Efficiency

[micha.d]

Thanks for the answers. I'll only respond to the things related to efficiency.

Interesting fresh observations.  The automatic feature of this TOA system has never, I don't think, been fully utilized.

. Well that's an argument for optimizing the auto as well, not only the efficiency display.
Isn't it possible to distinguish repeated and sporadic signals. All the repeated are noise. If really many station go for auto, then that might be a quick win.

It's certainly possible but you'd have to be really vicious with the filters. Due to a couple of VLF transmitters within 30 odd miles I have the lo-pass option fitted and set to 17 kHz. Still have plenty of signals used by the system.

That's a pretty good info. That gives me a good feeling that the noise can be managed. It's hard to find that out through the efficiency display. At least I did not make it so far.

If you are logged into LMO and viewing your station the Archives > List gives distance direction and number of participants. What I have not see it show is if a given signal was used. There is a "Participated" field but I've never seen it.

You could try downloading and using the MyBlitzortung.php script. I've hacked that on the Archives > Search result page to give me a count of how many of the displayed strikes my stations signal was used for.

Well, I don't see the mentioned data in one source, maybe I missed something. Either it's all stations (not just mine) or I don't get the "used" flag for my station.
I thought about writing a tool that downloads all the stats but all that requires effort and is only usable locally in the end. I would want to pimp the display for all members.

This is a good tool for helping to find a good balance, between signals sent and strokes recorded.

https://www.meteomelin.be/staticfiles/bl...egion=1&id=

I like this one, but it's also a "slow" efficiency marker like all the others. But again we could take some lessons learned out of it. Close to the diagonal is good, far away is bad. I think that is a part of the current calculation already.

I would like to change the measure for the efficiency of the stations. It may not be appropriate to calculate only one numerical value, but rather to introduce different possibly even competing measures for the efficiency of the systems.

The first value could indicate how many of the transmitted signals are involved in the calculated strikes. The second value would be distance dependent and indicates how many impacts with a certain distance to the own detector the station was involved.

The current combination of these values (thate what we are doing now) seems to be not usefull for adjusting a detektor.

Any ideas for further efficiency measures?

Ok, this is maybe only a starting point, but what would have helped me in the beginning is an advice what to change. Let's do some examples:

• The first point mentions to check for repeated signals. If they occur the advice could be to lower the gain or increase the threshold. I see this as a clear rule for manual or automated adjustments. It protects the server and is more relevant in regions with a lot of station. So the number of stations within 1000km could be taken into account. Detection of repeated signals can be done on server or client side to distribute the load. As soon as repeated signals are gone, this indicator is blind.
  
• After following the first advice I might have to look for the source of the noise to get better. I cannot imagine an auto for removal of the noise but maybe a noise comparison helps to understand why my station is not going to be on top of the list. The advice would be: reduce noise, increase distance to the noise etc.
  
• If the station has noise of a specific frequency, then the filters could be adjusted automatically. This might change over the day, so it's also a case for the automatic. All the frequency analysis graphs of the last n minutes could be accumulated to clearly see the noise frequency in the graph. That could show us if it's really a specific frequency that is there. Then the noise could be eliminated automatically by adjusting the frequency of the filters or asking the user to do it. We could even think about eliminating a specific frequency by notch filter calculations on the server. This is expensive because it must be done before using the signal.
  
• The second example above is the distance to the diagonal of the graph. There is no clear advice for me what to do. If I look at the graph, then several station are where they should be, the few others more down right should be having the noise problem above, right? They have a lot of signal without strikes. That is noise and noise is often repeated. So the indicator whould tell where you are and how important your noise problem is. This also works if you don't have much noise.
  
• The last question for the stations on the diagonal whould be: Should / Can they be more at the top right? You will only get to the top right with low noise. But you will also only get to the top right if there are strikes nearby. Did I get this right? If yes, I think a factor for each strike needs to be calculated. Nearby strikes count more, far away less. Don't forget the intensity is decresed with the square of the distance, right? I don't have a clear formula yet, but in principle, if strikes are nearby (value high), then it's easy and I should be top right. If strikes are faaaaar away (value low), then it's ok to be more left at the bottom. Calculating the ratio of the strikes value and the real detects should prevent that stations are going up and down all the time in the ranking. The limit is always the noise (again). To get a formula, we would have to keep some stations with stable settings and environment (including the noise) and play with parameters of our formula until they have a stable value over time I guess.
  

That was a lot of things circulating in my head. Let's see if you find something useful .