[time-nuts] Distance between GPS Antennae

[Brent Gordon]

   The best answer is try it it and see what happens.  In my case two
   systems with patch antennas ten inches apart interfere significantly.
   Here are plots (using VisualGPS) of my position over a day or two.
   This is using a GPS from Sure Electronics.  Note that the standard
   deviation is 0 for over 100,000 samples.  As a side note, it must have
   some kind of heavy filtering going on to not show any position
   variation.  This kind of result is repeatable with this unit.
   This is the same GPS, same settings, same antenna, same antenna
   location.  The only difference is that I have a Trimble Copernicus GPS
   from SparkFun running at the same time.  The two antennas are about ten
   inches apart, attached to the same piece of metal.  Both are magnetic
   mount patch antennas.
   The green ellipse is the mean position and the black ellipse is the
   least-squares position.  Horizontal positions are included in the
   calculations if the HDOP is <=1.0.  Vertical positions are included if
   VDOP <=1.5.  The plot range is approximately 265 feet N-S and 160 feet
   E-W.  I think the blue lines are ones with HDOP<=1.0.
   The interference to the Copernicus by the Sure isn't as bad as the
   other way around, but it is present.  I have plots if anyone is
   interested.
   Brent
   On 12/18/2011 7:36 AM, Mark C. Stephens wrote:

Just curious, If I place  a pair of high gain active antenna next to each other,
 will they interfere with each other? If so what is the minimum distance apart?
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