Saturday, July 23, 2011

Trusting Google blindfolded

Or maybe I should have picked a title like “do not trust Google Maps picking a route for you”. It was my first time using Google Maps when I was driving between different spots during the vacation. It was always OK to use it in the city or at the main roads interconnecting cities. With this experience I had a trust using Google Maps on the smartphone so that I did not even need to follow road signs.

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Ending up in the field with pomegranate trees  following this route for Dalyan to Sarıgerme made me notice that Google may have erroneous data too.

Things started to go wrong at step 3, seeing that the road is not as straight as Google thinks so; but it was heading where Google promised to. I kept following and ended in the field. Too bad I was not driving a 4WD to follow Google's route comfortably.


It was not Google's mistake actually as Google is working with local providers for maps, like this map was provided by BaşarSoft. Checking the web I noticed I am not the only one having this problem.

This little experience made me notice there is still a lot to depend on online maps blindfolded.

Friday, July 01, 2011

Touristy spots of Istanbul

Coming across the World touristiness map and The Geotaggers' World Atlas by Eric Fischer online, I wondered Istanbul’s popularity map. While Eric Fischer’s map for Istanbul could give an idea about the popular spots, what it really provides is the mobility map of the photographers.

The different colors represent different modes of transportation: Black is walking (less than 7mph), Red is bicycling or equivalent speed (less than 19mph), Blue is motor vehicles on normal roads (less than 43mph); Green is freeways or rapid transit.

While world touristiness map provides the popularity info, the resolution is too low to check the popularity at the city level.

Inspired with both ideas I downloaded the locations of all 100K+ geotagged pictures taken around Istanbul at Flickr. Below is the heatmap produced with pictures since the beginning of 2010. While it would be faster to create small grids of the city and download only the number of pictures for each grid (like what "world touristiness map" did possibly), this would not be able to create a high precision map. Because of this, I tried to download all the picture coordinates.


It is no surprise that the most hot area is the historical part of the city and by Bosphorus. The spots on the sea are mostly on the route of ferry lines.


Knowing the city a bit, you could expect this result before trying to plot the pictures. But still if you do not know the city very well, it can teach you new spots close to the city to see like those small red dots at northern part.