Sistem Kedudukan Global atau GPS telah berjaya digunakan untuk menentukan posisi dan atitud kapal angkasa. Melalui kaedah pengiraan , posisi dan atitud satelit digambarkan melalui tesis ini. Pengiraan posisi dan atitud satelit dikirakan dan dipersembahkan melalui Graphical User Interface (GUI) dengan menggunakan MATLAB 7.0. Secara amnya, GUI ini akan menunjukkan posisi satelit dalam koordinat ECEF XYZ dan koordinat geodetik (latitud, longitud dan ketinggian), atitud satelit (yaw angle, pitch angle dan roll angle) dan teori asas GPS.
Posisi satelit ditentukan dengan mengetahui koordinat-koordinat satelit GPS dalam ECEF XYZ, jarak-jarak anggaran satelit dalam meter dan anggaran posisi-posisi penerima GPS dalam koordinat ECEF XYZ. Melalui tesis ini, penerima GPS akan mengesan empat satelit GPS di orbit dalam menetukan posisi satelit. Kaedah pengiraan menggunakan penukaran WGS_84 digambarkan.
Atitud satelit ditentukan dengan menggunakan tiga antena iaitu antena master dan dua antena slave. Menurut hubungan antara koordinat setempat dan koordinat rangka badan, formula yaw, pitch dan roll boleh diterbitkan secara langsung. Kaedah pengiraan untuk menentukan atitud satelit dengan mengetahui dua koordinat slave antenna digambarkan.
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Global Positioning System (GPS) has been used successfully to determine position and attitude of a spacecraft. A direct calculation method of position and attitude determination for a satellite is described. The satellite position and attitude is calculated and presented via the Graphical User Interface (GUI) by using the MATLAB 7.0. In general, this GUI will show the satellite position in ECEF XYZ coordinates and geodetic coordinates (latitude, longitude and altitude), satellite attitude (yaw angle, pitch angle and roll angle) and basic theory of GPS. The satellite position is determined by knowing the GPS satellite coordinates in ECEF XYZ, GPS satellite pseudoranges in meters and receiver position estimate in ECEF XYZ. In this thesis, the GPS receiver will detect four GPS satellites visible on the orbit in order to determine satellite position. A direct calculation method using the WGS-84 transformations is described. Satellite attitude is determined by using three antenna systems which are master antenna and two slave antennas. According to the relations between the local coordinates and the body frame coordinates, the formulas for computing yaw, pitch and roll can be derived directly. A direct calculation method to determine the satellite attitude by knowing the two local coordinates of the slave antennas are described.
Satellite attitude determination by using gps _Noor Rasyidah Wahidon_A2_2008_NI