Blitzortung.org Forum

Hi,
I have been looking at the data on the lightning maps website, and I was just wondering if anyone knows what and how the efficiency of the station is calculated?
Thanks. Kerri

No answer ?

I'm also interested in how this value is calculated.

Thomas

Efficiency = sqrt( stroke_ratio * signal_ratio )

That's not correct

After some experience I found :

Efficiency[%] = sqrt( quota_strokes_per_h[%] * quota_signals_per_h[%] )

Efficiency[%] = sqrt( stroke_ratio[%] * locating_ratio[%] )

or better :

Efficiency[%] = sqrt( ( strokes_station / stokes_summary ) * ( strokes_station / signals_station ) ) * 100

Efficiency[%] = sqrt( strokes_station² / (strokes_summary * signals_station ) ) * 100

Is this correct ?

Thomas

i can say i'm happy with my efficiency.

(2015-06-05, 14:32)Knickohr Wrote: [ -> ]That's not correct

Oops, sorry.  You are right!

Hi Folks,

I have changed the computation of the effectivity shown in the station list at blitzortung.org (this is not the efficiency of lightningmaps.org you have discussed above). The time period is 1 hour. I need the following notations to explain the computation.

Strikes (x,s) = number of strikes in a rage of x km to station s

Hits (x,s) =  number of strikes in a range of x km to station s at that station s was involved

Signals (s) = number of signals of station s

Strikes = total number of computed strikes of the region to that the station sends data

min (x,y) = minimum of x and y


Then we have:

Effectivity_50 = Hits (s,50) / Strikes (s,50) * min (Strikes / Signals (s), Signals (s) / Strikes)

Effectivity_500 = Hits (s,500) / Strikes (s,500) * min (Strikes / Signals (s) /, Signals (s) / Strikes)

Effectivity_5000 = Hits  (s,5000) / Strikes(s,5000) * min (Strikes / Signals (s), Signals (s) / Strikes)

If a denominator is zero, the effectivity is zero.


This is the old effectivity value multiplied by the factor min (Strikes / Signals(s), Signals(s) / Strikes) to consider also the strikes/signals relation (and to punish the stations that send a lot of trash  ).

The effectivity should only be considered as a relative measure of the performance, although a value of 1 can be obtained.

Much fun,
Egon

Thats very interesting Egon !

Some days ago, I do some experience with this :

http://forum.blitzortung.org/showthread....28#pid9628

Thats not exactly the same, but the result is nearly identical. Good performing stations are "playing" in the middle of the x-axis with high efficiency on lightningmaps.org (on the top of the "mountain"). But now, if you calculate the efficiency in another way, I have to look, if my graph is already up to date.

Thomas

(2015-06-14, 21:35)Egon Wrote: [ -> ]Hi Folks,

I have changed the computation of the effectivity shown in the station list at blitzortung.org (this is not the efficiency of lightningmaps.org you have discussed above). The time period is 1 hour. I need the following notations to explain the computation.

Strikes (x,s) = number of strikes in a rage of x km to station s

Hits (x,s) =  number of strikes in a range of x km to station s at that station s was involved

Signals (s) = number of signals of station s

Strikes = total number of computed strikes of the region to that the station sends data

min (x,y) = minimum of x and y


Then we have:

Effectivity_50 = Hits (s,50) / Strikes (s,50) * min (Strikes / Signals (s), Signals (s) / Strikes)

Effectivity_500 = Hits (s,500) / Strikes (s,500) * min (Strikes / Signals (s) /, Signals (s) / Strikes)

Effectivity_5000 = Hits  (s,5000) / Strikes(s,5000) * min (Strikes / Signals (s), Signals (s) / Strikes)

If a denominator is zero, the effectivity is zero.


This is the old effectivity value multiplied by the factor min (Strikes / Signals(s), Signals(s) / Strikes) to consider also the strikes/signals relation (and to punish the stations that send a lot of trash  ).

The effectivity should only be considered as a relative measure of the performance, although a value of 1 can be obtained.

Much fun,
Egon

Hi Egon,

I get the general idea of the new computation (quite hard for someone one who sucs at maths...)  But i am trying to figure out what the Y in "min (x,y) = minimum of x and y" stands for. I thought i'd just ask .

Gerhard

(2015-06-14, 21:35)Egon Wrote: [ -> ]This is the old effectivity value multiplied by the factor min (Strikes / Signals(s), Signals(s) / Strikes) to consider also the strikes/signals relation (and to punish the stations that send a lot of trash  ).

Hi Egon.

I think it´s a good idea to punish station with bad effiency, but i do not understand, what this factor is. If i look in the stations list i see my station has sometimes not so good efficiency, although there are some signals and many lightning strikes. 
I have (mostly around the weekend) short periods with a lot of noise, often only once a day. Is that the reason for worse efficiency? Is the time period of your factor 1 day or longer?

Cheers

Knolau

The calculation of the performance should not be taken so seriously. The additional factor

min (Strikes / signal (s), signal (s) / Strikes)

does not always make sense. The main problem is the lack of information.

When a strong storm is far away, which is possible if the region is very large, then the factor signal(s)/Strikes is very small, although the station is very well adjusted. It is just a compromise.

Much fun,
Egon

I played a little bit with the "new" efficiency :



Creating a small script which shows it in a 3D-diagramm. It's updating every Minute. Good performing stations are in the middle.

Thomas

(2015-06-25, 14:57)Knickohr Wrote: [ -> ]I played a little bit with the "new" efficiency

So did I:

Example:
http://crna.zapto.org/plotblitz/efficiency.php?id=233
(Database is still building)

Usage:

Optional Parameters:
xsize = diagram width (default 1440) [x - 3000]
ysize = diagram height (default 400) [y - 3000]
line = line width (default 2) [1 - 20]
noslope = disable line smoothing (default 0) [0 or 1]

Today, some small storms are coming in. It's nice to watch the 3 different efficiencies (S,M,L) for my stations :





Efficiency for station 1006 over the last 24 hours (database ist still building up) :



(red = efficiency L, green = efficiency M, yellow = efficiency S, blue = efficiency from lightningmaps.org)

Thomas

Quote:EgonThe calculation of the performance should not be taken so seriously. The additional factor

min (Strikes / signal (s), signal (s) / Strikes)

does not always make sense. The main problem is the lack of information.

When a strong storm is far away, which is possible if the region is very large, then the factor signal(s)/Strikes is very small, although the station is very well adjusted. It is just a compromise.

Much fun,
Egon

I am puzzled  I'm trying to get optimal results, and I use the participants page for checking the results. For what I understand the signals-rate is used in the calculation. So how can it be that one station has about double the signals, and less strikes be higher in the ranking? This would mean that sending more signals, and record less strikes is better... [attachment=2137]
But I could be missing something...

Gerhard

I'm interpreting it this way: if there are only few strikes in your range (50, 500, 5000), it isn't affecting the efficiency much, when you have a lot of signals.
There is no optimal setting for all eventualities. I think if you're in the two-figure-number efficiency, it's all good

(2015-07-19, 14:37)Gerhard.Wittevee Wrote: [ -> ]

Quote:So how can it be that one station has about double the signals, and less strikes be higher in the ranking? 

 Good question  I regularly take a look at this tables to control the work of my station and to compare it with the stations in my neighborhood. BO Neighbors
But very often i don´t understand  what I see. There shouldn´t be so big differences.
[attachment=2138]
The explanation of Egon does not convince me. I think there is something wrong with the new calculation.  I know, that I should not take it seriously, but I am always surprised about the results.

Cheers

Knolau

Quote:I know, that I should not take it seriously

I agree that we should not have a competition. That does not help the network as a whole. But these values are the only way to compare, and to improve our stations. Those improvements are in the interest of the network as a whole. That is why, as Egon wrote (with a  ) "To punish stations who send a lot of trash",  a calculation taking the number of signals into account is a good idea. But comparing just got harder. With the old calculation I could change gain- or threshold and see the station creeping up the list, or going down the list. The new values change constantly, so comparing even your own settings is virtually impossible. 
I'd like to see a sort of "quality"-value that is comparable. Not for competition, but comparison.
Gerhard

The best way to tune a station is to optimize it in this way that every detected signal is a stroke !

But not every stroke is registered by a single station. Try to optimize "quotas" Locating ratio and Stroke ratio at lightningmaps.org. A good starting is, if both values has nearly the same value, whether they are low or high.

Your station doesn't have the claim receiving all strokes (in your area) !

Thomas

(2015-07-20, 09:21)Knickohr Wrote: [ -> ]The best way to tune a station is to optimize it in this way that every detected signal is a stroke !

But not every stroke is registered by a single station. Try to optimize "quotas" Locating ratio and Stroke ratio at lightningmaps.org. A good starting is, if both values has nearly the same value, whether they are low or high.

Your station doesn't have the claim receiving all strokes (in your area) !

Thomas

Thanks Thomas,

I am aware of the fact that there are more ways of optimizing my stations. But this does not answer the questions that I posted here. 

Gerhard