Why is it only the front of the storm?
it is in the specs of the chip. probably because it is used to warn people that the storm is getting nearer https://cdn.sparkfun.com/assets/learn_tutorials/9/2/1/AS3935_Datasheet_EN_v2.pdf look at figure 17 on page 13
Peter, that is not accurate. Once the storm is overhead It will still detect strikes within a 40 km distance. It doesn’t matter which direction the storm is moving.
Well now I don’t know what to believe!
What does logic tell you. Read the information in the document. Then check your own station data from a storm. Then ask yourself, “Is that logical for a lightning detection device?” And does the document actually state it only detects the leading edge?
You can see what it detects, the strikes are a U shape as it approaches, passes over head, and moves away. At least thats what my Air’s show when it comes over head
From todays storm:
One thing I have noticed is my indoor air has lightning disabled, and it didn’t report strikes. But ever since the Tempest system came online, it also started reporting them. I assumed this was because they were in-fill from the 3rd Party sources used on the Tempest (I can not see any reason why the 3rd party data can not be reported for users with an Air, its not like the data has anything to do with the device at the users end, when its coming from the WF backend). But if that is not the case, then I seem to have found a bug?
I totally agree. It seems like tempest lightning detectors are on people’s roofs opposed to the air at 5 to 6 feet on the ground. Of course being at that height of 25 to 30ft u will detect lightning much farther. This data needs to be brought to original air units
Regardless of height the range is at 40 km.
You may be right Gary, but why the difference of the 2 graphs of lightning from 2 weather stations 5 blocks apart. 1 tempest and 1 air. Unless its a software difference. Just boggles my mind
I can’t answer to that. @WFstaff will have to explain the difference. I know there has been an issue with the firmware concerning the Tempest and lightning but I don’t have the details.
“The AS3935 can detect the presence of an approaching storm with lightning activities and provide an estimation of the distance to the leading edge of the storm…”
(this is from page 13 of the datasheet @sunny shared), and this description agrees with the graphical representation in Figure 17. Now the question is, is what is the “leading edge”? The datasheet goes onto to say:
“… where the leading edge of the storm is defined as the minimum distance from the sensor to the closest edge of the storm”.
So it is quite possible to interpret this as the trailing edge essentially becomes the “leading edge” when the storm has passed overhead. Unfortunately we don’t get enough lighting in the UK to really test this, hence my unfamiliarity.
indeed that’s the case. Here you can see a typical storm reported by Air and one by Tempest. (not the same storm)
the sensor doesn’t know the direction of the storm. It does what it does. And yes, we humans might call it the trailing edge, because we know the direction of the storm.
it IS a software difference.
Note that although the graph of tempest is impressive, it mostly shows data from other sources. I would like to see what is measured with MY system. As mentioned, I propose to show the third party data as dots and the station’s data as the familiar bars.
That is certainly how I interpreted it.
We are due storms for the next 2 days if the alerts are to believed (red alert for 2pm until 2am for me), so hopefully some more opportunity to view
Yes, this was my mistake. I interpreted “leading edge” too literally.
I must have angered some lightning god though, as no sooner did I say “we don’t get lightning in the UK” we got hit by a big storm!
Exactly. To say that
is not only misleading, it’s totally wrong. It will detect any strike within it’s distance parameter. When the center of the storm is overhead and a strike hits 100 yards from your Sensor array, do you really think it won’t be detected? Of course it will!
That table simple shows how the detector tracks the edge of a storm. In fact it might not be the leading edge. It’s the edge that passes closest to your site, which could actually the side of the storm.
What’s puzzling is why the datasheet refers to the leading edge at all then. It would clear up much confusion if they just referred to the “closest edge”. The use of leading edge implies some sort of directionality, which is just not the case.
I’ve made an agreement with myself not to go into Gary’s postings anymore. It would be better if he ignored mine as well.