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I have just switched the markers on the map to use the new self-reported internal SNR scores. The logic is as follows: the HF-only self-reported score is used if available, if not the full-spectrum self-reported score is used instead, and if no self-reported score is available, the classic external score is used as fallback; this last case is mostly about receivers running an older version of the software.
Users choosing a receiver will benefit from up-to-date and instantly relevant scores, as by default self-reported scores are calculated every hour. As such you may notice how marker coloration now brightens up when nighttime comes and covers their area. HF-only scores are favored as it was pointed out that very strong MW bands tend to skew the scores. I don't especially like excluding signals below 1800 kHz, but a choice has to be made since it makes a significant difference in usefulness; and this is a shortwave receiver map, not just a map of remotes for commercial MW band broadcasts, so this is our editorial line.
Thanks to everyone involved for their contributions to the discussion, scoring code or monitoring framework. In the future I'm fine accepting as input whatever KiwiSDR receivers calculate and report as SNR score, so don't let the fact that the map uses those scores hinder further change or refinement about them :)
There are two fully adjustable noise blanker algorithms. And they both have an associated test mode, also fully adjustable. So you should be able to practice using them.
Unless your fence noise is weak or the pulses are not well-defined there shouldn't be a problem. I just tried it again (test mode) and it works great!
Okay, all should be good now (except for my splitting headache). I'm not 100% sure because it won't let me stay logged in for more than a few seconds (BT bastards). And your router isn't forwarding port 8073 connections to the new local ip address of course.
Sure enough, the Beagle guys made an incompatible change in how the .dtb file is loaded by Uboot. I'll have to figure out a change to support it.
About the purpose of the scores, and what score to use, I think there are several use cases, or maybe several schools of thought.
- Some people want a measure of performance of the receiver right now, because they want to choose one to listen to a signal right now, so that's what matters: for this, the best would be the most recent instant measure possible.
- Some people want a more general or abstract measure of performance, perhaps for self-improvement, perhaps to find a generally good receiver without a specific time or signal in mind - so a measure that doesn't depend on the time of the day: this would need for example a straight average of measures over at least a day/night cycle; Mark also suggested, instead of the average, taking the maximum SNR value over that cycle.
- Some people look at this with an even broader scope, and see this as a performance indicator that goes beyond external disturbances such as daily propagation conditions, space weather, temporary QRM, maybe even seasons: a simple solution for this would be a classic stateful metric, where each new measure updates the metric with only a partial weight - for example, the new updated score would be 90% current cumulative score, 10% new measure.
Of course, the SNR listing, the map markers and so on are different tools with different purposes, they don't have to use the same approach if several scores are available; this isn't one size fits all. I guess there's no problem displaying all available score options in the listing; they just have to be available. For the map, I think I have to choose what I do, but I'm listening.
The immediate value would be the most useful in selecting what to listen to at that hourly moment in time. Of course updating the map for all KiwiSDR receivers on an hourly basis might be a bit much for the site manager to take on.
That's no technical issue for me, it really makes no difference with the current state in that regard.
Just as a bit more information on this one, here's a spectrogram plot from one of the KiwiSDRs over a few days, and also the estimated total RX power (just from summing all the bins). The scales are not quite matching, still some work to do there.
I'm not sure what the clipping point of the KiwiSDR is, or how accurate the RX Power estimate I'm doing is.
Anyway, the day/night cycles are clearly visible, and you can see those large red bands of shortwave stations that are causing me problems at some times!
EDIT: The code to capture the required data and generate the above plots is now on github here: https://github.com/darksidelemm/kiwisnr-rrd
73 Mark VK5QI