Next virtual trek

I mentioned in yesterday’s post that I had completed my virtual trek of the Camino de Santiago. That is, I take mileage I accumulate on my treadmill in the basement and convert it to locations along the Camino. Google Maps and Streetviews then provide a good “look” at the route.

Why do I do this? First, I want to actually learn as much as I can about walking the Camino and my relatively low daily distances on the treadmill are easy to follow on Google Maps, also allowing me to find restaurants and albergues along the Camino and study their photos and menus to learn more about food, or generally something about what walking the Camino would be like. Second, using a treadmill is boring so I need some sort of incentive – knowing I’m just a short distance, along the route of my virtual trek, to a particular POI (Point of Interest) on a map gives me motivation to do a bit more on the treadmill.

So now that I’ve “finished” the Camino what do I do?

Now I put “finished” in quotes because the data I have for the Camino’s route (and thus distances along the route) is somewhat uncertain. I found a Google Earth GPS track of the Camino and used that for while, but whoever set that up didn’t renew their Google license (for embedded maps in webpages) and it failed. So I found another route. And guess what, they’re not the same.

There’s an old joke that a man who has just one watch “knows” what time it is, but a man with two watches isn’t sure, i.e. different sources of data almost always disagree. Also, until my latest exercise I didn’t try to get distances along the Camino directly from the GPS data but instead from a table I found on the Net. I did enough analysis to confirm that table seemed relatively accurate and so used that data to declare I had “finished” the Camino.

But two new items for me. While I had learned that “Camino” itself is a vague term (there are many routes of the Camino) I didn’t realize that the Camino Frances (the most popular route) doesn’t actually start in Saint-Jean-Pied-de-Port; that’s just the most popular starting point resulting in about an 800km walk. Instead that particular Camino really can start various places in France, but most commonly in Le Puy-en-Velay France (and then that segment goes by the name, Via Podiensis). Adding that segment (and also going past Santiago to Fisterra) turns the walk into a 1000 mile trek, not just the <500 miles of the conventional route.

So now I have an obvious extension to the Camino to use as my new virtual trek, the entire 1000 mile distance which will give me something to do on my treadmill for another year. So that gives me a new project, figure out the distances along the Via Podiensis. Right away (and I’ll describe this in more detail in a followon post) I found several GPS tracks but all of those have some “issues” as to figuring out distances and milestone waypoints. I also found, at a website that does escorted walks, a table of distances between the 34 overnight stops they make. But that route is: a) not exactly the detailed route of the Via Podiensis, and, b) the distances are round numbers whose sum of all the segments is about 80km less than various sources claim is the total distance.

Now people actually walking the Via Podiensis could care less about all this; they’ll find the route (possibly with some misdirection) and get to their destination. But I need as accurate as I can create route and table of distances to do my conversion from miles on the treadmill to locations in France.  And so that’s what I’m working on now and will report in a short while.

Fortunately I have plotted about the first 40km and as I’m now only (on cumulative treadmill distances) about 2km past Santiago I can restart my virtual trek for at least a couple of weeks while I figure the rest out from the multiple sources I have (and perhaps even more I might find).

Now how do I do this?

I have a long history with GPS and GPS tracks and I’ll bore you, Dear Reader (and record for myself) some details.

I first learned about GPS when I was working at a small startup in Silicon Valley and one of the engineers was recruited to go work at a new startup, Trimble. I’d never heard of this (or GPS) but learned an ex-HPer, named Trimble, had started the company and was recruiting colleagues he’d known at HP (now in the diaspora of former HP employees populating all the other startups). At that time GPS was a military technology and had a hugely expensive system (in nuclear submarines) but Trimble believed this could be re-engineered for a consumer (albeit only professionals) technology. Later, in another company I used to ride my bike to work and I often noticed people with huge backpacks and an attached 6′ long stick with electronics  on top. I didn’t know it at the time but these engineers were testing the early Trimble prototypes.

So fast forward about a decade and when I first moved to Nebraska I was going crazy in the winters (having been spoiled by California) and so just set out driving south, eventually ending up in Big Bend National Park. Driving solo and trying to read a paper map was nearly impossible so I was in the market for a better alternative. A bit of research revealed that GPSr (the ‘r’ is for ‘receiver’) had truly been reduced to consumer (affordable) level and so I bought my first laptop and the DeLorme GPSr and its software. The world of automated navigation was opened to me.

While the laptop worked fine in the car (I had to also discover “inverters”, then uncommon to power the laptop) but was useless for walking. That led me to discover handheld GPSr’s, in particular the early Garmin eTrek models which I bought at the original Cabellas (in Sydney Nebraska) and used for the first time hiking in the Bighorn Mountains in Wyoming, learning an important first lesson, use the GPSr to record the location of your car so you can get back to it.

All this led me to the world of geodashing, one of the various geo-xxx “sports” in the earliest days of consumer GPS where they were still rare and so enthusiasts would find a way to make a game of using a GPS. Over time I learned more about mapping and especially the early satphotos to use to study a place one might go, where despite roads being shown on the electronic maps (the data was crummy back then) might not really exist. Over the years I got better and better at using these tools, which eventually led me to my first “virtual” trek.

Now raw GPS tracks are usually pretty messy data. For instance, here’s a set of tracks, made over multiple days (since time affects GPS accuracy) of a corner near my house.

or even this set of tracks including the driveway of my house (the red lines are actual paths of the streets as taken from a surveyed map) – note all the scatter in the data, this will come up as an issue in my next post.

Each GPS has various options for recording data and as you can see in this image (I recorded the maximum data) there is a lot of variability. IOW, early on, with my own experiments I came to look at GPS tracks with a bit of skepticism. So tracks I found on the Net I know are not quite right.

So with all this practice and knowledge I set out to create my first virtual trek, the Pacific Crest Trail (which, btw, I did “finish”, as in do the necessary distance on my treadmill). This was years ago and I don’t remember the details but I remember writing my own code to convert the KML (Google Earth) file I’d found into Delorme “route” info. I quickly learned that Delorme couldn’t handle the entire PCT as a single “route” so I had to break it in pieces.

BUT, the key thing was Delorme could convert the waypoints (fortunately closely spaced) to distances. Given the PCT doesn’t follow any “roads” the routing within Delorme itself was useless, but I found a way to get distances from the GPS track and from that I could then convert my cumulative treadmill distances to location. Of course I used Google Earth to “view” the PCT, but: a) at that time Google hadn’t done Streetview yet, and, b) the PCT is a wilderness trail that doesn’t follow any “roads” in the Delorme database. But Delorme was designed to use (the Topo) version for people doing outdoor recreations and thus was happy to have routes that didn’t follow any known paths in their database and still get distances.

So all of this led to where I am now. I hoped to repeat the process but knowing: a) there is a lot more and newer information, mostly from Google, and, b) Delorme only has detailed maps for the USA. So now I had to find a new way to replicate the process I used for the PCT and apply it to the Via Podiensis.

And I’ll end this post with this, to be continued with the explanation of the process I am discovering (still having to experiment some) for Via Podiensis which eventually means I’ll have what I need: a fairly precise table of distances (at roughly 10km intervals) that actually follows the roads, paths and even off-road trails (not known to Google, but I can guess some). It’s a tedious process but for me, with my weird obsessions, an interesting exercise in itself with the ultimate outcome (still a hope but fairly sure I can do it) to create what I need for another ~750km of virtual trek.

 

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