Tag Archives: GPS

Not so Shonky Maps for the GPS

I’ve been playing with the free Shonkymaps for the new GPS. Basically it goes like this: the GPS only comes with very basic maps.  Just the ‘big picture’ stuff, no street names, mountain names, height information (topographic data) etc.

You can buy commercial maps and load them into your GPS. Actually you load sections of them in, for the area of interest.

…or some kind souls create ones for them – and us – to use.

On example being ShonkyMaps (the name is the users account name, not a reflection on the quality; “shonky” being Austrlaian slang for something a bit dodgy or not quite legal or legitimate.)   The best way to describe it is from the author themselves:

Shonkymaps are a set of unofficial Garmin compatible topographic maps that cover the whole of Australia.  The author was not satisfied with the Garmin base map that came with the Garmin gps, and at the time there were no other topographic products either official or unofficial.  He created his own set of downloadable topographic maps as a hobby / labour of love.

That quote – and the maps themselves – are from the Shonkymaps web site. I won’t go into detail on how to get the to work (it was VERY easy), but work they do.

Something went astray with my usage on the recent Mt Macedon walk, the map layer(?) seemed to vanish, but I’ll look into that. I could have pushed the wrong button or clicked on the wrong menu. The waypoints and log/track were still visible. Strange.

Anyway hats off to Shonky for a great job. The amount of detail is fantastic.

GPS working very well for bush logging, err bush walk logging.

Took the still fairly new Garmin GPS out for a walk yesterday. I started work just after I got it, so have hardly had time to get to know all the cool features it has. So with an unusually warm day forecast for this time of year, it was back to tackle Mount Macedon again.

The main reason I got it was for logging, that is not for telling me HOW to get somewhere, but to actually RECORD where I’ve been.  Later on I can take these GPS logs and do a number of interesting things with them, including:

  • Show them on a computer map
  • View the log (and hence bush walk) on a 3D ‘map’ in Google Earth

Both of which – and photos of the walk – are shown at my Picasaweb album page.

The Mt Macedon walk is very enjoyable and a bit of a challenge. I guess I am somewhat fitter than when I tried it earlier this year, as I found the first bit – a zig zag climb of some 1.5km – much easier this time around.  The weather played its part too, it was a sunny, windy day, but the trees protected me from the worst of it. I really felt how strong the wind was at the summit area; on Camels Hump. It was actually getting dangerous being on the exposed rocks, with large drops all around, and the gusts pushing me towards the edge!

Organ Pipes National Park walk and GPS trial

Was a sunny but cool day today, so decided to take the new GPS out for a spin and get some exercise at the same time. The Organ Pipes is a natural rock formation quite close to Melbourne; the exit is literally off the Calder Freeway near Keilor.  They were formed millions of years ago when lava cooled slowly and cracked into quite regular columns. Erosion exposed them and they are now on the side of a hill on a river bend. And yes, they really do look like organ pipes.

Before I left home I knew there were at least a few interesting things to see whilst visiting this Park; the Pipes themselves plus another interesting formation called the Rosette Rock. I wanted to get their exact GPS locations (latitude and longitude) and put them into the GPS before I left. I’m still searching for a list on the web of such ‘waypoints’, but no luck so far. So went to Google Earth, zoomed in…and using some of the external data (layers) was easily able to find the Pipes and the Rock.

I used gpsbabel to convert their Google Earth co-ordinates to Garmin format, uploaded to the GPS and ta da, they both appeared in the GPS and on its Map.

Anyway I did this very pleasant walk just fine and the pre-loaded values were very accurate; for example the GPS beeped – a proximity alert – when I stopped at the Organ Pipes viewing area itself.

I also logged the walk in the GPS so it could be seen in 3D back in Google Earth; which confirmed what my legs had told me: down a steep hill, along a flat river valley and back up the steep hill.

One final comment on this National Park. When I first visited it in the early 1970s it was very barren. Just bare grassy hills and weeds. Over the following 30+ years a group of volunteers have done a sterling job clearing out the weeds and planting native trees and shrubs. The result is nothing sort of amazing as the ‘before’ photos ot the place show. Barren to living bush again.  Well done! 

GPS : Open Source Maps

Having finally got a full GPS at last, it was time to get some maps. The unit very quickly found exactly where it was on Earth ; and I mean quickly. But the basic map that came with it, only said it was near Melbourne. Nothing like street level.  It could tell me my latitude and longitude as well as log it when I went for a walk around the block. In fact I did this, converted it to Google Earth format and was able to see how accurate it was, particularly compared to the GPS in the HTC mobile phone.

Anyway time for some maps. I do not want Turn by Turn street directions. In fact the GPS is set to be in “off road” map mode which means just get me from Point A to Point B, don’t worry about keeping me on the Roads. So it’s more for bushwalking.

Of course there are commercial maps out there and I may very well end up buying them. However I soon discovered the free, open-source type maps; the Open Street Map (OSM). Most GPS, including mine, cannot directly import the OSM data.  So here’s how I got it to work:

  • You can run your own extractions and conversions. However some good people regularly extract and convert (OSM) data for given States and GPS.
  • I grabbed their Victoria one (VIC.img.zip).  Unzipped it (VIC.img)
  • My GPS cannot directly import these (older?) format files, so I grabbed the free version of sendmap20 and installed it
  • The GPS only stores maps on a microSD card, so installed that
  • Ran sendmap20.exe and dragged VIC.img onto it…then copied it to the GPS unit

Worked first time, now have nearly 6 MB map of Victoria.  It shows a fair bit of data.  I loaded up the log I did yesterday (the walk around the block) and it showed the streets where I had walked, but didn’t name them all. However, I’m very happy with it so far.  Will be interesting to take it off on a real bushwalk and see how it goes.

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Got a GPS (at last)

Take 3 on this one. My first GPS was some years ago, but it wouldn’t work with rechargeable batteries (despite the store saying it would). But they were cool about it and gave me a full refund. Particularly when they themselves couldn’t even fit the rechargeable’s inside the unit.

The second was the ‘bonus’ GPS that’s part of my new HTC mobile phone. It works okay, but eats the battery. It’s quite accurate. But the battery stuff was a killer for ne. As I said, it was a bonus in the phone and the phone is cheap, so no complaints here.

As I’m doing more bushwalking I decided to get a dedicated GPS unit. I plan to use it not for assisting me get from Wombat Creek to the top of Mount Howitt, but for the logging (recording) of this trip. I still use bushwalking books and maps, but it’s great to have the GPS log where you went. Then you can load it into Google Earth etc and see it in 3D.

Later on I’ll probably move to route planning. I also tried my first Geocaching yesterday.  Basically it’s a treasure-hunt using your GPS. You go to a web site, type in your postcode and nearby Caches are shown. These are GPS latitude and longitude co-ordinates.  And off you go to find the cache.  In fact the first one was like 1km from my house, but had the sea between me and it. However I didn’t look closely at what the GPS unit was telling me to do. I ended up on a thin, long (artificial) point of land that stretched about 1km out into the bay. But I wasn’t used to the GPS and picked the wrong point, so when I got out to the end it was telling me to go 400 metres north. Which was across to water to yet another thin, long point…

I think part of the problem was moving the GPS from horizontal up to vertical and back. Moving it up to vertical makes the GoTo/Compass function (“walk THAT way”) obviously get confused.

Anyway it’s a Garmin eTrex Vista HCx model, which I purchased new from the USA.  Even with the postage it was much cheaper than buying it here. And it took only 5 days to get here!

First GPS logging with new phone – NMEA sentence

Been trying out some GPS logging software with the new HTC p3600i PDA-Phone. This unit has a built-in GPS, but the supplied software was way over-kill for me. All colour maps and turn-here voice directions. I just want a simple application to tell me where I am as a few lines of text, plus log it for later use. Specifically to convert to Google Earth format and look at my bush-walk in 3D.

The software I found produces the generic NMEA format messages. Here’s a sample:

$GPRMC,001902.0,A,3751.782669,S,14454.073719,E,1.1,301.2,160508,,,A*7C

A number of sites have this format explained, but I can pretty much decode some elements right off the bat:

001902 is the time in UTC/GMT 00:19:02 with 160508 being the UTC/GMT date (hence Melbourne time/date of +10 hours so 10:19am and 2 seconds on 16th May 2008) Correct!

3751.782..,S etc jumps out at me as very much Melbourne’s (well, Williamstown’s) Latitude and S = South. It’s actually 37 degrees etc, so this must be a decimal version

14454…E is our Longitude, East.

Easy!