How many marriages have been saved by GPS?


Long list of GPS satellites.

I have a distinct and unpleasant memory of my parents not-arguing-in-front-of-the-children. It was the early 1990s and my parents had decided to take us on a road trip across America. My dad's experience of driving the sleepy high-streets of the UK suburbs had not prepared him for the terror of the Los Angeles freeway at night. He was jetlagged and my mum, bless her, can't read maps. On the hard shoulder, of the wrong side of the road, they argued about whether the map really said that you…

Continue reading →

Reducing GPS accuracy in photos


Unix is user-friendly — it's just choosy about who its friends are.

Here's a quick one-liner to reduce the precision of location stored in a photo's EXIF metadata: exiftool -c "%.2f" -TagsFromFile @ -GPSLatitude -GPSLongitude photo.jpg (Thanks to the EXIFtool Forum for their help.) Why is this useful? Modern phones automatically attach a GPS location to every photo you take. GPS resolution is around 10 metres. When you share your photos, you're often sharing your precise location. I wanted to upload some photos to the Wikimedia Commons of an interesting…

Continue reading →

GPS at 30,000 feet


Undulating waves of sand.

GPS is a modern miracle. Using SPACESHIPS and RELATIVITY you can locate yourself anywhere on the planet. Fun fact! Your GPS won't work if you're above 18Km or going faster than 500 metres per second. Just in case you're a Soviet Guided Missile. But if you're on a regular international flight, you should be just fine! Here are some screenshots I took using the open source GPS Test for Android. Top tips: make sure you get a GPS lock and update your A-GPS data. It's also worth getting as close …

Continue reading →

Car Hacking - With Bluetooth OBD


Friend, colleague, and fellow geek, Sam Machin has introduced me to the wonders of the OBDII port! Essentially, OBD (On Board Diagnostics) is a port which is found on every car produced since the late 1990s. It allows garages to see all sorts of diagnostic information about your car, its engine, and all other manner of petrol-headed goodness. It's designed to be easily accessible and conform to a common standard. So, it's no surprise that a whole cottage-industry has developed around this…

Continue reading →