[time-nuts] Difference in GPS antennas

[Mark Sims]

I think that the patch antenna in the (Symmetricom) conical antennas is probably a higher quality patch than the ones in those $5 hockey pucks.  I get around 8 inch errors with the Symmetricom unit and 1 foot errors with a cheap patch antenna (ok,  it was the TAPR Motorola patch)  It seems to be a definite and repeatable difference... but we are dealing with black magic and statistics here.

Geodetic and survey grade antennas are usually some kind of patch mounted on a ground plane disk or choke ring structure.   These antennas are carefully designed,  tested,  and built to very high tolerances.  Also most of them support  the L1 and L2 GPS frequencies,  although L1 only survey antennas are available.  L1 only surveys depend upon having a reference receiver mounted over a precisely known point.

Some of the data collection runs that I want to do is with the patch mounted on a pizza pan and in a cake pan and see if that helps the performance by faking what a survey antenna does.

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