Ionospheric Physics

A response of nonlinear optic of several salt solutions in external magnetic field has been studied. An altered magnetic field varies from 0 until 0,2T used to induce samples, and then change of polarization angle β is measured by polarizators, where the direction propagation of laser is perpendicular to the direction of B. Various concentration of solution is used at 5% until 35%. Our experiment shows that the graphs of β vs. B are still linear for mineral water and NaCl solution.

Had been done experiment about influence of external magnetic field toward polarization angle of laser ray to NaCl various concentration 5%,10%,15%,20%,25%,30%,35% and water. Optical characteristic behaviors studied in this research were vibration direction rotation of electric fields β β β β from

A close link between the atmospheric Intertropical Convergence Zone (ITCZ) and ionospheric plasma bubble has been proposed since the last century. But this relationship has often appeared to be less than convincing due to the simultaneous roles played by several other factors in shaping the global distribution of ionospheric bubbles. From simultaneous collaborative radar multibeam steering measurements at Kototabang (0.2°S, 100.3°E) and Sanya (18.4°N, 109.6°E), conducted during September–October of 2012 and 2013, we find that the total numbers of nights with bubble (i.e., occurrence rates) at the two closely located longitudes (Kototabang and Sanya) are comparable. But interestingly, the total number of nights with locally generated bubble (i.e., generation rate) over Kototabang is clearly more than that over Sanya. Further analysis reveals that a more active ITCZ is situated around the longitude of Kototabang. We surmise that the enhanced ionospheric bubble generation at Kototabang...

We investigate the geospace response to the 2015 St. Patrickˈs Day storm leveraging on instruments spread over Southeast Asia (SEA), covering a wide longitudinal sector of the low-latitude ionosphere. A regional characterization of the storm is provided, identifying the peculiarities of ionospheric irregularity formation. The novelties of this work are the characterization in a broad longitudinal range and the methodology relying on the integration of data acquired by Global Navigation Satellite System (GNSS) receivers, magnetometers, ionosondes, and Swarm satellites. This work is a legacy of the project EquatoRial Ionosphere Characterization in Asia (ERICA). ERICA aimed to capture the features of both crests of the equatorial ionospheric anomaly (EIA) and trough (EIT) by means of a dedicated measurement campaign. The campaign lasted from March to October 2015 and was able to observe the ionospheric variability causing effects on radio systems, GNSS in particular. The multiinstrumental and multiparametric observations of the region enabled an in-depth investigation of the response to the largest geomagnetic storm of the current solar cycle in a region scarcely reported in literature. Our work discusses the comparison between northern and southern crests of the EIA in the SEA region. The observations recorded positive and negative ionospheric storms, spread F conditions, scintillation enhancement and inhibition, and total electron content variability. The ancillary information on the local magnetic field highlights the variety of ionospheric perturbations during the different storm phases. The combined use of ionospheric bottomside, topside, and integrated information points out how the storm affects the F layer altitude and the consequent enhancement/suppression of scintillations.

Himawari-8 satellite cloud observation data covers all areas of Indonesia. The cloud observation data can be used for observations of current weather conditions and short-term predictions. This paper reports the verification method of Himawari-8 Observation Data using Cloud Optical Thickness (COT) and compared to Cloud Image Energy. The verification test was carried out to determine the accuracy of Himawari-8's observations. COT data were verified using energy data from the observation image of the time-lapse camera. First, the time-lapse camera captures and classifies the cloud image. Subsequently, the energy of each image frame was calculated and regrouped the result based on the energy to determine the type of the cloud. The results show that there is a positive correlation between COT and low energy values with cumulonimbus cloud detection, on the contrary for Cirrus-cloud type. However, the data requires a more accurate observation method to obtain data from cloud images on the Himawari-8 satellite, specifically for regions with a small spatial size of 4 km and thin clouds in the lower layer.

29 We investigate the geospace response to the 2015 St. Patrick's Day storm leveraging on 30 instruments spread over South East Asia (SEA), covering a wide longitudinal sector of the low 31 latitude ionosphere. A regional characterization of the storm is provided, identifying the 32 peculiarities of ionospheric irregularities formation. The novelties of this work are the 33 characterization in a broad longitudinal range and the methodology relying on the integration of 34 data acquired by GNSS receivers, magnetometers, ionosondes and Swarm satellites. This work is 35 a legacy of the project ERICA (EquatoRial Ionosphere Characterization in Asia). ERICA aimed 36 to capture the features of both crests of the Equatorial Ionospheric Anomaly (EIA) and Trough 37 (EIT) by means of a dedicated measurement campaign. The campaign lasted from March to 38 October 2015 and was able to observe the ionospheric variability causing effects on radio 39 systems, GNSS in particular. The multi-instru...

We have investigated the relationship between the maximum latitude extension of observed scintillations (Lmax) and the maximum altitude of the equatorial F-region bottomside (h’Fmax), peak of eastward electric field (Emax), and time duration of eastward electric field (TE) during PRE period in the equatorial region. We used three GPS receivers installed in Kototabang (0.2S, 100.3E; 10.0N magnetic latitude), Pontianak (0.02S, 109.3E; 8.9S magnetic latitude), and Bandung (6.9S, 107.6E; 17.5S magnetic latitude), Indonesia for observing scintillation activity in period 18.00-22.00 LT (LT=UT+7h) and two frequency modulated-continues wave (FM-CW) ionosondes installed near equator magnetic, Chumphon (10.7N, 99.4E; 3.3N magnetic latitude), Thailand and Bac Lieu (9.3N, 105.7E; 1.7N magnetic latitude), Vietnam for measuring PRE parameters, such as h’F, vertical drift (dh’F/dt) which indicates eastward electric field, and TE. Our observation period is during equinox months (March, April, Septe...

The western-equatorial meteor radar was installed at Kototabang on equatorial (0.20 o LS 100,32 o BT) and has been operational since 2002. It is used for observing meteor as they enter the Earth's atmosphere to provide the wind data profile in both zonal and meridional direction besides meteor echo rate data which have only one wide beam signal transmission vertically. MWR system hardware comprises two main components: The antenna system and feeders, and the radar system itself. The antenna system is typically composed of two-element Yagis for transmission and five 2-element Yagis for reception. The instrument cabinet contains all of the remaining elements of the MWR radar system i.e. the RF components and the data acquisition which equipped with a GPS-locked real time clock for accurate acquisition time stamps. Those mentioned above will be described in this paper about the radar system, along with the details of the experiment and analysis techniques. Also an initial results are presented, indicating the radar produces count rates around thousands meteors per day.

Space Science Center of Indonesian Institute of Aeronautics and Space called LAPAN has installed several solar radio receivers named CALLISTO in various parts of Indonesia. The equipment has made some solar radio observational data which is indicate solar radio burst since its operation. All of the observational data stored in the file format of Flexible Image Transport System (FITS) which is the raw data. Therefore, it is required a such kind of related data processing to produce a data that can be used for further research. In this paper will discuss how the observational data of CALLISTO could be generated included the information of data format, CALLISTO data processing techniques used in these activities as well as some of the data processing based on data indicating solar radio bursts. As the results, a map of solar radio spectrum as spectrograph profiles and some determinations of frequency drift base on the data will also be discussed in this paper. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Space Science Center of Indonesian Institute of Aeronautics and Space called LAPAN has installed several solar radio receivers named CALLISTO in various parts of Indonesia. The equipment has made some solar radio observational data which is indicate solar radio burst since its operation. All of the observational data stored in the file format of Flexible Image Transport System (FITS) which is the raw data. Therefore, it is required a such kind of related data processing to produce a data that can be used for further research. In this paper will discuss how the observational data of CALLISTO could be generated included the information of data format, CALLISTO data processing techniques used in these activities as well as some of the data processing based on data indicating solar radio bursts. As the results, a map of solar radio spectrum as spectrograph profiles and some determinations of frequency drift base on the data will also be discussed in this paper. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Beberapa metode penentuan estimasi DCB penerima GPS di Indonesia dan sekitarnya telah dibandingkan. Metode-metode tersebut adalah: (1) metode kuadrat terkecil dan (2) metode regresi linier kuadrat foF2 dengan TEC ionosfer dan (3) metode geometri satelit. Hasil estimasi DCB dengan menggunakan metode-metode tersebut divalidasi menggunakan DCB hasil perhitungan IGS. Makalah ini menjelaskan hasil perbandingan metode-metode tersebut dan menganalisis efisiensinya untuk pemodelan TEC ionosfer dari data GPS frekuensi ganda di Indonesia dan sekitarnya.

Abstrak Kejadian equatorial spread F (ESF) di Biak (01 o LS, 135 o BT) telah diteliti berdasarkan data harian selama Maret dan April tahun 1992 dengan kondisi "sunspot" sedang dalam bentuk laju pertumbuhan ketidakteraturan menggunakan mekanisme ketidakmantapan Gravitational Rayleigh-Taylor (GRT) yang meliputi instabilitas gravitasi dan persilangan antara medan listrik dan medan magnet. Statistik kejadian ESF di Biak telah diuji dalam hubungannya dengan variasi ketinggian maksimum h'F setelah matahari terbenam, kecepatan kenaikan h'F dan fluktuasi dari kenaikan tersebut. Selain itu juga dikaitkan dengan aktivitas matahari dan geomagnet. Didapatkan bahwa variasi harian kejadian ESF di Biak dapat dijelaskan dengan baik secara umum menggunakan dasar mekanisme GRT. Berdasarkan pada data Maret tahun 1992 -1995 kejadian ESF menurun dengan berkurangnya aktivitas matahari. Abstract The occurrence of equatorial spread F (ESF) at Biak BT) LS,135 01 ( o o

Hubungan antara frekuensi kritis lapisan F2 ionosfer (foF2) dengan total electron content (TEC) telah dimodelkan menggunakan data foF2 keluaran model sederhana ionosfer lintang rendah Indonesia (MSILRI) dan TEC yang diturunkan dari data GPS (Global Positioning System) stasiun BAKO yang terletak di Cibinong. Validasi model tersebut dilakukan dengan cara membandingkan prediksi foF2 dari TEC GIM/Global Ionospheric Map (disingkat foF2 GIM-MSILRI) dengan foF2 dari pengamatan ionosonda. Hasil validasi menunjukkan bahwa pada 1 Desember 2009, saat aktivitas matahari rendah prediksi foF2 GIM-MSILRI lebih rendah dari data pengamatan ionosonda untuk ionosfer belahan bumi utara terutama di lintang tinggi dan lebih tinggi untuk belahan bumi selatan. Dari nilai rata-rata mutlak simpangan foF2 GIM-MSILRI dengan pengamatan ionosonda di beberapa lintang yang berbeda, terlihat bahwa foF2 GIM-MSILRI untuk belahan bumi selatan lebih akurat dibandingkan dengan prediksi model foF2 di belahan bumi utara. Di belahan bumi bagian selatan simpangan model bervariasi dari 0,52 -0,85 MHz sementara di belahan bumi bagian utara simpangan model bervariasi dari sekitar 0,65 sampai 1,12 MHz. Setelah terjadi coronal mass ejection (CME) pada 28 dan 29 Oktober 2003, model foF2 GIM-MSILRI dapat menangkap dengan baik badai ionosfer positif berupa peningkatan foF2 di atas Tanjungsari beberapa saat setelah CME sampai di magnetosefer bumi. Walaupun foF2 GIM-MSILRI dapat mengikuti badai ionosfer negatif berupa penurunan nilai foF2 beberapa jam setelah terjadi badai geomagnet tetapi model memprediksi foF2 lebih tinggi dari pengamatan.

Model Sederhana Ionosfer Regional Indonesia (MSIRI) adalah modifikasi dari simplified ionosheric regional model (SIRM) yang awalnya dikembangkan untuk pemodelan karakteristik ionosfer yang paling cocok di atas Eropa yang digunakan untuk keperluan komunikasi radio. Model tersebut yang didasarkan pada ekspansi Fourier dari sekumpulan data yang telah lalu memiliki kesesuaian yang baik di daerah lintang tengah. Makalah ini menerangkan pemodelan MSIRI berdasarkan data ionosfer di daerah lintang rendah di sekitar Indonesia: Manila, Singapura, Vanimo dan Darwin, untuk dua parameter ionosfer penting yang diperlukan dalam penentuan MUF (maximum usable frequency) yaitu foF2 dan M(3000)F2. Hasil MUF yang ditentukan dari MSIRI juga dibandingkan dengan pengamatan MUF menggunakan ionosonde oblique Sumedang-Manado.

Abstrak. Ionosfer mempengaruhi gelombang elektromagnetik yang melewati lapisan tersebut dengan menginduksi suatu tambahan waktu tunda transmisi. Dalam penentuan posisi dan navigasi dengan GPS, gangguan ionosfer telah menjadi sumber kesalahan terbesar setelah kesalahan yang bersumber dari Selective Availability (SA) tidak diaktifkan. Untuk penentuan posisi presisi tinggi dengan GPS pengaruh ionosfer harus diestimasi sehingga koreksi ionosfer dapat ditentukan untuk mengeliminasi pengaruh ionosfer pada pengamatan GPS. Dalam penetuan posisi dengan GPS frekuensi tunggal koreksi ionosfer dapat diperoleh dari TEC yang dihitung dari data GPS dual frekuensi stasiun referensi atau dari model. Makalah ini menjelaskan metode penentuan dan pemodelan TEC dari data GPS stasiun tetap yang ada di Indonesia dan sekitarnya. Model TEC spasial pada jam tertentu diestimasi menggunakan fungsi polinom. Variasi diurnal koefisien model polinom pada setiap jam mulai pukul 00.00 -23.00 UT diestimasi menggunakan ekspansi Fourier. Kata kunci: GPS; bias ionosfer; kombinasi kode dan fase; total electron content; kalibrasi; model; regional.

The effect of the ionosphere on the propagation of signals emitted from GPS satellites at an altitude of about 20,000 km is in the form of code delay or carrier advance of the signal propagation time which depends on the Total Electron Content (TEC) and the GPS signals frequency. Coronal Mass Ejections (CMEs) occurred during October 28 and 29, 2003 solar storms have caused ionosphere disturbances called ionospheric storms. The ionospheric storms have degraded the accuration of single frequency GPS absolute positioning to more than 400%. Mitigation of ionospheric storms effect on the single frequency GPS absolute positioning by using Klobuchar model can not produce a significant increase in accuracy. Hence during the ionospheric storms, the regional ionospheric TEC model is needed for ionospheric correction of single frequency GPS absolute point positioning.