Bushwalk Australia

I have recently begun playing with Memory Map, but am perplexed about the coordinate datum used. I want to use either GDA94 or MGRS coordinates, but they are not available options.

Does anyone know if these patches can be downloaded?

Use WGS84, it should be close enough to GDA94.

That should be the case, but it's not working out so easily.

For example, let's use Mt Difficult in the Grampians as a test case (as I have a GDA94 paper map at hand).

Paper map: (zone 54) 2820 0308
Memory Map: 54S 628207 5903080
MGRS: 54H XE 2820 0308

From this, we see a difference, but relationship in that the Memory Map reading in "UTM on WGS94" has an extra digit at the start of the eastings and an extra two digits at the start of the northings.

The extra numbers & letter are correct, the notes on the paper maps about the whole of the numbers for a full GPS location are very poorly explained, I dunno why.

So add the S and 06 and 59 to your paper maps numbers and you will have a full set from that source .

As for being different I can only say I have not found a single peak in Garmin digital maps correctly located so shy should mem maps be different.

wander wrote: I have not found a single peak in Garmin digital maps correctly located so shy should mem maps be different.

The frustration and agony of garmin peak locations. If the hydro and contours weren't so damn useful...

The paper maps are set up to only need /use the significant figures that change on that sheet.
Also they round or actually truncate to the nearest 10 metres.
So the accuracy is within 10 metres which is insignificant for scaling etc, and within the tolerances or accuracy of features at that map scale. Technically they could better that and probably do.
Once you become accustomed to the way the coordinates work it's quick to find you way about the map, and it has meaning as you can measure purely by coordinate difference.
The map legend should explain how to or what prefix and suffix for those abbreviated coordinates to convert to true coordinates.
Not sure if that helps.

My experience with Memory Map for Tasmania is not good.
They seemed to get lost along the way in an ongoing conversation and then went cold.

Yeah, I am well versed in coordinates and certainly understand tolerances of accuracy of plot and measurements, but I am actually after a way of simply using MGRS rather than needing to cut off the first digits.

Why are you wanting to use MGRS ??? It is a system focused on Europe? And not reflected well if at all on civilian maps.

In Australian you need to be using GDA94 (WGS84) or AGD66 depending on your paper map. Anything else is an added complication (ie a waste of time ).

oyster_07 wrote:.............
For example, let's use Mt Difficult in the Grampians as a test case (as I have a GDA94 paper map at hand).

Paper map: (zone 54) 2820 0308
Memory Map: 54S 628207 5903080
MGRS: 54H XE 2820 0308
...............

A couple of problems here the S should be an H the zone is 54H not 54S and just zone 54 is incomplete.
Zone 54S is a long way north of the equator some 8000 km from Victoria and therefore a massive error.
Zone 54 is a 6 degrees of longitude "strip" of the earth extending from north to south, the H is an 8 degrees of latidude section of that "strip".
The full UTM coordinate 54 H 628207 5903080 is to the metre where the four number coordinate is to 10 metres.

This might help https://www.uwgb.edu/dutchs/FieldMethods/UTMSystem.htm

Wander wrote:Why are you wanting to use MGRS ??? It is a system focused on Europe? And not reflected well if at all on civilian maps.
In Australian you need to be using GDA94 (WGS84) or AGD66 depending on your paper map. Anything else is an added complication (ie a waste of time ).

MGRS is a coordinate system that can be used world wide.
GDA94 etc. are the map datums used for maps in our region.

Yes, I know what all these systems are, but my original question was whether anyone knows if MGRS can be used in Memory Map (and where I can get the file from).

Understand but based on where you wrote memory map put you (zone 54S) I don't think I'd bother using something that produces an 8000 km error. I might add that I don't know squat about Memory Map.

MM uses the system whereby the latitude bands (that are actually MGRS) are simply grouped as north or south of the equator.

As such, in this example 54S refers to UTM zone 54 south of the equator.

The 'extra digits' in UTM/WGS/GDA are effectively the latitude bands. In the above set, the extra digits are the 6**** 59****

Most maps print these extra digits very small and the grid lines are marked with the two digits following the 'extra digits'. MM however prints the complete number.

As I simply want to push these extra digits 'to the margin', I think I'll just manually re-number the grids as I would normally add penned numbers to allow for folding of the map. As such, my gps can still be in GDA or MGRS and the grids will be the same as those penned.

This is an 80% fix as I would still prefer MM on the PC to push the latitude details 'to the margin'. This is just one of those times when one has to be compatible with partial incompatibility.

Not knowing your output, can you print to PDF? And would that be editable?
Then do a global change of coordinate value. Obviously more steps but if you're going to manually change or add it anyway then may be a simple approach .
That also assumes you have ability to edit PDF.
Maps can be tedious.

Has MM any comment? As mentioned previously they weren't much help when I asked questions.

Good idea, but I already tried such avenues. It's not possible to save as any type of file (that I can tell).

Can you print from Memory Map? If so then try CutePDF then use a pdf editor to edit the grids

That is certainly a viable option. The PDF files can then be added to in PowerPoint or the likes. It's also possible to save as an XPS file.

Also, I have noticed that Memory Map changes the spacing of grid lines depending on the print size. Sometimes they are 1km apart, at other times they are 5km or 10km apart (with little marks to subdivide), and I'm talking about 1:25K to 1:50K scales. I am surprised they do not default to 1km or have the option to specify the spacing. Here again I will be wanting to either digitally or manually add to the Memory Map product.

wander wrote:In Australian you need to be using GDA94 (WGS84) or AGD66 depending on your paper map. Anything else is an added complication (ie a waste of time ).

Having used GDA94 (WGS84) and AGD66, IMO they work fine. I also think that the less complicated a GPS is built, the less time we spend on learning how to drive it. Hence, the less battery is consumed.

the less time we spend on learning how to drive

And the more time we have to wander and eat chocolate.

Somewhat off topic so feel free not to answer, but are MM topo raster or vector?

Raster maps.