| NOAA 2000-089 FOR IMMEDIATE RELEASE Contact: Pat Viets 12/15/00 |
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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." |