The Global Positioning System (GPS) satellite constellation was developed for precise navigation and positioning. The GPS today consists of 28 satellites that transmit L-band radio signals. Other global navigation systems are under development and will greatly increase the amount of future satellites. A receiver on the ground can measure with high precision the phase delays of the GPS radio signal caused by the ionosphere and the neutral atmosphere. From these measurements, we can derive total electron content and atmospheric water vapor along the ray path between the GPS satellites and a ground-based receiver. A receiver on board a low-Earth orbiting satellite can provide vertical profiles of electron density, neutral atmosphere bending angles and refractivity. Over the past decade we have witnessed significant progress in the science and technology of both ground-based and space-based atmospheric remote sensing. The ground-based and space-based GPS atmospheric sensing data are expected to have a major impact on climate monitoring, global and regional weather prediction, ionospheric research, and space weather forecasting. This two-week colloquium is intended to provide students with an overview from the basic GPS atmospheric measurements to their applications in weather prediction, climate analysis, and ionospheric research. Courses to be presented in the colloquium will include: physics of microwave propagation, principles of the Global Positioning System, precipitable water vapor and slant-path GPS water vapor sensing, radio occultation, assimilation of GPS measurements, analysis of results from recent GPS radio occultation missions, applications of GPS data in numerical weather prediction, ionospheric research, space weather, and climate analysis, and development of advanced techniques such as the cross-link technology.

Program: Please go to the Colloquium's Agenda for more information.

Lecturers: Leading scientists and experts in the fields of space-based and ground-based GPS atmospheric remote sensing and their scientific applications will be invited to give lectures. List of invited lecturers will be posted and updated on the web.

Organization: Mornings and most afternoons will be devoted to formal lectures with ample time for discussion among the lecturers and participants. Some afternoons will be spent on interactive exercises, exploratory research projects and student presentations. The colloquium is being organized by Y.-H. Kuo (NCAR/UCAR), C. Rocken (UCAR), S. Sokolovskiy (UCAR), E. R. Kursinski (U. Arizona), and G. Hajj (JPL).

Participants and Support: Support will be provided for selected graduate students in the Atmospheric Sciences or a closely related field; recent recipients of a Ph.D. may also be supported. Sponsored participants will receive support for actual travel costs (not to exceed coach airfare), dormitory housing at the University of Colorado, bus transportation between the dormitories and colloquium site, and a modest per diem. A limited number of unsponsored participants may be selected as space allows. Unsponsored participants must make their own arrangements for transportation and housing costs. The planning office will help with housing and reservations at the dormitory, if desired.

Field Trips: Under the sponsorship of the NSF International Programs, a special field trip will be organized to visit key GPS atmospheric remote sensing facilities in Taiwan and Japan for selected U.S. students, during the period of 3 - 14 July 2004. These facilities include the National Space Program Office in Taiwan, the Meteorological Research Institute and the Geological Survey Institute of Japan.

Applications should provide:

1. A letter describing your interest in the colloquium topic and how it relates to your research interests.
2. A statement indicating specific financial support requested. If participants have some funding support from their home institution, it should be indicated in the application.
3. Transcripts (unofficial acceptable) for graduate courses, dates and institutions for receipt of degrees, names of research advisor and dissertation abstract or topical outline.
4. Two letters of recommendation, including one from your thesis advisor, sent directly to NCAR.

For researchers who would like to attend the colloquium as unsponsored participants, they should provide:

1. A letter describing their research projects and how it relates to the topics of the colloquium.
2. A resume.

For participants who are U.S. citizens or permanent residents and interested in attending the special field trip please indicate so on the application.

Applications and recommendations must be received by the extended deadline of April 30th, 2004. Selected participants will be notified by May 10th, 2004.

Send applications and letters of recommendation to:
Mr. Scott Briggs
Advanced Study Program
National Center for Atmospheric Research
P.O. Box 3000
Boulder, CO 80307-3000

Or by email (sbriggs@ucar.edu) Fax (303-497-1646), express mail (1850 Table Mesa Drive, Boulder, CO 80305, phone: 303-497-1607) or through the colloquium website (www.asp.ucar.edu/colloquium/2004).

The National Center for Atmospheric Research (NCAR) is operated by the non-profit University Corporation for Atmospheric Research (UCAR) under the sponsorship of the National Science Foundation.