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Nizam Ahmad
Pusat Pemanfaatan Sains Antariksa, LAPAN
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FLUKS DAN DISTRIBUSI PARTIKEL ENERGETIK DI ORBIT LEO PENYEBAB TERJADINYA ANOMALI SATELIT Nizam Ahmad; - Rasdewita K.
Jurnal Sains Dirgantara Vol 7, No 2 (2010)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3524.498 KB) | DOI: 10.30536/j.jsd.2010.v7.a1121

Abstract

The variation of satellite anomaly caused by the impact of energetic particle depends on the energy and particle fluxes distributed on the region of satellite placement. The determination on fluxes and particle distribution in low earth orbit was done by analyzing the satellite anomaly cases from the year of 2000 until 2009 and using particle data from NOAA 15 satellite. The analysis gives information about 6 anomaly cases occurred at high latitude, 3 cases at mid latitude dan 12 cases at low latitude. Most satellite anomaly cases caused by proton and electron simultaneously, wherein the flux order about 104 up to 106 particles/cm3 and the energy, E > 30 keV for electron and 80 litlle than E litlle than 240 keV for proton. This analysis also shows most anomaly cases were occurred on polar satellite at 23 local time. Keywords: Satellite anomaly, Proton, Electron
TELAH ORBIT SATELIT LAPAN-TUBSAT Nizam Ahmad; Thomas Djamaluddin
Jurnal Sains Dirgantara Vol 5, No.1 Desember (2007)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (450.03 KB) | DOI: 10.30536/j.jsd.2007.v5.a659

Abstract

The study of orbit characteristics of LAPAN-TUBSAT can be done by using some microsatellites which identical in the case of mission and its orbit. This knowledge is usefull to reduce the failure of mission. This characteristics can be seen from the change of orbital elements caused by perturbation forces. LAPAN-TUBSAT is placed in Low Earth Orbit (LEO) at altitude about 630 km which has orbit near polar (i≈98˚). At this altitude, the perturbations come from non-gravitation force such as atmospheric drag and gravitation force from earth oblatness. From the simulation can be predicted that in the early years of its operation, the variation in altitude and semi major axis is relatively small. The means that this satellite could have the life time more than 50 years. The effect of earth oblatness will cause the regression of the nodes of about 1˚/day and the rotation of the line of apsides of about -3˚/day. These changes are not too critical for near polar orbit which means that satellite keeps conducted the mission goal such as satellite imaging.
ANALISIS POTENSI ANOMALI SATELIT-SATELIT ORBIT RENDAH DALAM SIKLUS MATAHARI KE-23 [ANALYSIS OF POTENTIAL ANOMALY FOR LOW ORBITING SATELLITES IN SOLAR CYCLE 23] Nizam Ahmad
Jurnal Sains Dirgantara Vol 9, No 2 (2012)
Publisher : Lembaga Penerbangan dan Antariksa Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3201.35 KB)

Abstract

Analisis potensi anomali pada satelit-satelit orbit rendah bumi dapat dilakukan berdasarkan data anomali satelit dari operator satelit. Analisis ini menggunakan data bilangan sunspot (SSN), indeks F10,7, indeks Kp dan Dst serta data energi dan fluks partikel yang tersebar di orbit rendah bumi. Satelit-satelit yang berada dalam wilayah sebaran proton dan elektron diasumsikan berinteraksi langsung dengan partikel dan memberikan pengaruh yang bervariasi pada satelit. Analisis memperlihatkan bahwa kasus peluruhan orbit satelit dominan terjadi pada saat puncak aktivitas matahari, sedangkan kasus anomali satelit dominan terjadi pada tahun 2003. Analisis kejadian anomali juga memperlihatkan bahwa sistem kontrol sikap satelit paling rentan mengalami kerusakan. Identifikasi terhadap satelit-satelit yang belum diketahui penyebab anomalinya seperti Fuse (1), Fuse (2) dan Monitor-E memberikan informasi bahwa kemungkinan besar anomali dipengaruhi oleh peningkatan plasma ketika terjadi badai geomagnet. Anomali pada satelit Kirari, Obrview 3 dan HST diduga terkait dengan masalah pada sistem satelit sendiri. Analisis pada beberapa satelit yang digunakan untuk studi kasus seperti satelit Tiros 10, Landsat 5, Oceansat 1 dan CBERS 1 memberikan informasi bahwa semua satelit tersebut berpotensi mengalami anomali pada suatu waktu dan kebanyakan disebabkan oleh proton dan elektron dengan variasi fluks. Analisis potensi anomali ini sangat bermanfaat dalam membangun sistem peringatan dini gangguan operasional satelit-satelit Indonesia pada masa mendatang. Kata kunci: Anomali Satelit, Proton, Elektron
Co-Authors - Rasdewita K. Thomas Djamaluddin