RAGA - Redundant Array of Gps Antennae

Poul-Henning Kamp
Revision 2003-12-06


I'm building a small series of GPS+OCXO based NTP servers, and as part of that project, I currently have 10 identical Motorola M12+Timing GPS receivers available.

The receivers are the "remote" version where the receiver is colocated with the antenna. The advantage to this arrangement is mainly one of cabeling: Normal GPS antenna coax is expensive and lossy, making long cable-runs a major problem. The remote version instead has only approx. .5" coax cable to the antenna and up to 1km of cable with a robust RS-422 serial signalling between the computer and the GPS receiver.

I have mounted them on a piece of 2 by 4 with a spacing of 20cm, and put them the op the top of my shed which is the best reception I will get with the cable-length I have.

In addition to the necessary quality-tests on the NTP servers, I plan to run a number of experiments on them while I have this rather unique opportunity.

Ideas for interesting measurements are most welcome, and the results will be posted here as I have them.

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