Instruments currently used to measure the
height and thickness of the outer part of the earth’s atmosphere
– the ionosphere – could be upgraded to provide more
accurate measurements, Bill Wright of NOAA‘s
National Geophysical Data
Center told attendees of the American
Geophysical Union‘s fall
meeting in San Francisco today.
The instruments – ionosondes –
have been well established in high frequency (HF) communications,
aeronomy, and space weather and have contributed to a 50-year
climate record and much of our basic knowledge of the thermosphere.
"A loosely coordinated global network of some 120 instruments
continues to provide classical parameters such as critical frequencies,
some altitude data, and HF propagation variables, but these fail
to express much of the information latent in basic sounding data,"
Wright said.
A very few research ionosondes make more
sophisticated measurements, Wright said. "Accurately digitized
echo complex amplitudes are retained at high time and frequency
resolution from a small array of receiving antennas. Echos are
recognized and discriminated from impulsive noise."
Wright and his co-author, Terry Bullett
of the Air Force Research Laboratory at Hanscomb Field, Mass.,
said that many of the monitoring ionosondes operating today could
be upgraded at modest cost to yield additional information that
is vital to our understanding of the ionosphere.
More information on the ionosphere is available
at http://www.ngdc.noaa.gov/stp/stp.html
Scroll down on the left. Click on "Ionosphere."
