What's outside the attic window?

Why .. it's the Mag-Net GPS datalogger!

the GPS decoder is tiny .. the receiver is hanging on the left of the yoghurt bucket
The Arduino code is simple How to use the incoming data? .. well there are heaps of fantastic websites that explain how to do it! For example .. https://learn.sparkfun.com/tutorials/gps-basics/reading-gps-data .. Oh .. is my roof only 18 metres above sea level?