Navigation on eBothy Blog

viewranger app update

Fri, 15 Jun 2012 00:00:00 +0000

I’ve been using the Viewranger app on and off for a while but only used it in anger yesterday on Fionn Bheinn. I turned off wifi, bluetooth and all that and turned location services off on all the apps that were requesting it apart from Viewranger and the phone battery lasted all day with the app constantly active. On first start it takes about 5mins to get a fix but that’s more to do with the phone hardware than the app and the direction indicator can be a bit dodgy. At one point on Ben Wyvis it was showing us on the summit, which was correct but the direction indicator, when pointing back along the ridge on the app, was pointing the phone off to the south of the ridge. Not ideal. But the position fixing is spot on.

the gps conundrum and the vi effect

Sun, 22 Aug 2010 00:00:00 +0000

The other day Dawn and I were trying to remember the name of a restaurant in Glasgow that we’ve been to and neither of us had the foggiest what it was. So I fired up the phone and courtesy of a Vodafone Femto Cell which gives 3G coverage in the middle of nowhere, we used Google Maps to virtually walk down Bath Street and stand outside the restaurant, noting its name and phone number. Job done. Rewind a couple of years to where I met a bloke near the summit of Beinn a’Bhuird who had a phone he kept looking at and I’m sure he had earphones dangling too. So I suspect he was using an early form of GPS, probably a Nokia as they were popular back then but strangely he had joined me on the edge of the cliffs. I was there to take a bearing where the cliff edge turned south, so I knew exactly where I was for an accurate bearing to the summit on the featureless plateau but he had a GPS and only now I’m wondering why on earth he ended up at the same spot as me. Why didn’t he navigate straight to the summit? Leaving aside such questions, I think I was witnessing the birth of smartphone based navigation. A topic much in the news these days and tipped to knock GPS units into the void. But just how accurate and reliable are GPS’s?

working out the slope angle the hard way

Sun, 06 Dec 2009 00:00:00 +0000

I was idly browsing January’s TGO, yes it’s only December but the mag is a month ahead and alongside the usual excellent content, there was an article on winter navigation. Now, as I’m heading for Winter ML assessment next winter (consolidation this winter), I took note of some points, especially the bit where it said that 6 index contours in 1cm on a 1:50,000 map is a slope angle of 30deg. That’s the most common angle for big avalanches, so it helps to be able to spot one on the map when you’re planning your day out in the winter mountains. Where does that number come from though? Well, with the rain lashing the windows and the gale rattling the slates (bit wild at the eBothy today), I thought I’d brush up some ancient maths skills to find out.

extreme extrapolation

Sun, 03 Aug 2008 00:00:00 +0000

Take a bunch of researchers, a couple of seals, one planetarium, a laser pointer and loads of spare time. Train the seals to head for Sirius and feed them each time they bump into the wall below the star. Remove the laser pointer and observe the seals head for Sirius every time. Apply Extreme Extrapolation. Seals navigate by the stars. The story is here and the paper is here.

the tao of navigation

Thu, 10 Jan 2008 00:00:00 +0000

I read a really nice article the other day by Lauren Webster about the Taoist principle of action and I thought about how this might be applied to navigating in the mountains. The principle basically states that to overcome obstacles in life, you have to be confident in your environment and your abilities. You have to believe in yourself. One of the traits of a good mountain leader is having the courage of your convictions. Many times I’ve been out in foul weather and someone has been making pronouncements on the way ahead while I have been studying the map and working out a safe descent route. More often than not, the compass shows the way that is not obvious from memory. The way down always looks obvious in the mist. It’s the route of least resistance but which can lead to a big drop or a swollen river. The wisdom of the compass is always hard for non-believers to trust.