ADS-B vs. XM Weather

gdtrfb58
Posts: 58
Joined: Wed Mar 13, 2013 1:17 pm

ADS-B vs. XM Weather

Post by gdtrfb58 »

I know that XM weather has much more information available [/i, but I am wondering if that additional information is actually displayed on the HXr.
At the very least, XM has higher resolution NEXRAD as well as lightning strikes, TFR's, winds aloft and cloud tops.

Is this information displayed on the HXr?
Bobturner
Posts: 425
Joined: Mon Mar 11, 2013 6:34 pm

Re: ADS-B vs. XM Weather

Post by Bobturner »

I used to have XM lite (or whatever the $35/month subscription was called) but have now dropped it in favor of ADSB (free!).
1. The "higher resolution" of xm is an illusion. It does look prettier, but it suffers the same latency problem (time delay) as ADSB. Storms move, and you cannot count on the "higher resolution" for anything other than giving you false confidence if you cut it too close.
2. I display data on an HX and iPad (WIngX); get it from a Skyradar D2 (HX via USB; iPad via wifi).
3. I see radar, METAR, terminal forecasts. Also I do get TFR info. And of course traffic, which xm cannot give you.
4. On more than one occasion I found my xm would not work; I needed to call or contact XM to "re-authorize". This is a real pain if you're already airborne.

I have no plans to go back.
GRT_Jeff
Posts: 652
Joined: Tue Dec 11, 2012 12:11 am

Re: ADS-B vs. XM Weather

Post by GRT_Jeff »

The XM radar data is a little higher resolution and arrives all at once, every 5 minutes. We don't support many of the XM data sets. We don't display cloud tops. We don't show any of the separate data for Canada. We only support NEXRAD, lightning, METARs, TAFs, TFRs, winds aloft, and AIRMET IFR graphics for the US. We show loops for the XM radar, but that's still on our to-do list for ADS-B. We don't show the long-range (CONUS) low-resolution radar from ADS-B yet, so you only see the nearest couple hundred miles currently. Winds aloft should be available on ADS-B, but that's also still on our to-do list. We don't show the ADS-B AIRMET or SIGMET data.
gdtrfb58
Posts: 58
Joined: Wed Mar 13, 2013 1:17 pm

Re: ADS-B vs. XM Weather

Post by gdtrfb58 »

So it sounds like XM will give me the following additional:
  • higher resolution NEXRAD
    Winds Aloft
    Lightning
    Airmet/Sigmet Data
    Looping NEXRAD
Some of these will someday make it to ADS-B

I already have ADS-B (Skyradar DX). What happens if both are connected? Do you have to/can you choose which to display?

You may ask "If you already have the ADS-b, why bother?" I had the XM receiver laying around and it was easy enough to mount in the nose and connect the USB. I figured that I could activate it for the summer months and then cancel it. The lightning data is useful (Stormscope is obviously a much better resource, but somewhat challenging to get to work in a Fiberglass aircraft).
Bobturner
Posts: 425
Joined: Mon Mar 11, 2013 6:34 pm

Re: ADS-B vs. XM Weather

Post by Bobturner »

At the risk of repeating myself: the higher xm resolution is not real. The "age" number is the time since downlink, not the time since the data was first taken. Use with care.
If you have an iPad with WingX, your Skyradar can connect wirelessly to it and display a lot of the ADSB weather at the same time it's on the HXr. This includes distant nexrad data. I don't know if it shows lightning or not.
Last time I looked, xm charged an initialization fee, to discourage frequent activate/de-activate requests.
GRT_Jeff
Posts: 652
Joined: Tue Dec 11, 2012 12:11 am

Re: ADS-B vs. XM Weather

Post by GRT_Jeff »

You can use XM WX and ADS-B at the same time. The EFIS will try to display both, with ADS-B data on top of the XM data. For text data like METARs and TAFs, XM data will be preferred. You can't switch between them. I don't know the subscription suspend/restart details, but other satellite services have fees for that, so check on that. Lightning is not available over ADS-B, although I've read they're considering it.
gdtrfb58
Posts: 58
Joined: Wed Mar 13, 2013 1:17 pm

Re: ADS-B vs. XM Weather

Post by gdtrfb58 »

Well, I got it working today. I called XM (15 min on hold) and they activated without an "initialization fee". I will use it (at least to and from OSH) and see if it is worth it. I already like the "Loop" feature.

Jeff-
-I have to select something to display lightning, or does it appear anytime I turn on "Radar"?
-Is there a way to view the radar overlaid on a sectional?
GRT_Jeff
Posts: 652
Joined: Tue Dec 11, 2012 12:11 am

Re: ADS-B vs. XM Weather

Post by GRT_Jeff »

By default, an HX, HXr, and SX will show lightning on any map page that isn't showing a chart or HSI. There is a setting for what pages to show lightning on in SET MENU, Moving Map. The HX and SX also have an LTG button to toggle the lightning on and off. We don't have an option to overlay any weather data on top of the charts.
Bobturner
Posts: 425
Joined: Mon Mar 11, 2013 6:34 pm

Re: ADS-B vs. XM Weather

Post by Bobturner »

Your Skyradar will display ADSB wx radar on top of a WingX sectional on an iPad.
I suggest you program the specific address for re-activating xm wx into your iPad. Much quicker than the telephone.
gdtrfb58
Posts: 58
Joined: Wed Mar 13, 2013 1:17 pm

Re: ADS-B vs. XM Weather

Post by gdtrfb58 »

Bobturner wrote:Your Skyradar will display ADSB wx radar on top of a WingX sectional on an iPad.
I suggest you program the specific address for re-activating xm wx into your iPad. Much quicker than the telephone.
Yes- It will do the same on FltPlan Go, on either an iPad or an Android FOR FREE. You can also connect to the XMWeather and do the same. Just wanted to do it on the HXr.
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