What does the "GPIRS integrity" mean here?

[oakhg]

If the GPIRS data does not comply with an integrity criteria, the GPS mode is rejected and radio position updating is used, as described in earlier posts.
Could anybody tell me how to understand the "integrity criteria" mentioned above

[Carnage Matey!]

I would guess that it's some sort of reasonableness test to ensure that a duff GPS signal doesn't skew your IRS position. If the GPS position differs from the current IRS position by more than a certain amount then the GPS is ignored and the IRS update from radio nav aids.

[oakhg]

Well, thanks for the reply. Actually, I am having a A320 transition training, and everytime I turn the ADIRS off on the simulated device, then "GPS PRIMARY LOST" will appear in the bottom of the ND , which give me the impression that GPS could not be used when the ADIRS are off.

Does this phenomenon comply with the real flight?

One thing else is that if all IRS go off during flight, can GPS still be serviceable for locating position?

[mutley320]

Adirs/gps

My understanding would be that the system was designed prior to GPS becoming available and accepted for commercial operation. So it's been incorporated into the original system as an upgrade if you like. Therefore it has to operate through the ADIRS system.
So dont turn off all the ADIRS and think you'ill still have GPS.

[oakhg]

Could GPS work independently without ADIRS in the real flight?