MATLAB based VHF and UHF amplitude scintillation characterization using the new low-latitude ionospheric tomography network (LITN)

Ionospheric scintillation has been studied intensively because it depreciates the satellite radio communication and navigational system performances. Scintillations are most severe at the equatorial anomaly region that corresponds to two belts, approximately 15oN and S of the magnetic equator. The Low-latitude Ionospheric Tomography Network (LITN) consists of ground stations extend at the northern latitude along ~120°E longitude. The LITN was established to focus on the equatorial anomaly dynamics. This study of the equatorial scintillation was achieved by examining the amplitude scintillation index S4. A computer application was designed to acquire and process data from the LITN to detect scintillation occurrences. Parameters such as amplitude scintillation index S4, elevation angle, satellite, date, time, receiver ground station, and geographical location are important for amplitude scintillation observation. Scintillation variations with operating frequency, local time, geographical location, solar and magnetic activity were observed. Ionospheric irregularity near the magnetic equator is associated with the Rayleigh-Taylor instability processes. Solar activity and magnetic activity result in the ionization and composition changes in the ionosphere

STEM Integrated Approach in Improving Students’ Physics Conceptual Understanding

The study on the Science, Technology, Engineering and Mathematics (STEM) integrated approach in improving students’ physics conceptual understanding in Indonesia was conducted following the quasi-experimental research design. Samples were determined using purposive sampling involving 30 students. The study sought to determine whether the STEM integrated approach can improve students’ physics conceptual understanding. Based on the findings, students agreed that the STEM integrated approach can improve physics conceptual understanding. Further, a significant difference in the scores of the students before and after the conduct of STEM integrated approach was observed and a significant relationship was obtained between students’ test scores and students’ level of agreement in the implementation of STEM integrated approach. Thus, the STEM integrated approach improved students’ physics conceptual understanding. It is recommended that seminars, workshops, and in-service training should be organized for effective implementation of the STEM integrated approach in the classroom

Matlab-based VHF and UHF amplitude scintillation characterization using the new low-latitude ionospheric tomography network (LITN)

The new LITN network was established in 2006 to study equatorial anomaly dynamics (Hsiao et al., 2009). It has ten Ionospheric Tomography Stations (ITS) placed along the 120°E longitude with stations in Japan, Taiwan, Philippines and Indonesia. These stations independently receive mutually coherent signals at VHF (150 MHz) and UHF (400 MHz) bands, which come from NNSS-like satellites and FORMOSAT-3/COSMIC satellites. Local ionospheric irregularities, that cause rapid fluctuations in radio signals or scintillation, can be studied using the total electron content (TEC) values acquired from the ITS receiver. In this study, a MATLAB-based application was developed to process these data for automatic identification and characterization of amplitude scintillation where six criteria are set to characterize an event as scintillation including the S4 index, elevation angle, transmitting satellite, confirmation from other data recording and ground stations, and location difference of the recordings. LITN data was obtained from August 2008 to February 2011. Scintillation varied with operating frequency, local time, geographical location, solar activity and magnetic activity. Strong scintillation occurred more in VHF than in UHF. Moreover, nighttime scintillations occurred predominantly around local midnight (2000∼0200 LT), while most of the daytime scintillation occurred at 0800∼1000 LT. Scintillation mostly occurred between 15°-25° of geomagnetic latitude and almost none below 10° and above 30° geomagnetic latitude. Generally, the scintillation occurred under quiet magnetic condition and the occurrence increases as the solar activity increases

VHF/UHF amplitude scintillation observed by the lowlatitude ionospheric tomography network (LITN)

Electron density irregularities in the ionosphere that cause rapid fluctuations in radio signals or scintillation has been studied using the Low-Latitude Ionospheric Tomography Network. The network uses Ionospheric Tomography System (ITS) receivers to retrieve VHF and UHF scintillation data from August 2008 to February 2011. Amplitude scintillation, which mostly occurred at the equatorial anomaly peak, varied with local time, solar activity and magnetic activity. Moreover, night-time scintillation occurred predominantly around local midnight (2100-0200 LT), while most of the daytime scintillation occurred at 0900-1500 LT. Generally, the scintillation occurred under quiet magnetic condition and the occurrence increases as the solar activity increases. © 2006-2015 Asian Research Publishing Network (ARPN)