[time-nuts] How can I measure GPS Antenna quality?
jimlux at earthlink.net
Tue Nov 22 20:55:22 EST 2016
On 11/22/16 10:13 AM, Mark Sims wrote:
> Attached is a screen shot from Lady Heather showing various antenna signal displays. The antenna was a cheap GPS/GLONASS patch antenna (mounted on a 3 foot ground level tripod ) connected to a rather nice NVS-08 receiver tracking GPS, SBAS, and GLONASS satellites (typically around 22 sats).
The usual "flat" plot for a 3 D pattern of a GPS antenna is to have the
radius = 90-elevation angle (so horizon is outer border), angle is
azimuth looking down on antenna, and color be power. Somewhere I saw
one that also integrated the multiple satellite tracks.
Another strategy is to plot it in u,v space. Color is power, but u =
cos(az)*cos(el) and v is sin(az)*cos(el) (or sin(theta) where theta is
the angle off boresight)
http://ww2.nearfield.com/amta/AMTA07-0092-GFM_SFG.pdf has a bewildering
variety to choose from
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