Topic: VP2 lost signal from ISS to console during thunderstorm?

[evergreek]

Hello all,

I was wondering if any of y’all have experience iss to console communication failure during a heavy thunderstorm? It’s my first time watching the console during a storm and it seemed to have lost comms from the iss to the console during heavy rain and lightning  for around a minute or two .. I freaked out thinking that it was dead but I came back a few minutes later. Is this normal?

[Mattk]

Assume this is a wireless VP2? And yes for sure being spread spectrum RF then barriers (such as heavy rain) and Lightning will have an impact

[ocala]

Yes it's common during heavy rain. But you aren't losing any data it's just being temporarily blocked.

[evergreek]

Thanks for the info guys - glad to hear that it is normal - it is indeed a wireless VP2.

So -- when it loses signal - the ISS buffers the data until next successful transmit? (my cocorahs rain gauge and the davis matched exactly in total rain fall this morning - incredible).

[dalecoy]

So -- when it loses signal - the ISS buffers the data until next successful transmit?

As far as I know, the ISS does not buffer (or store) the data.  Missed transmissions are missed data.  The ISS does not know whether its transmissions are being received.

[johnd]

As far as I know, the ISS does not buffer (or store) the data. 

Only rainfall AFAIK. All other real-time readings will be missed.

And personally I wouldn't say it's common for heavy rain to cause signal dropout - that suggests to me that the signal strength (RSSI) is marginal. If you could increase it a bit (less distance, remove obstacles, align antennas better etc) then it probably wouldn't drop out.

[dalecoy]

As far as I know, the ISS does not buffer (or store) the data. 

Only rainfall AFAIK. All other real-time readings will be missed.

And personally I wouldn't say it's common for heavy rain to cause signal dropout - that suggests to me that the signal strength (RSSI) is marginal. If you could increase it a bit (less distance, remove obstacles, align antennas better etc) then it probably wouldn't drop out.

It would be useful to look at the Console Diagnostics, etc. 

And I also said "Missed transmissions are missed data".  As you know, the rainfall data isn't actually "stored", (in the sense of "when did this incremental amount of rain fall).  Total rain accumulates, and that figure will be received at the next good reception (unless, of course, the "counter" rolls over).  But the rain rate profile isn't available for the period of missing data.  That's probably "too much information". 

I should have said: TOTAL rainfall will (usually) be buffered.

[CW2274]

As far as I know, the ISS does not buffer (or store) the data. 

And personally I wouldn't say it's common for heavy rain to cause signal dropout

Concur. I don't recall ever seeing this. Can't say positively that it hasn't happened, but times like this when the weather is cooking is when I stare at my data the most intently, so it's not like I'm not paying attention.

[ocala]

As far as I know, the ISS does not buffer (or store) the data. 

Only rainfall AFAIK. All other real-time readings will be missed.

And personally I wouldn't say it's common for heavy rain to cause signal dropout - that suggests to me that the signal strength (RSSI) is marginal. If you could increase it a bit (less distance, remove obstacles, align antennas better etc) then it probably wouldn't drop out.

You are probably right John in regards to the rain data
I have watched the console during heavy rain and for example seen it not move from .20 for about 30 seconds then it shows .28. It will repeat this until the rain intensity drops.
As for signal strength, I do not believe that is an issue in my case. As you can see in the graph the signal strength is sufficient. Keep in mind I only lose the transmission during very heavy rain. [ You are not allowed to view attachments ]  

[johnd]

That's reception %. Signal strength (RSSI) is a different parameter that you can only see on the VP2 second wireless diagnostic screen. Personally I like to see it at 30 or above.

(Reception % is obviously related to RSSI in that if the RSSI drops too low then inevitably it will impact on reception %. But your % graph (as shown) doesn't necessarily rule out losing reception for eg 30 seconds at a time (I don't know what your archive intreval might be).

[ocala]

That's reception %. Signal strength (RSSI) is a different parameter that you can only see on the VP2 second wireless diagnostic screen. Personally I like to see it at 30 or above.

(Reception % is obviously related to RSSI in that if the RSSI drops too low then inevitably it will impact on reception %. But your % graph (as shown) doesn't necessarily rule out losing reception for eg 30 seconds at a time (I don't know what your archive intreval might be).

Count me as schooled. I didn't know there was another signal strength parameter.
I will have to check that one out.

[ocala]

After monitoring that screen for the past hour it generally stays between 39 and 43.
Interestingly, it sometimes drops to 32 and even dashes out completely for a second or two before going back to normal.
I will have to see the reception during the next heavy rain event to see if the two are related.
Thanks for bringing that to my attention John.
 

[johnd]

After monitoring that screen for the past hour it generally stays between 39 and 43.
Interestingly, it sometimes drops to 32 and even dashes out completely for a second or two before going back to normal.
I will have to see the reception during the next heavy rain event to see if the two are related.

Hmm, 40ish is usually pretty good and solid. The signal's not passing through a lot of foliage is it? I've noticed that wet leaves with potentially 1-2mm of water on seem to knock the signal back more than expected from the rain itself. (The actual thickness of liquid water in rain is not that great, except eg in monsoon conditions.)

[ocala]

Nope. No foliage at all.
But as I said before these were some real heavy rains.