Best inflight wx radar?

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Johnbo

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Johnbo
i use FlyQ with a Strux for the adsb-in weather and I have noticed that the radar layer data isn’t update as often as I would like and it seems to be inaccurate or scaled wrong. On the ground I use RadarScope which is a fantastic product that my meteorologist buddies recommend so that is what I am comparing to.

Are the issues I’m having with the adsb-in radar an issue with the source data or an issue with FlyQ?

Thx
 
ADSB-B Radar data is often very delayed.
(The actual term for it is FIS-B and you can google all the specs for it.)

All of the below are “best effort”. In high traffic areas these transmissions can occasionally be skipped for higher priority data.

NEXRAD data is transmitted every 2.5 minutes and the picture updated every 5. NEXRAD is available within 250 nautical miles of the station. Finding where stations are is possible in some ADS-B products, but generally... good luck. With those refresh rates, the worst case runs about 7.5 minutes delayed just by ADS-B itself and the data can also be slightly delayed getting to FAA. Roughly think “this could be ten minutes old” when using it for a weather picture.

If not within 250 nm of a station, the US Composite Radar is available. Lower resolution and much slower to update. Worst case is somewhere around 15-20 minutes.

ADS-B Radar products are advisory only and are not a suitable substitute for actual in-flight Radar. (Or your eyeballs.)

It’s free. You get what you pay for. Don’t be shooting embedded thunderstorm gaps with ADS-B Radar.

Which product is displayed is up to your vendor’s device. Also how they display the time stamp of the radar picture is also up to them. Know your gear and how to find out both pieces of information.
 
Out here in the southwest I find the old Bendix radar to work good. The weather display is current, not delayed and it is usually only good for 30-40 miles. I have used it to thread my way between thunderstorms.


Just remember to turn it off if being marshaled into parking or the lineman may not be able to have children....
 
Agree with Nate. My ADS-B WX doesn’t have the refresh of the XM NEXRAD we’ve got at work. Don’t really care for the quality of the returns on FF vs G530 or 500 with XM. ADS-B WX is definitely a important tool for SA though and it was invaluable for a XC I did a few months back. Without actual aircraft WX radar, it works well.
 
Velocity173 said:
Agree with Nate. My ADS-B WX doesn’t have the refresh of the XM NEXRAD we’ve got at work. Don’t really care for the quality of the returns on FF vs G530 or 500 with XM. ADS-B WX is definitely a important tool for SA though and it was invaluable for a XC I did a few months back. Without actual aircraft WX radar, it works well.
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Yeah I don’t have the specs for XM’s refresh rate here in front of me, but the Googles probably work where the OP lives. I believe it is faster to transmit but has the same upstream refresh rate from NOAA.
 
denverpilot said:
Yeah I don’t have the specs for XM’s refresh rate here in front of me, but the Googles probably work where the OP lives. I believe it is faster to transmit but has the same upstream refresh rate from NOAA.
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Not sure how much faster XM is but they keep advertising in Flying Mag their service over ADS-B. Personally I don’t think the difference between the two really matters. I’ve rarely seen ATC call outs or what I see outside much different from XM or ADS-B WX. We talk about game changers and for me, flying over 800 miles non stop VFR, cockpit wx is a game changer.
 
NextRad / ADS-B weather can be sufficient assuming you steer clear of serious weather. A few minutes' delay isn't likely to make a huge difference and ATC will call out the nasty stuff if your display misses it, which in my case hasn't happened yet. If you cut it real close, that might be a different story.
ADS-B.jpg
 
Cogito said:
NextRad / ADS-B weather can be sufficient assuming you steer clear of serious weather. A few minutes' delay isn't likely to make a huge difference and ATC will call out the nasty stuff if your display misses it, which in my case hasn't happened yet. If you cut it real close, that might be a different story.
View attachment 77808
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If you’re talking convective a few minutes is a life time.

ADSB/nexrad for big picture trending and planning, onboard radar pod for flying through the weather. I’ve had ATC advisories tell me something my onboard wasnt showing, both in needing to avoid something that wasnt there, as well as not seeing something that was. There is a reason lots of operators require real onboard radar to go IMC or night around convective.

I bring this over to my own flying too, if it’s convective I stay VMC and navigate via the windshield.
 
Johnbo said:
i use FlyQ with a Strux for the adsb-in weather and I have noticed that the radar layer data isn’t update as often as I would like and it seems to be inaccurate or scaled wrong. On the ground I use RadarScope which is a fantastic product that my meteorologist buddies recommend so that is what I am comparing to.

Are the issues I’m having with the adsb-in radar an issue with the source data or an issue with FlyQ?
Click to expand...

Nothing you get in the air will be as fast as you get on the ground.

Nothing you get on the ground is real time, and in the air you're delayed even further.

NEXRAD is a composite picture that is assembled from all the radar sites. The following is my understanding, and may not be 100% correct, but gives you an idea of why there's a delay and why you need to accept that and work with it:

First, the radars are making multiple sweeps at different angles to get different altitudes. (They even shoot straight up, which is the source of the data for the VAD Wind Profiler.) You can see one example in ForeFlight, where you can choose Radar (Composite) or Radar (Lowest Tilt). The Lowest Tilt is the lowest-altitude sweep only, representing precip that's probably reaching the ground or getting very close. Composite is all the altitudes put together.

Then, computers have to do a bunch of work to merge the data from multiple radar sites and sweeps, clean up ground clutter, etc. As I understand it, by the time a NEXRAD image is generated, at least part of the data is already several minutes old.

Then, it'd made available to the various providers, and if you're getting it over the Internet, you can see it now. But, if you're getting it over ADS-B, like @denverpilot said, it can be up to an additional 7.5 minutes old. So, figure that what you have on board in your plane is around 15 minutes old, ±5 minutes. Both ADS-B and XM NEXRAD are strategic, not tactical.

One useful tool is to animate the radar in ForeFlight or whatever your EFB is, provided animation of ADS-B radar is supported. That gives you an idea of which direction things are trending. Don't get in front of it.

It's been interesting transitioning to an airplane with onboard radar. It's much more difficult to interpret than NEXRAD, because there's no computer pulling out ground clutter and such. I'm playing with it and learning how to interpret it... But one thing has been abundantly clear: It looks nothing at all like the NEXRAD picture, because things move a lot by the time you get the NEXRAD picture.
 
There is a accident case study about following nexrad by ASI. Unless you have onboard radar, don’t mess with that, even with onboard radar I know a guy who flies TBM doesn’t like to punch through convective holes
 
Doc Holliday said:
Myth.

The weather radar in GA airplanes don’t emit enough radiation.
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Maybe so... But our radar is about as small as they come, and weight on wheels turns it off. You can theoretically turn it on on the ground, but it'll throw a warning first.

WannFly said:
There is a accident case study about following nexrad by ASI. Unless you have onboard radar, don’t mess with that, even with onboard radar I know a guy who flies TBM doesn’t like to punch through convective holes
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I'd certainly much rather go where I can see the storms visually in the TBM. No possibility of misinterpretation there! And when you're going 300 knots, going around weather doesn't take long.
 
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