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Re: Most reliable mileage estimates?

Hello Brennen

I am quite new to this too but am just experienced enough to have 1: been in your position and found some answers(fyi my husband and I recorded 18.6 km on our inaugural TGO day from Dornie to just past FOG in 2019) and 2: to have noted that as far as the message board goes, "someone will be along soon"! You will likely have plenty of good advice in no time.

In the meantime, I will share a couple of thoughts and say good luck to you in 2021:
Though access can sometimes be limited due to Google platform constraints Wheres The Path at is a handy free (though accepting donations!) tool for mapping and calculating distances and rough ascent/descent figures. And GoogleEarth is just plain cool.
Also, I have found it to be a good value to invest in mapping software, as maps may be printed, distances and ascents calculated and many many joyful hours wasted. Personally I am sweet on Routebuddy. I believe MemoryMap and Anquet remain popular as well.
Additionally--this board has been around for a looong time. It is often worth checking the archives to determine if there has been a previous discussion on the topic you are interested in. You won't get the social, but it can help narrow down the question

Re: Most reliable mileage estimates?

Hi Brennen and welcome to the message board.

You'll find that the measuring tools on all of the mapping software should be accurate for distances. I'm only familiar with a few but I'd doubt that there'll be much significant difference between them. You can plot your course with accuracy and the minimum of fuss and be confident in the result. Prior to such digital measures, Challengers have used manual devices with a wheel and a scale which they ran over the map; they tended to be rather less precise. I believe that there are some technology averse individuals who still rely on a length of string, not a method I'd recommend.

So far, so uncontroversial, but when you look at measuring ascent, the water becomes murky. Digital measures will give you a figure but it's much less likely to be an accurate one. Curiously, the problem isn't with the software; if used with precision, the tool will be fine. Unfortunately, human error creeps in, as you have to plot a serious of waypoints and if those aren't placed with some accuracy, small errors rapidly multiply. It's fairly normal for an ascent calculation using a digital measure to be 15-20% in excess of the true figure and when the contours on the map are complex I've seen errors which can be much higher. Annoying though it may be, i'd recommend laborious contour counting for assessment of ascent.

Hope that helps. Good luck for next year.


Re: Most reliable mileage estimates?

You say that you haven't got your OS maps yet but are you aware that high resolution OS maps, with the ability to create and save routes with distance and elevation profiles are on the OS website, for free?

Example :

Like any mapping software, the accuracy of distance and elevation change calculations will depend heavily on how many data points you create. As far as I know they all just assume a straight line between two waypoints. There are alternative methods used in surveying, I spent a career surveying wellbore in the oil and gas industry, which assume a curve between waypoints but I don't think such models are used by simple mapping software. It is very easy to demonstrate, create a route between two endpoints over hilly ground and then fill in more and more waypoints and see how the distance and height change increase drastically.

Re: Most reliable mileage estimates?

If you are plotting a route using the OS website it will mould it to marked paths in national park areas (for example the Cairngorms). You need to be using to OS map view in 1:25000. I have found this very useful and it improves accuracy hugely.

Re: Most reliable mileage estimates?

I can't say that I have noticed that Lindsay, in fact if you look at the example I've enclosed you can see where I have deliberately drawn a return route a few metres off the path parallel to the outward route. That's bang in the middle of CNP.

Re: Most reliable mileage estimates?

It definitely works, however you look like you are in standard view, rather than OS leisure map view - you can change it at the bottom with the icon that looks like a stack of paper.

I would add a screenshot to demonstrate, but I can't work out how to add pictures to a post.

Re: Most reliable mileage estimates?

Ah! I see, you're one of those posh folks who pay for subscription. Personally I just use the free version which serves my needs and I buy paper maps for areas of particular interest with the mobile app option allowing me to store my paper maps on my phone for offline use. The standard option is a remarkable free resource.

Re: Most reliable mileage estimates?

Hi Brennen, and a big welcome to the Challenge.
I have used Viewranger for the last 4 years and I am very satisfied with it. You design a route on the computer by placing dots on the map where you intend to walk. I have found that as you only place a limited amount of dots when planning the route that it slightly underestimates the distance. So when submitting my route sheet I have learned to add about 10 % to my estimated distance for the day and that is usually very close to what I end up walking.
Unfortunately I wont be doing the challenge this year, but might bump into you in the hills, for all that.
Best of luck, you will love it.

Best Regards also to the rest of the TGO family.

Re: Most reliable mileage estimates?

Hi All,

Thanks for the helpful replies! I am an old fogey used to measuring out lines on a map, and Basecamp was my first foray into digital mapping. Convenient to use, but it gives me very different distances than other tools.

I didn't realize the OS website could be used for planning routes. I just tried it out, and it's great, so I'll probably start there.

Thanks again!