Free Space Attenuation Analysis for X -band and S-band Satellite Link using Meteorological Radar Data in the Tropics

Free space fading for satellite link propagation studies in the equatorial regions are indeed particularly scarce, complicated and expensive to venture upon. Most of satellite propagation studies done in temperate climate are not reasonable for countries in the equatorial region due to its huge climate differences. In equatorial regions, the future stratospheric and space-based telecommunications systems are expected to operate with high elevation angle slant paths and high frequency of operation from the Earth stations’ point of view. These systems will also be sharing frequency bands with other terrestrial and space services. From this standpoint, a precise modelling of the vertical variation of free space path loss parameters will be of great interest for improving the prediction of the clear sky margin along the slant path in the tropics. In this paper, the Free Space Path Loss (FSPL) propagation link for Xband and S-band RazakSAT satellite will be analysed using a Terminal Doppler Weather Radar (TDWR) data. Both links will be evaluated and the assessment of the link’s fade margin will be suggested. An accurate estimation of the satellite fade margin will evidently save power from the satellite perspective and better transmission can be estimated. The outcome of this research will be very useful for future implementation of satellite link fade margin improvement during non-rain weather, both during clear sky and cloudy weather in the tropical region. This research will facilitate the key decision makers and the satellite designers to progress business, availability, and throughput proficiently. Therefore, hopefully, the spending is well reasonable with a better return on investment (ROI) and attracts more investors in satellite industries

Kepelbagaian warisan geologi persisiran pantai di Kepulauan Langkawi

Langkawi is known internationally as one of the main tourist destination in Malaysia, blessed with earth heritage that has great potential to be develop in a sustainable manner. Knowledge of the diverse physical heritage (geology and landscape) found along the coast plays an important role to unravel its potential as a new product of tourism. Coastal landscape is characterised by rocky, pebbly, sandy and muddy (including mangrove) beaches together with small islands. The rocky beach unfolds a diverse range of rocks and earth features, in which retains the historical record of the origin of Malaysia Land that took place 550. It also reveals the coastal landscape formation which crafted by waves activities. A section of the coastal outcrop represent a unique historical site and scenic landscape. This paper illustrates the diverse geological heritage and landscape found in Datai and Burau Bay and introduces rocky beach as a prospect, in which a major component of the environment, for development of beach resources

Rare-earth elements modelling of the Langkawi granites

Based on the REE patterns the Langkawi granites can be divided into two groups i.e. the Gunung Raya-Dayang Bunting granite and Kuah-Pulau Tuba granite. The Gunung Raya-Dayang Bunting granite has weak negative Eu anomalies whereas the Kuah-Pulau Tuba granite has moderately strong negative Eu anomalies. Rb/Sr ratios also show similar differences with Rb/Sr ratios in Kuah-Pulau Tuba granites being much higher than those of the Gunung Raya-Dayang Bunting granite. Examination of the REE patterns shows that they have the usual 'bird-wing' shape with weak to moderately strong negative Eu anomalies. This pattern is similar to the West coast S-type granites and is different from the I-type granites of the East coast. A possible source material for the Langkawi granite is the Cambrian sediments of the Machinchang Formation. Modelling of the REE pattern has been carried out in two stages namely batch melting and fractional crystallisation. Results show that the Gunung Raya-Dayang Bunting magma requires a slightly higher degree of partial melting fraction (0.15-0.25%) compared to the Kuah-Pulau Tuba magma (0.25-0.3%). On the other hand the Gunung Raya­/Dayang Bunting magma has undergone a higher degree of fractionation (16%) compared to the Kuah-Pulau Tuba magma (9%)

Free space attenuation analysis for X -band and S-band satellite link using meteorological radar data in the tropics

Free space fading for satellite link propagation studies in the equatorial regions are indeed particularly scarce, complicated and expensive to venture upon. Most of satellite propagation studies done in temperate climate are not reasonable for countries in the equatorial region due to its huge climate differences. In equatorial regions, the future stratospheric and space-based telecommunications systems are expected to operate with high elevation angle slant paths and high frequency of operation from the Earth stations’ point of view. These systems will also be sharing frequency bands with other terrestrial and space services. From this standpoint, a precise modelling of the vertical variation of free space path loss parameters will be of great interest for improving the prediction of the clear sky margin along the slant path in the tropics. In this paper, the Free Space Path Loss (FSPL) propagation link for Xband and S-band RazakSAT satellite will be analysed using a Terminal Doppler Weather Radar (TDWR) data. Both links will be evaluated and the assessment of the link’s fade margin will be suggested. An accurate estimation of the satellite fade margin will evidently save power from the satellite perspective and better transmission can be estimated. The outcome of this research will be very useful for future implementation of satellite link fade margin improvement during non-rain weather, both during clear sky and cloudy weather in the tropical region. This research will facilitate the key decision makers and the satellite designers to progress business, availability, and throughput proficiently. Therefore, hopefully, the spending is well reasonable with a better return on investment (ROI) and attracts more investors in satellite industries