Dependency on GPS signal

[jr970]

I see from the documentation that the GPS signal is used to check for drift in the gyro's and that pitch information becomes invalid without GPS.

Just wondered how long a GPS outage will the D1 tolerate - does it flag up invalid pitch immediately or are you OK for a short drop of GPS signal ?

 

[Dynon]

Short drops are no problem. In fact, it will work with no GPS for a minute before the attitude is removed. During that time, you won't have GPS speeds or ALT - elements that come directly from the GPS position/speed fix, but the attitude will keep giving you its best effort solution. It may be degraded though: from the manual:

"Lapses in GPS coverage may degrade attitude accuracy, depending on the length of the outage.
During short lapses, the message GPS LOST: CROSS-CHECK HORIZON will appear at the bottom of
the display to indicate that the D1’s attitude indication may be degraded and should be
interpreted cautiously. Additionally, the indications that rely solely on GPS will be replaced with
red Xs. If the GPS signal is lost for a more substantial amount of time, the D1’s attitude will also be
replaced by a red X to indicate the D1’s inability to determine attitude. "

In practice, once you have a lock, it's usually solid.