This is an index to photographs related to
the SCIGN radome project.
Photos are by John Galetzka and Ken Hudnut. The material
reported here results from an ongoing SCIGN collaborative effort by John Galetzka,
Frank Wyatt, Stephen Dockter, and Ken Hudnut.
(last update Oct. 5, 1998 at 4:00 p.m.)
Here is what motivated us to build a stronger dome - if we can break them,
so can vandals:
Here are some relevant items from earlier in the prototyping stages -
prototype tall and short domes, how they mount onto a monument, etc.:
- This is what can happen if a station's antenna is not covered by any radome
(quite possibly a worst-case scenario?).
Here are photos showing how the choke ring and antenna element become
covered by water droplets as a result of both dew and rain.
this likely causes GPS signal propagation to change. We'll be adding
some more photos showing how the antenna progressively dries off after
both rain and dew (it takes a long while, and can be quite asymmetric
when the sun is shining). We are concerned about this, and how dew and
rain will behave on the new SCIGN radome (and how that may effect the
propagation of GPS signal). But we are also concerned about
how water droplets behave on the choke ring and Dorne-Margolin element
when a radome is not present at all. It appears that the surface of
the Dorne-Margolin element is able to absorb water - probably the paint
coating itself is absorptive. That seems likely to be a problem for
high precision GPS applications, and argues in favor of placing a radome
over the antenna to greatly reduce wetting and drying of the antenna element.
These reports are preliminary and have not been reviewed for
conformity with U. S. Geological Survey editorial standards.
Any use of trade, product, or firm names is for descriptive
use only and does not imply endorsement by the U. S. Government.
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