[IGSMAIL-0931] Meteorological Data Available from the CDDIS

[CDDIS/Carey]

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IGS Electronic Mail      Tue Apr 11  7:58:07 PDT 1995      Message Number 0931
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Author: CDDIS/Carey Noll 
Subject: Meteorological Data Available from the CDDIS

The CDDIS and GSFC VLBI staff have been looking into providing
meteorological data from global GPS stations collocated with VLBI antennas.
We have initiated procedures at GGAO (Greenbelt, MD), Fairbanks, Kokee
Park, and Westford to record met data during times when no VLBI observing
or testing is being done. These data are extracted from VLBI logs and
converted into RINEX format at the CDDIS.  The meteorological data provided
are dry temperature, relative humidity, and barometric pressure at 30
minute sampling intervals. The data are acquired and downloaded by the VLBI
site personnel on a best effort basis with typically a one to three day
delay.  The test data can be found on the CDDIS in the directory
GPS3:[GPSDATA.MET].  Once "operational", these data will be stored in the
same directory structure with the daily GPS observation and navigation data
files. 

The GSFC staff are very interested in hearing from the user community as to
the utility of these data.  We would like to know what frequency of
measurement, level of accuracy, and precision/resolution are required for
useful measurements.  We plan to make a general request to all global
collocated VLBI sites for this type of data once we hear from the user
community that these meteorological data sets are useful. Comments can be
directed to Carey Noll (noll at cddis.gsfc.nasa.gov). 


[Mailed From: Carey Noll 301-286-9283 <NOLL at CDDIS.GSFC.NASA.GOV>]