[time-nuts] GPS message jitter (preliminary results)
holrum at hotmail.com
Tue Jul 19 13:20:28 EDT 2016
I ran some tests on the message timing of some V.KEL gps receivers in both NMEA and binary mode. These receivers are the cheapest ones I have (3 for $15 - $20, shipped). They use a SIRF III chip and have an on-board ceramic patch antenna. They performed amazingly well. No problems tracking sats indoors in a very poor location. Message jitter was less than 20 msecs peak-peak, standard deviation less than 2 milliseconds. ADEVs at tau 10000 after an overnight run in NMEA mode (hardware serial port) were in the 1E-7 range! They also have a 1PPS signal on the connector so no need to go digging for a place to bodge on a wire like with some of the other cheap GPS modules out there.
V.KEL also makes a Ublox based version of the module (around $22 for one)... mine reports that it has a Ublox 7 chip, though V.KEL's part number implies that it a Ublox 6.
More information about the time-nuts