Useful site references for verification of satellite data
ftp://podaac.jpl.nasa.gov/pub/ - archives and in near real time altimeter data and others
http://lwf.ncdc.noaa.gov/oa/pub/data/ghcn/v2/ghcnftp_zipd.html - archives of metheorological observations.
http://raob.fsl.noaa.gov - archive of in real time aerological data
http://www.poi.dvo.ru/eng/base/index.shtml - POI FEB RAS data base