RAIM errors and the Apollo GPS

We've been getting RAIM errors in Southern and Central California with
our GX60 in the past couple of months. The unit recovers in a minute
or so and there doesn't seem to be a pattern (e.g. in a turn, special
altitudes) to the failures. Yes, I know about the earlier discussions
of RAIM error and the GX** but it seems like the frequency is
increasing dramatically. I also note that there are more NOTAMS for
GPS "outages" that sometimes reach our area, 'tho they don't seem to
correlate well with the errors I get. I assume its the military trying
to learn how to jam GPS.

My specific questions:

1) Does anybody else see more RAIM errors than, e.g. a year ago? What
manufacturer/times/places?

2) Do the military interruptions (or whatever is the source of the
NOTAMS) usually last a few minutes?


Lee Elson