[VHFcontesting] Favorite path analysis programs, and topo map question

[nosigma at aol.com]

Patrick,


Given your close proximity to Lakes Huron and Erie you might talk to some VHF/UHF folks in the area about propagation over water.  I had a nice informal chat with a VE station last winter about his portable escapades seeking out fall and winter time ducts over lake Erie for UHF and uW.  Much to my surprise they exist in winter and fall and he was able to use them quite effectively.  If I remember correctly he said that being up high (100 feet) over the lake was rarely the right spot.  He used isobar maps to locate good spots with grades and then a thermometer as he descended from above lake Erie on the North side (Canadian) down to the shore to find the ideal spot.  Sometimes it was 20 feet up, other times it was 50 or 70 feet up.  Small changes in altitude made big differences.  


I know this is not what you were looking for, but if its a predictable effect you may be able to use it to your advantage.  My only related experience in this is radar ducting in the Gulf of Mexico and off of the VaCapes, always hot humid summer days with classical temperature inversions.  


John



-----Original Message-----
From: Patrick Thomas <p-thomas at mindspring.com>
To: VHF Contesting <vhfcontesting at contesting.com>
Sent: Sat, Aug 4, 2018 10:45 pm
Subject: [VHFcontesting] Favorite path analysis programs, and topo map question

Hi all,

I'm trying to find good rove spots (not so much today but in general), and curious if anyone prefers splat, radiomobile, or something else, for doing topo mapping and path analysis.

Related to this, I've been trying to figure out a tool to provide a topo map with custom color gradients, rather than squinting at the topo lines in google or other terrain maps, or ballparking the greyscale one provided by splat.  For example, around here there are lots of rolling hills that are near 950-1000 feet, so unless you're above that height, you're likely not to be "in the clear."  A few places are in the 1000-1100ft range but it's really hard to pick them out visually.

It would be nice to have a greyscale gradient from say 500-1000ft, then a really abrupt gradient (like weather radar colors, etc.) every 25 feet tick above 1000.  But I can't find a tool to do this.  Anyone else have a solution?

Happy contesting to those participating in the distance contest!

Patrick
KB8DGC
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