[teqc] Re: cycle slips

Lou Estey lou at unavco.org
Fri Mar 26 12:46:57 MDT 2010


hi Nacho,

> i am investigating a sudden rise and drop in cycle slips in my region.
>  From your experience is a sudden rise of cycle slips over a region
> limited to increased Iono activity or could the teqc values be pointing
> in a different direction? many RINEX from many different receiver
> vendors show the increase and then drop at the same time. Thanks for any
> hints.

Well, we're coming out of the latest solar minimum -- I don't know exactly
where we are at the moment because I don't follow that closely, but this
plot from NASA shows the solar activity (as measured indirectly by sunspot
density) could be coming on strong any time now:

http://en.wikipedia.org/wiki/File:Sunspot-bfly.gif
http://solarscience.msfc.nasa.gov/SunspotCycle.shtml

so, yes, if that's the case, then we could expect to see sudden sharp
increases in slips due to ionospheric activity.  (Detecting and reporting
such slips was one of the original motivations for the qc of GPS data
in the late '80s and early '90s by Chris Rocken, Chuck Meertens, and
others at UNAVCO at the time.)

Maybe someone who more closely follows space weather could comment.
http://solarcycle24.com/ shows various measures in the last hours or
days (depending on the observable).  Is there a nice summary of activity
showing details of the last few months somewhere?

cheers,
--lou

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Louis H. Estey, Ph.D.              office:  [+001] 303-381-7456
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