[Colin] and [Fergus] have been working with GPS for years now, and like many contractors of really cool things, they’re often limited by the precision of off-the-shelf GPS units. While a GPS receiver is typically good for meters of accuracy, this just isn’t good enough for a lot of projects. What you need is centimeter-level accuracy, something the men have managed to finish with their Piksi GPS receiver.
Where many GPS receivers only look at the data coming from the GPS satellites orbiting overhead, the Piksi uses another technique, real-time kinematics (RTK), to identify the receiver’s location with exacting precision. The basic idea behind RTK is to look at the carrier frequency of the GPS signals at 1575.42 MHz. This frequency has a wavelength of 19 cm, compared to the alternating 1s and 0s of the that are transmitted at around 1 MHz, or about 300 meters between each bit. While centimeter-level precision isn’t possible with only one receiver, two of these Piksi boards – one base station and one on a vehicle, connected through radio link – can make for a very exacting high-accuracy GPS receiver.
Previously, commercial RTK GPS systems have cost thousands of dollars – making a quadcopter or other homebrew project that depends on this level of precision nonsensical. [Colin] and [Fergus] have built hardware that can bring the price of this setup to under $1000. As a bonus, the Piksi board can also receive from other constellations such as Galileo and GLONASS. A very outstanding piece of hardware, and we can’t wait to see the applications.