1. 제목 : Tracking GPS Above GPS Satellite Altitude:


Results of the GPS Experiment on the HEO Mission Equator-S


2. 연사 : Prof. Guenter W. Hein (Institute of Geodesy and Navigation,


University FAF Munich, Germany)


3. 일시 : 1999년 12월 1일 (수요일) 16:00∼17:00


4. 장소 : 301동 1409-1호


5. 내용 :


Within the framework of the Small Satellite Mission Equator-S (launched on Dec. 2, 1997 with an Ariane 4 rocket) it could be demonstrated that it is possible to use GPS even in the vicinity of the geostationary orbit. The maximum altitude whre the GPS receiver provided measurements was about 61 000 km which constitutes a world record.


The GPS experiment was developed with funding of the German Aerospace Center (DLR), by the Institute of Geodesy and Navigation (IfEN) of the University FAF Munich, the German Space Operations Center (GSOC) of DLR in Oberpfaffenhofen, and by the Munich based aerospace company Kayser-Threde GmbH. The experiment data have significant impact for the future use of GPS receivers on-board of geostationary satellites.


In the past GPS receivers have only been used well below the orbital altitude of the GPS satellites (20 000 km). The reception of signals at larger altitudes could now be demonstrated within the Equator-S GPS experiment. As part of this, GPS signals have also been received from the antenna side lobes of the GPS satellites. The Motorola GPS receiver has originally been designed for use on low Earth orbits. It employs two antennas, which, incase of Equator-S, are aligned with the spacecraft s spin axis. In order to allow a signal reception up to the peak altitude of 61 000 km under these conditions, the receiver had to be manually operated from GSOC. For each part of the orbit the trackable GPS satellites were determined using a specially designed software and manually assigned to the various receiver channels.


The lecture focuses on the results especially in high altitudes and the problems that have been encountered by using a receiver designed for a LEO orbit, and it gives a short descrioption of the experiment as far as it is necessary to interpret the results.


6. 연사 약력 :


1973 Dipl.-Ingenieur for Geodesy, Technical University of


Darmstadt, Germany


1976 Ph.D. in Geodesy, Technical University of Darmstadt,


Germany


1976-1983 Assistent, Senior Assistent, Institute of Physical


Geodesy, Technical University of Darmstadt, Germany


1981 Habilitation (second Ph. D.) in Geodesy and Satellite


Geodesy, Technical University of Darmstadt, Germany 83-


now Full Professor and Director of the Institute of


Geodesy and Navigation, University FAF Munich


1990 Official Professorship offer (Geodesy) from the


University of Karlsruhe, Germany


1995 Official Professorship offer (Navigation) from the


University of Stuttgart, Germany


1997-1999 Dean of Faculty


7. 연락처 : 기계항공공학부 기창돈 교수 (전화 : 880-1912)