GPS

Long Road to London

Yesterday I thought I'd take my new bike out for a spin - then I thought about going on a long bike ride. Path to LondonThen I decided to attempt to cycle into central London from home, and finally I decided to do this on the old bike as I didn't want to do anything too ambitious on the new bike until I've broken it in a bit more.

So it was, that I set out on a ride from home (on the Surrey/Hampshire border) to Central London.

I planned a route with the aid of the Surrey Cycling Maps and the Transport for London cycling maps. Both sets of maps are free. Unfortunately there was something about them which made going from one set of maps to the other tricky for me - I'd love it if the maps were downloadable as jpg so I could use them in OziExplorer - or better still, if the data were handed over to google to allow cycle routes to be planned as easily as road routes!

I worked out a rough route on the paper maps, then used the mapmyride website to store the route electronically. This was then downloaded to my Garmin GPS 60. This is not an expensive device, but it is good enough for my purposes.

Essentially, I can download a route to it, and it will tell me which way to head in order to reach the next waypoint. It doesn't know about roads, buildings, cliffs and the like - and so the directions are only as good as the route that it has been fed.

Thus it was that I set off.

I had a later start than I hoped for - and was slower than hoped for as I stopped to go to the supermarket for some sustenance (I had forgotten breakfast too!). Getting to Woking took longer than usual, but I was soon in new territory, going past Woking and was at my first major landmark. The psychological barrier of the M25.

Crossing the M25

It was really great getting to this point under my own steam - for me it is the boundary of London (it isn't really, but nothing else is that obvious).

I cycled on, through Addlestone, and onward.

Hampton Court provided my next stop. It's a lovely place to go through, open grassland (and a road, admittedly) - with deer.

The deer were quite used to the cars, and so were not too phased by someone on a bicycle. They were quite bold (for deer) - though never totally unwary.

Deer at Hampton Court

I crossed the River Thames several times. Having crossed near Hampton Court, I went south of the river again at Teddington Lock. Nice place.

I had chosen to go through Richmond Park as well. This is a lovely place to go through - the paths are smooth, traffic-free and there are herds of deer. The deer are different to Hampton Court - and again, they are relatively used to people. This was a much larger group, and they formed a protective ring around their youngsters.

As I watched and waited, they all moved across the road - that was good to see, it had echoes of 'mass migration' about it, but in miniature!

From Richmond, I carried on into central London, thanks to the cycle maps I had very few busy roads to travel. I arrived at Buckingham Palace, and being a Sunday the mall was closed to cars, so I had a lovely cycle down toward wesminster. There was traffic over Westminster Bridge, and then I was at Waterloo, some 69km after I set out.

I made it to London!

It was my longest cycle by far so far. I may have cycled further 'back in the day' - but then, I never kept track of this sort of thing when younger (I did get lost many times though - though the only time I had to be rescued was when I went for a walk, and I went so far the soles of my shoes caved in!)

My normal commute is about 18km each way, so this represented nearly a fourfold increase on my longest ride (or doubling of my daily ride). I did arrive at Waterloo wondering if I shouldn't just cycle back home - but felt like this was asking for trouble... however, I think I could have done it. Maybe another day.

My high spot at the end of the ride was cycling down the mall - that was my 'finish'. Getting to Waterloo was anti-climactic. I'd just done a big ride, and I wanted a finish line - dammit, I wanted a medal for finishing! If I'd have known that Waterloo would've felt like 'the way home after finishing' instead of 'finishing', I'd have done a lap of honour on the Mall!

Anyhow, that was my big ride - about 43 miles. Not bad, I could have gone further, but I was being careful, I didn't know how I'd react the next day. As it is, I've a bit of soreness in my thighs, and that's about it. I did a few stretches on the train to try and prevent leg muscles cramping up.

Key Details: Date: 2008-06-29 Distance: 69.8 km. Speed: 19.24 / 47.33 km/hr (avg/max) Duration: 03:37 (ride time, stopping for the M25, level crossings, deer and supermarkets not included)

GeoHashing

Via xkcd I learned of a new idea called 'Geohashing' geohashing

Essentially the idea is that based on some seed data, some complicated sums are done to give a location.

People get to that location for a meetup.

A map tool is available which does the sums for you. You set the date, click your area and it gives you a location.

Due to problems with the seed data (US stock market) and time zones a new rule has been introduced today for people east of 30 degrees west. This is taken care of automatically by the map tool. There are several pieces of code for implementing this - though most have yet to be updated to reflect the 30W rule.

The idea is that the seed data is processed using an algorithm called md5. This algorithm produces a 'hash' of the data. it is difficult to find alternate data which produces the same hash. A small change in the data produces a big change in the hash.

The idea of a hash is a way of producing a 'fingerprint' of a file. I.e. I could send you a file, but how would you know it hadn't been tampered with? Well, I could phone you, you could recognise me and I could read you the hash of that file (which you can then generate and check).

A hash can also be used as a zero knowledge proof. I.e. I wanted to prove to you that I had discovered some fact. I might not want you to know the fact (yet). For example, I might know the first line of the 'Times' editorial for next saturday. I could generate a hash of that line and give it to you - when the paper is published that information can be checked.

In this case, the md5 algorithm is used to give a reasonable pseudo-randomisation of one number into another. It's just a bit of fun.

I've not gone to a geohash event myself - but I like the concept.

Moleskine GPS

I recently wrote a piece for moleskinerie. It has been published today. It's reproduced below.


I like gadgets. It's a weakness. If it has buttons, or even better, lights - then I'm hooked.

Travelbug on moleskine

I've wanted a GPS for some time, mostly for the geek value - it's true. So, I began to look for ways to justify the cost, and I discovered Geocaching. Geocaching started just a few years ago (when Bill Clinton switched off the 'Selective Availability' which meant that GPS systems had accuracy of a few hundred metres), and has since grown into a worldwide sport. With a good GPS signal, your location on Earth can be known to within a few metres.

In the simplest form, someone hides a geocache. Someone else finds them. The caches could be hidden out in the countryside, or hidden (discretely) in a city centre. Just the other day I went into London and found 13 caches, some in very well trafficked areas.

Caches can be more complex, in a multistage cache a series of clues need to be solved to discover the final location - and in a mystery cache research may be needed before you even walk out of the door!

Examples:

Simple Cache
GCGBGB : Last Delivery
MultiStage
GCVKR6 The Elvetham Heath Reserve
Mystery
'X' marks the spot

When a cache is found, the finder writes in the log to claim a visit, replaces the cache and moves on. As caches are often (but not always) placed in interesting spots, I\'ve found that since starting to cache I've discovered places locally that I never knew existed. Geocaching provides me with a 'purpose' to a walk - a definite target, and it helps to keep each walk unique.

Where do the moleskines come in? When I started I decided to keep a personal log. In the log I record the cache name, coordinates, and any other piece of information. This may be a hint to the location, so that I can help anyone who gets stuck that follows, it might be a note about the weather. When I get home I log my finds on the geocaching website.

Geocaching website:
Geocaching.com

Another feature of geocaching is the gift. Many caches contain 'goodies' - these are usually small items. The rule of thumb is that for everything taken out, something else goes in. One common type of item is the travelbug. A travelbug is a trackable item with a unique serial number. When at a computer, the item can be logged independently and it can be tracked in it's travels. The number should not be revealed online, as it is evidence that the bug has been found. Travelbugs should be placed in a new cache within 2 weeks, and not taken unless this can be done.

Of course, if I take anything from a cache, this is recorded in my notes. I make special care to record the ID number on a travelbug, so that I can put it into a new cache the same day if I wish. (The danger here is that someone else may find it and log it before I do - this messes up the chronology of the bug, if late in the day, I don't worry about this. If early in the day I attach a note to say I'll be logging >the find by the end of (date), and for the finder not to log themselves until after that time  )

I wanted to launch a travelbug (I now have seven out in the wilds) - and my first travelbug? A moleskine, my own 'wandering art project'.

I launched it by putting it in a newly placed local cache, after preparing it well. Inside the cover are instructions about what the travelbug is, and about it's mission.

The Silent Sentry 1 Geocache

The bug itself can be tracked here:
Track the bug

The idea is that each finder makes their own piece of art in the book, and scans it, before placing it in a new cache (hopefully well protected from moisture!)

The future? I've found 65 caches in total, and am heading for 100. I'm currently looking into paperless caching (so there is less printing out before I head off on a walk, I could take the gps and pda, and off I go). Even if I do make the leap to paperless caching, my moleskine log will stay with me to record the results of my finds.

Related links:
Link for 'Geocaching'
Geocaching in the UK

GPS and Michelangelo

Yesterday I acquired a GPS from Amazon, and I decided to go into London. I wanted to see the Michelangelo exhibition, and test the GPS at the same time. I walked around home a bit to check all was well, and then I headed off for the train. Unfortunately there is no way to get the GPS signals in the train, and so as soon as I left Waterloo station I switched the thing on and found my satellites.

I started to walk.

It's rather magical really, a moving display of where you are. My GPS is quite a basic unit (I don't want, or need, the full screen maps as I'm moving - it's a supplement, not a replacement - and besides, that would have made it much more expensive!). On the resulting tracklog there are a few places where the signal was lost and so when plotting the software made approximations, so there is the odd corner cut off and so forth (I was walking in London, remember - tall buildings everywhere, it's amazing, I think, that the log is so good!)

First GPS trial map

I walked up to the London Eye, and then to Trafalgar square, and on up Charing Cross Road to the British Museum.

I tend to go to the British Museum a few times each year, and so I decided today to become a friend of the museum, and I joined them.

I got a Michelangelo exhibition for just before 5pm.

During the day I went around the museum and did some sketching - some reasonable, some not - none what one might see as 'good' on an objective scale, but I enjoy it. I drew Parvati, the consort of Shiva, a drew one of the Parthenon sculptures, 'a blind contour' drawing of a Cypriot chappy, and a 'straight' drawing of him. These should appear on flickr when I get a round tuit. I also did a bit of peoplewatching - I'm not as happy with the sketches that resulted as I was last time I did this, everybody kept moving - it was a conspiracy!

The Michelangelo exhibition was pretty good - some of the drawings are incredible, they're so detailed and he makes them look so effortless. I found that even close up, when you can see the individual pencil marks, each one was just right. The place was absolutely packed though - the British museum do a timed entry system to minimise the crowding, but it's still quite busy. I'd guess a very early ticket would be best.

On the way back, I walked down Shaftesbury avenue, Haymarket and across Westminster Bridge.

This data was put onto a map using OziExplorer, which also outputs data in a Google Earth friendly manner.