Garmin GSR56 (merged)

I’m not sure there is a “refresh” rate as such. Effectively you make a download and get whatever the latest weather is. Then at some later point you can make another download and get another lot of latest weather. How frequently the point from which you download is updated I’m not sure.

You can have it set up as auto download, in which case I’m guessing it might do a download each time something changes.

Not sure if I’ve really answered your question!

Well, I’m not sure either about this refresh rate, but Garmin is really evasive concerning that kind of information.
As a matter of fact, they just said that I could indeed (like you said) set an auto-update to have the latest weather datas downloaded, but I’d like to know how many times in a given lapse time.

The refresh rate in Europe for precipation is 15 minutes. See table 6-5 GFDS Weather Product Symbols and Data Timing, page 316 of the Cessna G1000 Pilots guide

I think asking for the refresh rate is in fact not the best questions. What you mostly care about with with data link weather is your average delay. There is 5min data available for parts of Europe but this system has too much delay:

5 minute radar data has a delay between 12 and 17 minutes
15 minute radar data has a delay between 3 and 18 minutes
(The range depends on where you are in the processing cycle)

As a bottom line for data link weather using the 5min radar data is not worth the additional transmission costs.

This is also the reason why our ADL110, ADL120 and ADL130 devices only update every 15 minutes like the Garmin GSR56.

Thanks Sebastian for that clarification. But just to be sure, if the GSR56 has a 15mn radar, it’s worthless sending an update every 5mn to have a new wx picture if that delay is higher then the radar ‘refresh delay (5-15mn), right
I use the GSR as a ’long term’ decision tool: I’d rather have a whole weather picture along my route (and then be able to plan a diversion) way before my weather radar sees the precip or convective wx, and then use the latter to avoid, but I need to know when the wx picture will be updated, because it costs as you said!

I’m not an expert for the GSR56 server infrastructure but I would suggest trying updates at 04, 19, 34 and 49 each hour. If that does not work out try one minute later. You can also turn on the automatic downloads and monitor when it will download.

Sunnday I had the occasion to compare the data link image of a cell to the on bord radar return and both did match quite well. On a side note no strikes detected in there.

You can also turn on the automatic downloads and monitor when it will download

I’ll try to get updates every 15mn for my next (long) flight and I’ll keep you posted for what I got.

@Jesse: Thx too, I have a G500 and this refresh rate for Europe is not specified in the G500 Pilot’s Guide.

Is ground WX radar info with 15-minute updates good enough to replace on-board radar for avoiding embedded thunderstorms? (Not penetrating, obviously.)

It is good enough if the development is slow and if you take a generous detour, also stay out of what is not yet a thunderstorm (i.e. yellow). If you want to navigate between cells, then it is not good enough.