If you've ever lost a night's sleep because you couldn't wrap your head around how to build a Real Time Kinematic (RTK) GPS receiver without breaking the bank, then prepare to sleep like a baby. Why? Because researchers Tomoji Takasu and Akio Yasuda of Tokyo University have you covered.
The researchers developed an inexpensive, open source RTK GPS that runs on a beagle board, and better yet, they've posted instructions so you can do the same. And unlike traditional GPS, RTK units measures the shorter wavelengths in the satellite's carrier signal, which ultimately means greater accuracy.
Getting it work right, however, isn't an easy task. That's why Takasu and Yasuda deserve major kudos for printing the detailed instructions, which you can access here.