Peter wrote:
there is no (practical) way to baro-aid a tablet product
From here (again and again and again ):
“SkyEcho 2 includes an integrated baro altimeter. The altimeter correlates cabin pressure altitude to altitudes of nearby traffic to give you more accurate relative altitude alerts.”
Seriously, I’m not working for the marketing department of these guys. But reading the specs before commenting doesn’t hurt 
FWIW, in my TB20, an Ipad2 would lose GPS routinely
That is certainly a widespread experience (not just in TBs, but generally) but with a Garmin GLO on the coaming I would say that it never happens.
On the SBAS point (we really shouldn’t call it WAAS; WAAS does not exist in Europe, and this is a European forum), I would say that if your concerns are sufficiently great to worry about the advantages of SBAS enhancement for horizontal accuracy and integrity, then you should be biting the bullet and getting an approved SBAS receiver (GNSx30W, GTN or IFD).
Peter wrote:
It is standard in RAIM-capable IFR GPSs to have pressure altitude input.The GNS430 IM does say that pressure altitude input is required for RAIM, which I find surprising. Possibly it is using a RAIM algorithm that uses pressure altitude. AFAIK the use of pressure altitude can be used in lieu of an additional satellite for some calculations.
….
Whether this is the only way to achieve RAIM I don’t know.
Baro Aiding is not required for RAIM, but it does improve availability of calculating RAIM, particularly for approaches where the requirements are tighter.
Peter wrote:
A search on e.g.RAIM AND BARO*
digs up the answer
Good to know that I remembered correctly!
Bathman wrote:
I’ve never known my yoke mounted Nexus 7 ever to lose GPS signal.
It does not admit when it loose raw data/integrity but a good software will find the best guess where you should be 
In my opinion, that is better than you guessing using old fashion nav or using those fishy signal from low range NDBs
If you add this to it it works just fine but I am still waiting for a built-in solution
https://bad-elf.com/collections/plug-in-gps/products/be-gps-1008
Dimme wrote:
From here:
“Aviation Integrity SBAS and RAIM enabled TSO-C199 GPS provides position data for ADS-B Out transmissions.”
SkyEcho looks tip top, worth gold for “low & slow level GA with no transponders & mogas”
Flying VFR, relying on the moving map in Airspace Avoid on a Sony Experia, with a Nexus 7 as backup, I was looking for Beverly on my right, when I saw it directly ahead. I was about 1500’ due to cloud.
(Delivery trip with newly bought aircraft, and unfamiliar area.)
In the process of chasing my EASA IR renewal for which the flight test was done in Aug 2018, which the CAA “lost”, which their Chief Exec has written to me saying that due to what’s happened I will get a refund of the fee I have just been told that the examiner also needs to fill in SRG2199.
When I told them that I can’t see any reference to PBN on this form, they said it is OK to write PBN TESTED AND PASSED on the very bottom of SRG1157 (which was already sent in) and sign it. This is despite “PBN” this and that being written all over other forms in the application.
The story continues… thankfully this is required only once per life.
I wonder what procedure other CAAs around Europe are operating?
