Bushwalking & Geek 14 Apr 2008 03:45 pm
Bushwalking - Sherbrooke Forest
This weekend I went for a walk in the Sherbrooke Forest, part of the Dandenong Ranges National Park. I followed a track described in the book 150 Walks in Victoria, by Tyrone Thomas and Andrew Close, and everything went fairly well.
To get to the track, I took the train to Belgrave and, from the station, walked approximately 1km (uphill) on Old Monbulk Road to the gates of the park. From there, I followed the trail in a clockwise direction, first north up to Grant’s Picnic Grounds (close to Monbulk Rd and “infested” with cockatoos trying to get food from the families eating there), then approximately south-east on Lyrebird Walk, continuing south on Neumann Track then south, and later west, on Paddy’s Track leading to an apparently unnamed track going west from a clearing known as Jack the Miners back to the starting point. A map of this path is here, including some pictures I took on the way (more pictures at my Flickr page).
The length of the path is around 6.3km, with some significant vertical movement as well; the first leg of the track leads steadily up, while the southward leg goes a bit up and then steeply down. The final few hundred metres go steeply up and reduced my average speed significantly…
This was also the first “field test” of the GPS unit I bought (and mentioned here), a Magellan eXplorist 400. It did very well (as the map linked to above shows), but I did find a few things out:
- the “trip odometer”, which should tell me how far I’ve moved, is either very inaccurate or using the wrong units; at the end of the track it was showing “4.0km”, while the recorded route was actually 6.31km long (which equals 3.92 miles…); this is definitely not good
- when you turn the device on, it takes around 60 seconds to lock to the satellites and get your initial position; that’s normal and more or less unavoidable because of the way the satellites transmit data; however, if you are moving — however slowly —, it seems the device won’t reliably find the satellites after any amount of time; this is not very good, but I can live with that (after it finds your initial position, it can be moved with no problems; also, being inside a backpack is not a problem)
- it won’t find the satellites from inside a train; I’m honestly curious about how it will perform inside a car
- marking positions is a very easy and quick process, but “typing” using that on-screen keyboard and mini-joystick is a pain
on 15 Apr 2008 at 2:35 am 1.Cassio said …
I think there’s two possible explanations for the “trip odometer issue”:
1. As you said, it can be using the wrong unit. You can try it by walking around a park of known park
2. Maybe it’s not taking your vertical movement into account. You can try it by measuring a trip from the top of a building to the ground. If it really doesn’t work, you can try it with an acceleration of 9.8m/s^2