In this paper, we present a comprehensive study of occurrence of L‐band scintillation in association with the appearance of sporadic E (Es) along the magnetic dip equator during daytime in 2013. The presence of L‐band scintillation was determined from signals collected with GNSS (Global Navigation Satellite Systems) ground‐based Scintillation Network Decision Aid receivers from five stations situated at the magnetic dip equator. The detection and analysis of Es layers were obtained from GNSS FORMOSAT‐3/Constellation Observing System for Meteorology, Ionosphere, and Climate (F3/C) radio occultation (RO) data. Combining ground‐based data with the limb‐viewing geometry from space provides a unique opportunity to retrieve complementary information about scintillation and association with equatorial E region irregularities (i.e., Es) during daytime. Results for the first time show that daytime scintillation does occur at the magnetic dip equator and the occurrence is associated with the appearance of Es observed using GNSS F3/C RO data.

This paper presents an efficient hardware architecture of Prewitt edge detection for high speed image processing applications. The hardware design is implemented by using Verilog hardware description language, whereas the software part is developed by using Matlab. The zero computational error analysis indicates that the proposed architecture produces similar outputs with ideal result obtained by Matlab software simulation. The architecture is capable of operating at a clock frequency of 145 MHz at 550 frames per second (fps), which implies that the system is suitable for both image processing and computer vision applications.

Observations made in non-equatorial regions appear to support the hypothesis that the daytime scintillation of radio signals at gigahertz (GHz) frequencies is produced by the gradient-drift instability (GDI) in the presence of a blanketing sporadic E (E sb ) layer. However, the only evidence offered, thus far, to validate this notion, has been some observations of E sb in the vicinity of GHz scintillations. A more comprehensive evaluation requires information about electric field, together with the presence of a steep gradient, which is presumed to be that of E sb . In this regard, the region in the vicinity of the equatorial electrojet (EEJ) appears to be an ideal “laboratory” to conduct such experiments. The dominant driver of electron drift there is the same as that of the EEJ, the vertical polarization electric field, and indications are that the presence of E sb in that vicinity is controlled by a balance in horizontal transport of E sb , between the EEJ electric field and the neutral wind, as described in a model by Tsunoda (On blanketing sporadic E and polarization effects near the equatorial electrojet, 2008). In this paper, we present, for the first time, results from a comprehensive study of daytime GHz scintillations near the magnetic equator. The properties, derived from measurements, are shown, for the first time, to be consistent with a scenario in which E sb presence is dictated by the Tsunoda model, and the plasma-density irregularities responsible for GHz scintillations appear to be produced by the GDI.

Ionospheric scintillation can cause serious effects on communication systems, therefore the study of ionospheric scintillation is very crucial especially in the equatorial region where scintillation activity is maximum. The paper presents the month-to-month variations of amplitude and phase scintillations over Malaysia for a period of nine months from January to September 2010. The scintillation parameters are measured by the GPS ionospheric scintillation and TEC monitor (GISTM) using a dual-frequency GPS receiver at UKM, Malaysia (2.55°N, 101.46°E). The observations during the solar minimum show daytime amplitude scintillations were observed in the months of January and February with maximum value of S4 index between 0.2 and 0.3, from 10:00-14:00 LT, while phase scintillations were rarely observed. Nighttime amplitude scintillations were observed in March and August with maximum value of S4 index in the range of 0.2-0.4 at 22:00-24:00 LT and usually occurred with phase scintillations. It was found that amplitude scintillations rarely occurred at daytime but occurred frequently during nighttime.