not GDA94 (or GDA2020), then MGA, then your Zone.
I just did another Geo-referenced map of Lillycur (the Vic GT), but used Zone 54 instead of 55, which put it out (way to the West) into the sea off Adelaide.
I'd had a few rums.
I haven't done that in a while.
Get your MGA Zones right (otherwise your Eastings are useless)!

 

[BigWave]

Tomorrow is where we can forget about most of the above background (maybe some has sunk in) and learn easy steps to geo-reference an MGA map using QGIS.
You can then start navigating accurately around the select area, and make sure you stay out of prohibited areas!
Just remember to use the GDA94 (or GDA2020) datum; the MGA grid reference system, and the correct MGA Zone for your area!
If you have outstanding questions that you feel that I may have missed, then please ask on the forum.
If you have more sensitive questions (i.e.: new PC users etc.,) then please PM me, and I'll try to help, one-on-one.
It now gets simple folks!
PS: Most modern GPS units should be able to switch between Lat/Long and UTM (Eastings and Northings).
That is the way modern nav is going, so get used to it. It's far easier to use!

 

[WhiteyCQ]

Thanks BW, Im away at the moment playing with our new 5000 but when I get home Ill study your great directions and hopefully be setup. I asked a question for this a few days ago and really appreciate your help and time for us, cheers mate. Brad

 

[Northeast]

Hi BW. I still haven't had time to play with the whole map stuff but thanks for the explanations and the zone thing makes sense now.

The GrassGis thing is here on the QGIS download page - https://www.qgis.org/en/site/forusers/download.html - I think that is what they are calling the latest version 3.whatever or it is the installer or something. It all looked either really weird or just a little different to your screen shots until I downloaded the exact same version as yours - then I was in business :Y:

Here is a question for you that is probably a really dumb one. How do I get the map I create on here onto my phone? Email it is the only way I can think to do it. I use Avenza maps and always wanted to be able to get the maps that I have downloaded onto Avenza and move them onto my PC so that I can add things in and make notes, etc and then move them back again onto my iPhone. Any idea if that can be done?

Avenza works great but its usability just on my phone is limited.

 

[BigWave]

Geo-referencing:
1. Open QGIS

2. Install The Geo-Referencing Plug-In
If geo-referencing has previously been used, then it is likely that the Geo-referencing plug-in tool has been installed.
If this is the first time Geo-referencing is being used, the Geo-referencing plug-in tool will need to be added.
Do this by selecting the Plugins on the top Menu Toolbar, select: Manage and Install Plugins, then scroll down and select Georeferencer GDAL. Then select Install Plugin (on the lower right).

The Georeferencer will now be downloaded to QGIS. You only have to do this once.

3. Now we can start the Georeferencer:

Note: This is where all future geo-referencing begins. The previous posts were for QGIS and MGA/Zone familiarity only.

Select Raster on the top menu toolbar, then Georeferencer and # Georeferencer in the drop-down menu.

A blank geo-referencing screen will now be displayed, with the upper section shown below. Select Open Raster icon.

This one (from GeoVic) shows a clearly marked MGA grid which will greatly aid geo-referencing.

Browse to find your map file, select it, then click "Open" at the bottom right.

Now select the appropriate Coordinate Referencing system (in this case: GDA94 / MGA Zone 54). You will need to set your map's MGA Zone as was discussed in detail above.

Press OK. The following Geo-referencing screen will now be displayed. This one shows my TIFF map of the Lillycur, Amherst and Talbot area:

The next step is to select the appropriate Geo-Referencing Transform (the way the MGA coordinates are applied to the pixels).
Select the Transformation Settings icon.

The Transformation Settings screen will now be displayed:

For a good, undistorted map - like the ones from GeoVic, leave the default Transform Type and Resampling method as shown.

You can check that the appropriate Coordinate Reference System has been entered ("Target SRS" - this is an error - it should be "Target CRS") by clicking this tab. Change it if necessary.

Now enter the Output Raster file name. This geo-referenced file will end up in the same directory as the original map. I like to add "_ref" to the file name to show that it has been geo-referenced. Remember to add the appropriate file type (.pdf , .jpg or .tif). In my case you can see that I am geo-referencing a TIFF file by using the .tif file type.
Finally, if you check the "Load In QGIS When Done" check box at the bottom, the file will automatically be loaded into the QGIS main screen.

Now we add the Ground Control Points (GCPs). I use 4 GCPs spread in a rectangle around the map's outer edge, and I am in the habit of loading in the following order (Lower Left, Upper Left, Upper Right and Lower Right.

Now select the pan tool (hand icon) at the top of the screen, move to roughly centre the first point to be referenced (in this case the lower left) and use your mouse scroll to zoom in to where you start to see pixels. Then select the Add Point icon (refer pic below).

Then place the mouse cursor over where the graticules intersect and click to select that point.
At the prompt, type in the Easting and Northing coordinates (in this case 732000 and 5881500), seelect OK and the first GCP should be loaded as shown below:

You will see a small red dot on the map where you added this first GCP and will see details of this first GCP at the bottom of the screen.
Check that the MGA coordinates are correct.
Note 1: beside the Add Point icon at the top of the screen, there are also "Delete Point" and "Move Point" icons.
Note 2.you will note I have added a yellow box next to this first GCP on the map. I normally don't use these, and you likely will not see it as it is a set-up option in the "Settings" menu (on the tool bar at the top of the screen - under "Configure Georeferencer").

Now select the pan tool again, pan and zoom to the second point to be geo-referenced (upper left), select the Add Point icon and reference this GCP.
Continue to reference all 4 GCP. You should now see the following screen:

You can then check the GCP data that you have entered in the GCP table at the bottom. Edit if you need to.

That's it!

Now click the "Start Georeferencing icon at the top left, and within a few seconds (hopefully), the geo-referenced file will be stored it the directory next to the original (now marked with an "_ref" or whatever you chose), and it should be loaded in the QGIS main screen.

Now minimise the Geo-referencing screen and you'll see your geo-referenced map loaded in QGIS. It should look exactly like the original (not skewed).

Now, when you move the cursor over the map, the MGA coordinates will be shown the bottom panel (previously these were pixel coordinates). The GCPs that were used have small red dots indicating them, and the CRS designator is seen bottom right (in this example, EPSG:28354 is the designator for GDA94 MGA Zone 54).

That's it. You now have your first home-geo-referenced map

 

[BigWave]

Recapping:
1. Open "Raster" - "Georeferencer" - "# Georeferencer" (5 secs)
2. Select "Add Raster" icon (5 secs)
3. Select File (5 secs)
4. Set the Coordinate Reference System (CRS) (5 secs)
5. Select the yellow cog icon to set Transformation Settings and output file name (if you forget this step, you'll be prompted later) (20 secs)
6. Add 4 Ground Control Points (GCPs) (1 min each)
7. Start Geo-referencing. (5 secs)

All up: 4min 45 secs

 

[BigWave]

Now to play with the geo-referenced file.
Firstly, you'll need to display the GPS information panel.
On the QGIS main screen, this is normally found at the: View/Panels/GPS information Panel as shown below. Check the box and close the menu.

The GPS Information Panel will now be shown. I find it preferable to drag it to the far right of the screen:

With:
1. an appropriately loaded GPS (internal or external with S/W driver loaded) and
2. a reasonably un-shaded skyline,
3. Autodetect selected (I use an external GPS and forget which Comm port each USB socket is, so I use Autodetect)
tap the Connect button at the top right of the GPS Information Panel.
Note: If the GPS has been recently been used and has not changed location significantly, establishing a connection may only take a minute or so. If not used recently or has been moved significantly, then establishing a connection may take 10 mins or so. Be patient.
If a good GPS signal is present, a green box should appear in the upper RHS of the GPS Panel. Yellow means a medium GPS signal (useable, but try for a better one) and red means poor or no GPS reception. The major functions of this screen are shown below.

There are other screens that can be selected on the GPS Information Panel, including:

All going well (with good or medium satellite connection), the map should have centered (if Map centering is set to always as shown above), and moves as the GPS is moved.

Note 1: If the cursor is seen but on a white screen (i.e.: no map), then it is likely that the map was incorrectly geo-referenced (probably the wrong Coordinate Reference System was used) and has been pushed from the screen. Place the mouse cursor on the screen and read its coordinates on the bottom of the screen. If the Northing is roughly where expected, but the Easting is wildly off (it can never be less than ~166,000m or more than ~834,000m i.e.: the centre Easting for each Zone is exactly 500,000m), then the wrong MGA zone was likely used. In this case, the map will need to be geo-referenced again using the correct Coordinate Reference System.
Note 2: The map may be moved manually by using the pan (hand) tool, but should soon be re-centered. Even without moving the GPS, re-centering will only happen when the GPS calculates that it has moved due to the changing satellite constellation (and accuracy), and may take a while under stable GPS conditions.
Note 3: To check the locational stability, it is worth zooming the map right it (until the pixels are quite large) and watching the location track wander. By moving the mouse cursor from one edge of the track pattern to the other edge, the distance may be measured. If used inside, or with poor GPS reception, the wandering will be much more significant.

 

[BigWave]

How do I get the map I create on here onto my phone? Email it is the only way I can think to do it. I use Avenza maps and always wanted to be able to get the maps that I have downloaded onto Avenza and move them onto my PC so that I can add things in and make notes, etc and then move them back again onto my iPhone. Any idea if that can be done?

Avenza works great but its usability just on my phone is limited.

Hi NE. I find Avenza's "PDF Maps" to be a great app for using geo-referenced TIFF maps on your iPhone.

1. Connect iPhone to PC.
2. Open iTunes.
3. Select the phone/tablet icon at the top

4. Select File Sharing and scroll down to PDF Maps (or whaatever app you are using)

5. Select PDF Maps, then a list of shared maps will be displayed on the screens RHS. Scroll that down to where you can see Add File (near the bottom right).

6. Browse to your geo-referenced TIFF map, and select Open.
7. Open the app (in this case Avenzas PDF Maps) on the iPhone or tablet.
8. In the GPS Maps map area, click the + (Import Map) tab.

9. On the phone/tablet Import Map page, select: From iTunes Sharing
10. Then select the file to be imported and on clicking Import at the bottom of the screen, the file will be imported to PDF Maps.

Note: If you are currently on the map, below the map name it will state: On map
Otherwise, it will state the distance and show an arrow direction to the map.
This is a handy feature of GPS Maps, showing if you are on a desired map or how far youre from it (including an arrow showing direction).

11. To delete a map on PDF Maps, just swipe right to left over the map name, and choose delete.

 

[diggit]

Hats off to you BW, great write up.
Clear, concise and well thought out.
You could be a lecturer in some university if you ever decide to break your retirement.

 

[BigWave]

Thanks diggit, but I'll plug away at retirement for a bit longer

 

[BigWave]

Same I downloaded it but thats as far as I can get being as dumb as a post when it comes to computers. Sorry bigwave I cant get past the blank page 8.( . Its my first laptop at 41

Ho Whitey. Drop me a PM with your phone number, and I can talk you through it.
For anyone else with questions, ask here or send me a PM.
I reckon that you'll love using your best geo-referenced digital maps of the goldfields.
I have 38 of my own geo-referenced maps, mostly of the Vic GT, but some of FNQ cattle stations and leases in WA. I have also downloaded 8 free maps of Vic Parks provided by Parks Victoria
Cheers
BW

 

[Fnx50]

Hi BW. I'm on board. Some of it is a bit confusing for me, but I'm hanging in there. Thank you mate.

 

[BigWave]

Just go slowly the first few times mate. You'll pick it up and it will become natural.
Ask here, or PM me with any questions.
I hope I can answer them, though there are probably many members here who can answer if I can't.

 

[StoneTheCrows]

Thanks BW

I am with Fnx, almost there
Thanks for the time and effort - very helpful.

I am only doing my local area (no gold) just to get the hang of it
soon I will get some pdf maps of Hill end and surrounds.

 

[Dignit]

BW
From what I could see last night Avenza PdfMaps uses a US based datum set. You can't select MGA/GDA that I could see. So the Easting & Northing that shows on Avenza isn't the same as MGA/GDA Eastings & Northings that you would see on a Geovic Map or Handy GPS. Do you find that an issue in the field?
I expect your location will show correctly on the moving map but the coordinates shown won't correspond to MGA/GDA coordinates.
I can always switch to Handy GPS if I want to give someone GDA coordinates.
Have I got this right?
Cheers Andy

 

[BigWave]

Hi Dignit.
The MGA coordinates should both be the same as they both use the same GPS.
To test this, I have just driven to the local pub (The Grand in Warrandyte) so as not to show my home address.
No, I didn't have a beer (it's a Monday after all) - so will wait till lunch time
I then fired up both Handy GPS and Avenza's PDF Maps on my iPhone.
I loaded a local file (previously geo-referenced using GDA94) onto PDF Maps, and viewed the displayed coordinates on both.
They both display identical MGA coordinates.
Not just close - but exact.

They also showed the same image location (although one being a map and the other a sat image) - on the footpath exactly across the road from the car-park entrance.
So clearly, I didn't have the "wobbly boot" on when I geo-referenced my local area map.
Both apps are great - they just do different things.

 

[Pro-oz]

Hi BW, I am running a bit behind I now have QGIS installed. You have been to Western Creek would a scan of the supplied map of Western Creek work with this?