High resolution workshop attracts international interest
By Terri Gregory, University of Wisconsin-Madison, SSEC
Fifty scientists from six different countries and sixteen research institutes converged on Madison, WI for the third annual Advanced High Spectral Resolution Infrared Observations Workshop. The Space Science and Engineering Center hosted the workshop at UW-Madison’s Friedrich Center on Lake Mendota’s shore from April 26–28. Attendees were treated to near perfect Wisconsin spring weather in an idyllic lakeside setting. Presentations given during the workshop are posted on the workshop’s web site.
SSEC organizes this annual workshop so that researchers new to this esoteric subject matter can learn from those more acquainted with the field. It also provides an opportunity to share engineering and scientific news and progress. Sessions devoted to the capabilities and requirements of new instruments elicited many questions and proffered new useful information. Those dealing with the Infrared Atmospheric Sounding Interferometer (IASI) and the Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) were particularly productive. Many scientists who attended the workshop contribute substantial input to the development of weather instruments used by meteorological agencies worldwide as well as techniques to exploit data from those instruments, so the workshop facilitates access to a wealth of experience and information.
IASI the sounding instrument on EUMETSAT’s first operational polar-orbiting weather satellite, is approaching launch and the instrument has passed all its tests. Researchers eagerly anticipate the data, which will be very accurate (temperature accuracy for data of 1 km resolution will be 1 Kelvin, within 10% for humidity). With spectral capability almost four times that of the Atmospheric InfraRed Sounder, the IASI will provide new information about clouds and trace gases.
The Space Dynamics Lab (SDL), with support from NASA and NOAA, has completed a preflight version of the Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS). Co-investigator Hank Revercomb (SSEC) introduced the instrument and itemized current instrument status. SDL, he said, has experience creating interferometer instruments. He emphasized this instrument’s unique internal calibration system, with blackbodies designed and constructed at SSEC. He and William L. Smith, GIFTS principal investigator, voiced what many researchers are thinking—GIFTS must fly! According to Revercomb, the instrument is necessary as part of a comprehensive testing program for the next generation GOES satellites. He noted that, because the instrument represents such a huge step technologically, everyone “will benefit if we can fly GIFTS and get it to a point where we can learn something.” The National Research Council’s Decadal Survey Interim report to congress said that GIFTS should be flown by 2008. Both Revercomb and Smith say it can be done.
Other key points from the meeting include:
Principal Component Analysis has been proved to be an extremely powerful diagnostic tool for high spectral resolution infrared instruments.
For absolute calibration, we need to measure differences of a tenth of a degree Kelvin. This level of calibration is important for climate studies. Very careful characterization and validation is important both before and after launch.
Foreign government, and U.S. corporate, federal and university institutions represented at the workshop included Moscow’s Scientific Research Center Planeta, the European Centre for Medium-Range Weather Forecasts, EUMETSAT, UK’s Met Office, Centre National d'Etudes Spatiales, the University of Oxford, Ball Aerospace, Atmospheric and Environmental Research (AER), Inc., Utah State University’s Space Dynamics Laboratory, NOAA’s National Environmental Satellite, Data, and Information Service, and several other groups.
The “International Hyperspectral Forum” was established near the end of the workshop to foster the exchange of information, data and ideas among the members of the hyperspectral community. The usefulness of the forum will be verified over the next few months. It is hoped that researchers with all levels of experience will continue the discussion, particularly those new to the field.