OSM maps for Garmin GPS

[Rolv]

With due respect, "the time it takes for the position to be related to the satellite, the satellite to process the signal then correlate position and send it back to earth" This statement is technically incorrect, the earth GPS unit doesn't send any signals to the satellites. The the GPS earth units only receive and process the received signals.

[bernieq]

A GPS is never 100% accurate, and cannot be. At best, it is a very good guide! Dilution of Signal — the time it takes for the position to be related to the satellite, the satellite to process the signal then correlate position and send it back to earth means there are variations in accuracy (often BIG variations), ...

Hi Biggles, either you're confused about how a GPS works or I'm not understanding you. A GPS doesn’t communicate with satellites - it is a receiver only, not a transmitter. Have a look at https://spaceplace.nasa.gov/gps/en/

Dilution of Signal? Are you referring to (geometric) dilution of position? which is concerned with the (very small) variances in calculated position that can occur as a result of the positions of the 4 (or more) satellites needed for the GPS to calculate it's position. eg if all satellites are well west of the GPS vs evenly distributed around the GPS (eg N, E, W & overhead).

What does 100% accurate mean? We're bushwalkers - how accurate do you need? To the nearest few metres is more than sufficient & a GPS delivers that in all but extreme locations (in narrow gorges, bottom of cliffs etc).

Edit : sorry, rolv, didn't see your post.

[andrewp]

Hi guys,

This discussion has gone off-topic. This thread is for OSM maps for Garmin GPS. Please strart, or use, anotger thread for general GPS discussion.

Thanks
Andrew

[andrewp]

Hi all,

New version of all maps with current OSM data. No other changes.

[andrewp]

By the way the link to the maps is on the first post, but just to repeat it:

http://tiny.cc/osm-maps

Last edited by andrewp on Sun 30 Jul, 2023 3:05 pm, edited 1 time in total.

[peregrinator]

By the way the link to the maps is on the first post, but just to repeat it:

http://tiny.cc/osm-maps.

Andrew, link not working for me. 404 Error. So I assume the issue is that it is a http URL, not https.

But nevertheless, I thank of course, for providing the maps.

[tastrax]

http://tiny.cc/osm-maps

dropped the period at the end

[andrewp]

Thanks tastrax.

[Graham17]

Thanks !

[GPSGuided]

By the way the link to the maps is on the first post, but just to repeat it:

http://tiny.cc/osm-maps

Brilliant and thank you!

[andrewp]

Hi all,

Another new version of all maps with current OSM data. No other changes.

[Biggles]

Thanks Andrew.
Downloaded VicMap and OSM-maps from interwebby; both now on GPSMap64s.

[tom_brennan]

Thanks as usual for your great work Andrew!
cheers

[andrewp]

Hi all,

Another new version.
Rebuilt NSW, NT, QLD, SA, TAS, VIC, WA with new OSM data. Changes for Walls of Jerusalem (TAS).
Re-instated add-pois-to-areas for any polygons with tourism tags, mainly for huts and camps shown as a polygon, rather than a point.

Cheers
Andrew

[andrewp]

Hi all,

Another new version.
Rebuilt NSW, NT, QLD, SA, TAS, VIC, WA with new OSM data.

Cheers
Andrew

[bernieq]

Thanks, Andrew - much appreciated, as always.

[Off-track]

Thanks Andrew. The combination of clearly displayed 10m contours and waterways plus OSM data is very useful for hikers.

These img maps work well in BaseCamp (which I use for route planning). Just place them in a USB drive (in a folder named Garmin) or use the virtual drive method described by JaVaWa at https://www.javawa.nl/virtualdevice.html.

They are probably equally good in a Garmin GPSr, but smartphones are now so good that I have not used my 60Cx for years. Oruxmaps on my phone does not do such a good job of displaying these img maps, even after tweaking OM settings under Map>Garmin. In OM, it is probably better to alternate between geopdf or WM(T)S maps from the State government sites and OSM maps from OpenAndro at https://www.openandromaps.org/en. The WM(T)S mosaic is lower in resolution, but easier near mapsheet edges (because OM can only load one geopdf at a time). OSM often has better tracks/footpads but take care as it also has errors. The government sites often include other useful topographic data. It is great to be able to flick back and forth between maps to build the best mental picture.

[Warin]

OSM maps from OpenAndro at https://www.openandromaps.org/en. The WM(T)S mosaic is lower in resolution, but easier near mapsheet edges (because OM can only load one geopdf at a time). OSM often has better tracks/footpads but take care as it also has errors.

OSM data can be corrected by anyone.
I like OSMand because the maps are updated monthly, so any corrected errors are gone in a month and any updated data is also there in a month.
OpenAndro maps update 4-5 times per year...

[Graham17]

For OSM & other mapping buffs in TAS, Listmap Tasmania now has georeffed tiffs for historical air photos
Its a good way to check out old places for uo to 75 odd years ago. Thanks Listmap peeps !
https://nre.tas.gov.au/land-tasmania/ae ... hotography

[Off-track]

These .img maps highlight the interesting problem that different states use different representations for map elements such as intermittent vs. perennial watercourses.
The difference is striking if one looks in the vicinity of adjoining Lamington NP (QLD) and Limpinwood NR (NSW).

Cartographers do not always capture what is in the field, and even the states seem to change the classification and/or definition of these things over time or in different map products.
Current Qtopo maps (and the .img map) show the Albert R as intermittent way upstream of the parts that most hikers would consider as perennial.
On the other hand, the .img map does not seem to follow the current spatial.nsw method of distinguishing these hydro-line types. (Except during heavy wet periods, hikers would need to follow some of the .img map solid/thick blue lines well downstream to find a trickle of water.)

I notice that the usual OSM topo maps often do a closer match to on-the-ground reality for waterways (not to mention consistency across state borders); but it is a bit uneven. The usual OSM topo maps have poorer contours than these .img maps.
Garmin Topo Australia (v5 in my installation) also does a good job of distinguishing watercourses that are perennial vs intermittent in a "normal" year.

This is a reasonably complex issue, especially once one gets to legal ramifications https://www.researchgate.net/publication/297442802_Up_the_creek_What_is_wrong_with_the_definition_of_a_river_in_New_South_Wales.

[Warin]

I notice that the usual OSM topo maps often do a closer match to on-the-ground reality for waterways (not to mention consistency across state borders); but it is a bit uneven.

Within OSM there is some different interpretations of 'seasonal' and 'intermittent'... And I tried to introduce 'ephemeral'. Renders (map makers) don't usually distinguish between 'seasonal' and 'intermittent' so the contributors interpretations don't actually go anywhere.

Of course there are entries from overseas who are not familiar with Oz and put perennial water where that should be intermittent .. I think I have all the major 'lakes' now correctly mapped as intermittent, though I'd rather have some as ephemeral. Your free to make corrections by simply registering on OSM.

[andrewp]

I've just posted new versions of all maps. No major changes, just using latest OSM and VicMap data.

[andrewp]

I notice that the usual OSM topo maps often do a closer match to on-the-ground reality for waterways (not to mention consistency across state borders); but it is a bit uneven.

My img files use the state hydro data for NSW, VIC, TAS, QLD and SA (only part of). The others (i.e. WA and NT) use osm data for hydro. It's often quite tricky to interpret the states use of intermittent, and with osm it is up to the contributor.

[Graham17]

new versions.. cheers thanks

[andrewp]

Hi all,

I've just posted a new version of VIC. There was a problem with the coast line on the version from 1/8/2024. If you downloaded it you need to download it again and replace it with this new version.

Sorry about that.

[andrewp]

Hi all,

Have replaced WA with a new version that isn't just contours! Had a hiccup when extracting stuff from OSM. If you downloaded the 1st Aug version you should download this one instead.

[tom_brennan]

Thanks again for all your work Andrew - long term maintenance of a project like this is often a thankless task. Much appreciated.

[marcelus]

How to use these OSM map files with eTrex handheld devices?

OP if my question is out of scope in this thread, please indicate thus and I will be happy to remove it.

My question is whether, and how, a Garmin eTrex unit can utilise these excellent maps created by Andrew.

I am not familiar with eTrex units, but they seem to be small and light and I value those attributes.
Also not familiar with the Garmin Explorer app, but from reading reviews and blogs it appears some users express frustration that they have to involve the Explorer app to manipulate maps on their eTrex, and in some circumstances it requires wifi or mobile signal to work.

Before posting, I searched this thread for comments on hardware and noted an earlier post by "trekka2019" where he was advised that, to load Andrew's maps, he could simply use a PC/tablet/phone to copy the .img files onto an SD card, then insert said card into his GpsMap64 handheld device.

That sounds ideal to me - simple, robust, no apps required, no mobile signal required, minimal failure modes.

Question is whether there are any eTrex models that will allow you to do that?

[andrewp]

Hi marcelus,

I'm assuming that you don't have an etrex.

There are instructions for downloading and installing in the file MapInfo.txt on the download page:

Download and Installation information:
======================================
Download each file individually. Do not try and download them all together, because Google Drive hangs trying to zip them all up.

When you download the files you will probably get a warning about Google unable to virus scan the file. You can safely ignore it. I think it's because the files are too large.

Copy the img files to the Garmin folder on your GPX device or micro SD card.

On your GPS the maps will probably be automatically enabled. You may want to disable the ones that you don't use to make it quicker to start the GPS. How you do this depends on your GPS model. On the ETREX 20, 30 it's under Setup/Map/Select map. You could also set up different profiles with different maps enabled.
======================================

So you can use the etrex 20/22 or 30/32 to load maps. I'm sure all the other Garmin handheld GPS work the same way. Just copy the map img files to the Garmin folder on the device or the SD card.
The etrex 10 doesn't support installing maps, but I'm not sure if that is still a product.

Please ask if you have any more questions.

[icefest]

The maps also work on garmin GPS smartwatches!

I use a fenix 6, and my partner a fenix 7!
Topo maps, waterproof and enough battery for a 3 day walk without charging.