Google led me to a paper written 10 years ago at by some folks at Lincoln Labs that determined the GPS-rain delay value experimentally. The paper is at
http://gauss.gge.unb.ca/papers.pdf/ion96am.anthea.pdf and the results are up to 300 mm of delay to a GPS signal caused by rain at MIT Haystack observatory and a few nearby places. That's on the order of one nanosecond, so it's not much delay in the big scheme of things. But there are places with more water in the air than Boston, as has been pointed out. I think Seattle may qualify from time to time. I personally can't offer much experimental data, since we haven't had measurable rain in Tucson for six months now. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts