A GPS-at-GEO system is provided that includes a receive antenna design
that enables improved tracking of GPS space vehicle side-lobe signals.
The receive antenna design is a conical mode helix antenna configured to
produce a conical mode radiation pattern, which has zero gain at Nadir
and higher gain in the side-lobe signal regions. The conical mode
radiation pattern provides several advantages for GPS-at-GEO navigation
applications. For example, this mode provides higher gain in the GPS
space vehicle side-lobe signal regions for improved acquisition and
tracking performance and lower gain at Nadir, providing reduced noise
temperature and higher signal to noise ratio.