#CHRISTY
	#TTS (channel 3)  around 220 hPa (~10 km or 1-35 km).
	#Douglass: T2LT mean altitude 2.5 km (about 740 hPA);  
	#T2 - mean altitude 6.1 km) 466 hPa
		#http://www.sensorsone.co.uk/altitude-pressure-units-conversion.html 
       #effective T2LT altitude is 2.5 km, about 750 hPa (Christy)
	#TLS is centered around 75 hPa (~20 km or ~14-50 km) and TTS (channel 3)  around 220 hPa (~10 km or 1-35 km).

 	#url<-"ftp://ghrc.nsstc.nasa.gov/pub/data/msu/t2lt/uahncdc.lt"#obsolete
#readme: http://vortex.nsstc.uah.edu/data/msu/t2lt/readme.06Jul2009
# reference period is 1979-1998: see readme, Kuly 13, 1999

	#url<-"ftp://ghrc.nsstc.nasa.gov/pub/data/msu/t2lt/uahncdc.lt"#obsolete
#	url="http://vortex.nsstc.uah.edu/data/msu/t2/uahncdc.mt"

###tropo  - t2lt

get_uah=function(tropo) {
	#  tropo="t2lt"
 	alias=c(t2lt="lt",t2="mt")
	name0=c("year","mo",c(t(outer(c("GLB","NH","SH","Trpcs","NoExt","SoExt","NoPol","SoPol"),c("","_land","_ocean"),function(x,y) paste(x,y,sep="")))),"USA48")
	loc=paste("http://vortex.nsstc.uah.edu/data/msu/",tropo,"/uahncdc.",alias[tropo],sep="")
 	fred=readLines(loc);N=length(fred)
	fred=fred[1:(N-5)]
	writeLines(fred,"temp")
 	msu<-read.table("temp",header=TRUE,nrow= N-5)
	msu<-ts(msu,start=c(1978,12),freq=12)
 	dimnames(msu)[[2]]=name0
	return(msu)
}