Ublox Antaris 4
From Wildsong
I have Ublox AEK-4P and an AEK-4T development kits.
These consist of a GPS module (LEA-4P or LEA-4T respectively) in a small case with a USB interface, a serial port adapter and a patch antenna on a really long coax cable.
I will put more information here as I collect it...
Here is the serial port datasheet. File:Ublox serial port adapter.pdf
The AEK-4T is based on the LEA-4T module. The interesting thing about the 4T is that it can output raw data that can be processed to achieve centimeter level accuracy at low cost. See more at Low-cost RTK