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.:

Here are photos of the inside chamber of the DMCR antenna retrieved from the RTHS station.

Here are photos showing how the choke ring and antenna element become covered by water droplets as a result of both dew and rain.

We think 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.

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