Hi Chris,

There is always the possibility that the PHA algorithm can get "fooled." Having more dense data (in space and time) would help, and probably help a lot, but it would not eliminate or make this aspect of the PHA infallible.

At the risk of over-generalizing before really thinking it through, I'd say that all quality assurance / quality control algorithms fit in this category. It's certainly been my experience that no QA routine is bulletproof.

Deke