home made ferrite antennas
#10
(2017-07-23, 15:32)pasense Wrote: Cutty,
you are right when the station is within a network of other stations which are reasonably close by and where the staion is filling a gap. But I am now testing a "lone" station - the first one on the Canary Islands - and there is simply no station closer than about 1000 km. In addition, the low signal attenuation over sea water gives a much better detection range than for stations on land. So for the stations which are looking out over the sea one should recommend to go for large detection range in order to cover the ocean areas, which are also interesting from lightning detection viewpoint. Over the sea location accuracy is not so important than over land, but detection efficiency is. What is your opinion on this?
My Opinion? Dodgy
I say go to all Manual Mode, stay there, Open 'er up with highest gains, lowest thresholds that keep you out of interference. then monitor it for a month or two, especially as we move into tropical weather season.
Gradually you'll determine your best operating parameters... but AUTO may drive your crazy during this process, since it keeps playing games with your gains and thresholds.  Have Fun, and learn about what's happening...

Now you can skip this ling-fingered 'thinking out loud' that follows:

As  I understand it, the 'ground wave' component of the 'groundwave' element does have a longer range, with the space wave still remaining 'line of sight'...because of the water,..,. the 'skywave' reflections still doing their bounce thing...  The higher frequencies have pretty much 'vanished' by this time, from the broad impulse energy.... and being able to detect at distance with quality is very important in those areas of low coverage.... True, the accuracy won't be perfect if everybody is at 4000 KM,  and the ability to detect a high percentage of the actual strikes will be degraded, simply because there aren't enough stations detecting them....
I've had experience (contintental) in both areas... When I got my first  RED there were a total of 22 stations in the Americas, and about 6 pr eight of them were pioneer Greens in the Caribbean Islands and South America! ... at the same time, My local EMI environment was lower than it is today, and I could copy many the same strokes.  I could pretty much run 'wide open' and consistently hit strokes over 4000 -5000 km.. Our 'deviation accuracy' got us all excited if we were within 8-10 km Circles... and the 'effectivity' of my RED would be in the 90% range as calculated then.
Today, with more stations, more network strokes detected, I consider myself lucky to show a 40% network effectivity, with today's calculation method,  since I now am forced to by local noise to run reduced gains., higher thresholds, on both my RED and BLUE.  However, with more stations, many of us running lower distances,, I've seen the deviations network-wide drop to consistently <2-3 KM and have personally located ground hits that the 'center' deviation point was within meters of the actual discharge area or object.
So the accuracy potential is there, but the qualifying factors are very variable.
One of the approaches that Blitzortung is using is 'multi-region'... for example, your station shares Americas and Europe, and would be supported by at least some 'determined' 'boundary' stations in both regions. (I'm not sure if or how specific stations are  determined  for that -- or if they're currently just using the 'whole' region... things change from time to time), . 
So, my "opinion" is generally 'run the best gains and lowest thresholds' you can and as broad a bandwidth as possible'..  in my case, the bandwidth is attainable, but I certainly cannot run "hot".... because of the environment'... my Best gains are about half what the used to be, and about 20 mv higher thresholds!  I also cannot use "Auto" mode...
So looking at "Effectivity" and so forth as 'arbitrary', many of us don't but a lot of weight behind those calculations in general, because they are 'guidelines' and very arbitrary calculations... they're NOT worthless, and attention should be paid to them, but they don't mean that my station isn't performing, or cannot perform, as well as any other given station....  Our network includes both North and South Americas, lots of ocean, etc.  and at any given time, I'll NOT detect a large percentage of the strikes within the network! 
When you look at the 'efficiency' and 'effectivity'.... which in many respects are somewhat arbitrary calculations, and relate to 'network' totals, at the moment this is typed my BLUE is hitting 44% effectivity up to 5000KM and 77% up to 500km ... which is outstanding for me.  My Red is at 40% and 78% ... not too shabby.
Now, the GOTCHAs Here, are
1.  Number of signals sent... too many 'noise' signals lowers effectivity... since total signals is a prime factor.
2. Where are the strikes located?  If too many are outsider my 'effective range', but still 'network' detected, I don't score as well.
Over on lightning maps, I've a Locating ration of 50% and a strioke ration of 48% in BLUE and is 45% and 43% ... both of which again relate to number of strikes, and number of detections, with slightly different computation paradigms, and another factor thrown in... number of stations participating as a detector, and number used as locators. ..again this is quite good for my situation.
For my own use, since I have zero control of where the strokes are occurring, how many stations are operating that detect them, which stations are used as 'locators', etc, I 'rule of thumb' my current operating 'efficiency'  beginning with 'signals sent'... If I'm sending a bunch of signals, but not detecting strokes, I'm sending noise.
In your case, I'd say go "wide open"... you'll learn when your gains are producing 'noise' signals... you'll be able to recognize the difference between those distant 'skywaves' and just noise... at first a lot of your signals may look like 'noise' and in fact may be discarded... but in reality, they ARE
distant strokes, but not enough other stations 'detected' them!
I'm not sure how Egon would classify you "signals' with a minimum number of detectors to be recognized,.,.. in Americas, last time I checked, a 'signal' required 8 total detectors to be classed as a stroke... I think the minimum for Europe is higher, but won't guess at it
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Messages In This Thread
home made ferrite antennas - by opadavis - 2017-07-22, 00:53
RE: home made ferrite antennas - by readbueno - 2017-07-22, 01:26
RE: home made ferrite antennas - by opadavis - 2017-07-22, 04:08
RE: home made ferrite antennas - by cutty - 2017-07-22, 10:58
RE: home made ferrite antennas - by Dale.Reid - 2017-07-22, 01:46
RE: home made ferrite antennas - by opadavis - 2017-07-22, 14:42
RE: home made ferrite antennas - by cutty - 2017-07-22, 15:23
RE: home made ferrite antennas - by opadavis - 2017-07-23, 14:42
RE: home made ferrite antennas - by pasense - 2017-07-23, 15:32
RE: home made ferrite antennas - by cutty - 2017-07-23, 18:36
RE: home made ferrite antennas - by pasense - 2017-07-23, 19:34

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