XM versus ADS-B Weather

[Top Heavy]

I currently have an Aera 796 and am paying circa $35/mo for the XM weather. Am considering buying a GDL-393D antenna to get the free weather and synthetic vision on the Aera 796.

Looking for input on the quality and presentation of "free weather" v. XM. Also how does the synthetic vision from the Garmin GDL-3D on the Aera 796 compare to the proprietary 3D view that comes with the Aera 796?

[Bob_Belville]

Can't comment on SV but I am happy with the free weather on GTN750 (via GDL 88). I had both for a short time with XM on a 696. But I trust the stormscope more than either when CBs are around. 

[Andy95W]

Most of this was discussed just a few weeks ago, to include ADS-B weather toward the end of the thread.

http://mooneyspace.com/topic/13206-gdl-39-3d-ahrs-performance/

[jkhirsch]

Edit: Yes that was dumb.

[mooniac15u]

If you are thinking about it from a cost savings standpoint I'm not sure it makes sense. The MSRP on the GDL is ~$900, 900/35 = ~25 years of XM service. (ceteris paribus)

(also ADS-b stuff should get cheaper the closer we get to 2020 as it seasons in the market)

If you are also getting the XM radio while flying it seems like you're better off with the XM.

I can't make a comment as to the advantage of the SV, or weather you are being forced to make ADS-b upgrades.

The XM weather is $35 per month not per year. The payback is 2 years.

[mooniac15u]

But I trust the stormscope more than either when CBs are around.

You must need that stormscope whenever you're on MooneySpace with all the "CBs" around.

[M016576]

Switched from XM to ADSB- very happy with the decision.

[Jeff_S]

I have both in the cockpit right now. If you're talking just NEXRAD, then they are similar, although it seems the XM product paints a fuller picture of all the precip, perhaps because it is showing more altitude layers all at the same time. I know that in general, the XM picture is somewhat more dire (read: shows more activity) than the ADS-B picture.  I do like the fact that with ADS-B on my iPad I can zoom in closer more quickly to check out the cells.

 

It also depends on where you fly somewhat. Even though the FAA claims there is universal coverage in the lower 48, there still seems to be an ADS-B black hole in the western Tennessee/Eastern Missouri area. I just did a flight from Atlanta to KC for Thanksgiving and there was a good 150 mile stretch in there where ADS-B coverage was absent.

[Piloto]

ADS-B coverage depends a lot of whether you are using a portable antenna or a belly mounted one. The coverage maps areas assume you are using a belly mounted antenna. Unlike XM coverage that is from the ground up for ADS-B you need to be at a minimum altitude to receive the signal.

José

[DonMuncy]

I like the XM weather better, but being a CB, I like not paying for it better yet.

[Top Heavy]

Talked me into it.

[cnoe]

After encountering a few holes in ADS-B coverage over the past 12 months (particularly at lower altitudes) I added the external antenna to my Stratus 2 last week (sticks inside the windshield with suction cups).

 

It enhanced my reception greatly as I routinely had 3-7 towers in range all the way across NM and TX over the weekend. On a previous trip across NM when I had to fly lower I had ZERO towers for a couple of hours.

 

XM is most certainly better for coverage down low, but the Stratus does pretty darned good, particularly with the external antenna.

 

Cnoe