Rain Height Statistics from Spaceborne Radar for Satellite Communication in Malaysia

2012 ◽  
Vol 58 (1) ◽  
Author(s):  
Nor Azlan Mohd Aris
Keyword(s):  
Satellite Communication ◽  
Tropical Rainfall Measuring Mission ◽  
Rain Attenuation ◽  
Peninsular Malaysia ◽  
Equatorial Region ◽  
Radiowave Propagation ◽  
Tropical Region ◽  
Propagation Modeling ◽  
Bright Band ◽  
Communication Links

Tropical and equatorial region exhibit significantly higher rainfall compared to the temperate region leading to higher attenuation for satellite communication links. One of the issues in radiowave propagation modeling is the different precipitation structures which play an important role in the estimation of rain fade. However, few results on rain height over Malaysian equatorial stations have been presented so far. To this aim, an investigation on rain height derived from Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) is carried out. In this paper, the bright–band heights (hBB) have been analyzed to obtain monthly average values of the rain height (hR). TRMM PR is one of the most powerful instruments able to observe vertical profiles of rainfall. The analysis covers stratiform events around peninsular Malaysia. It is well known that hBB exists slightly below the 0°C isotherm height (h0) and this may lead to the estimation of rain height (hR). The obtained results on rain height are then compared with radiosonde observations and ITU–R Recommendation P.839–3. It is found that the bright–band height (hBB) appears to vary throughout the year and will mostly lie between 4192 m and 4593 m above mean sea level. The results suggest that by carefully consider the physical information of rain height derived from the various local databases should lead to substantial improvements in the rain attenuation prediction accuracy for equatorial and tropical region.

scholarly journals Analysis of Time Diversity Gain for Satellite Communication Link based on Ku-Band Rain Attenuation Data Measured in Malaysia

2018 ◽  
Vol 8 (4) ◽  
pp. 2608
Author(s):  
Islam Md. Rafiqul ◽  
Ali Kadhim Lwas ◽  
Mohamed Hadi Habaebi ◽  
Md Moktarul Alam ◽  
Jalel Chebil ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Satellite Communications ◽  
Earth Satellite ◽  
Rain Attenuation ◽  
Diversity Gain ◽  
Communication Link ◽  
Time Diversity ◽  
Communication Links ◽  
System Time ◽  
Diversity Technique

<p><span>This paper reports a study on mitigation of propagation impairments on Earth–space communication links. The study uses time diversity as a technique for mitigating rain propagation impairment in order to rectify rain fade. Rain attenuation time series along earth-to-satellite link were measured for two years period at 12.255 GHz in Malaysia. The time diversity technique was applied on measured rain fade to investigate the level of possible improvement in system. Time diversity gain from measured one-minute rain attenuation for two years period was estimated and significant improvement was observed with different delays of time. These findings will be utilized as a useful tool for link designers to apply time diversity as a rain fade mitigation technique in Earth-satellite communications systems.</span></p>

scholarly journals A Survey of Rain Fade Models for Earth–Space Telecommunication Links—Taxonomy, Methods,and Comparative Study

2021 ◽  
Vol 13 (10) ◽  
pp. 1965
Author(s):  
Md Abdus Samad ◽  
Feyisa Debo Diba ◽  
Dong-You Choi
Keyword(s):  
Electromagnetic Waves ◽  
Satellite Communication ◽  
Prediction Models ◽  
Measurement Techniques ◽  
Rain Attenuation ◽  
Data Sets ◽  
Tropical Regions ◽  
Earth Space ◽  
Propagation Modeling ◽  
Attenuation Models

Satellite communication is a promising transmission technique to implement 5G and beyond networks. Attenuation due to rain begins at a frequency of 10 GHz in temperate regions. However, some research indicates that such attenuation effects start from 5–7 GHz, especially in tropical regions. Therefore, modeling rain attenuation is significant for propagating electromagnetic waves to achieve the required quality of service. In this survey, different slant link rain attenuation prediction models have been examined, classified, and analyzed, and various features like improvements, drawbacks, and particular aspects of these models have been tabulated. This survey provides various techniques for obtaining input data sets, including rain height, efficient trajectory length measurement techniques, and rainfall rate conversion procedures. No survey of the Earth–space link models for rain attenuation is available to the best of our knowledge. In this study, 23 rain attenuation models have been investigated. For easy readability and conciseness, the details of each model have not been included. The comparative analysis will assist in propagation modeling and planning the link budget of slant links.

scholarly journals Characterization of Ka-band Radar Observations for Different Rain Types over Akure, Nigeria

2020 ◽  
pp. 9-19
Author(s):  
Joseph S. Ojo ◽  
Babatunde A. Alabi ◽  
Moses O. Ajewole
Keyword(s):  
Vertical Profile ◽  
Rain Rate ◽  
Quantitative Estimation ◽  
Radiowave Propagation ◽  
Propagation Path ◽  
Tropical Region ◽  
Fall Velocity ◽  
Ka Band ◽  
Stratiform Rain ◽  
Bright Band

Radar is a unique tool that can measure precipitation parameters over a large aerial coverage. Its application spans over study of climate change and radiowave propagation. Inter-relation between the rain parameters can also be derived with the height of radar especially on vertical profiling or aloft ground level. Hence effect of precipitation parameters can be assessed along the satellite propagation path with the help of space-borne radar. Satellite communication links operating at frequencies above 10 GHz are usually affected by hydrometeors especially rainfall. These effects are expected to be quite severe in the tropical region like Akure due to the nature of precipitation which is mainly convective and stratiform rain type. Therefore, information on vertical rain structure is important for precise quantitative estimation of precipitation. Thus, the focus of this work is to characterize the vertical profile of rain structures using vertically-pointing Ka-band Micro Rain Radar (MRR) at Akure, Nigeria. This has been achieved by using 2-year (2013 and 2014) data of rain parameters namely: rain rate, reflectivity, liquid water content and fall velocity obtained from MRR to determine the bright band heights under different rain types and its implications on satellite and radio waves propagation in this region. Rain rate in this region has been categorized into four groups namely: 0.02- 0.2 mm/h, 0.2- 2 mm/h, 2-40 mm/h, and 40 - 200 mm/h. The very low rain rate group is related to the stratiform rain types whereas highest rain rate groups are for the convective rain type. Study shows that parameters that are much associated with rain attained peak value at different height depending on the period of the year. The vertical profile of Z shows peak around 3 to 4.2 km height. The peak region is associated with the bright band height and contribution to the melting layer. This study revealed that the occurrence of bright band heights varies with rain types. The overall results will be useful for determining rain height needed for the prediction of rain attenuation in this region.

scholarly journals Single-Satellite Integrated Navigation Algorithm Based on Broadband LEO Constellation Communication Links

2021 ◽  
Vol 13 (4) ◽  
pp. 703
Author(s):  
Lvyang Ye ◽  
Yikang Yang ◽  
Xiaolun Jing ◽  
Jiangang Ma ◽  
Lingyu Deng ◽  
...  
Keyword(s):  
Real Time ◽  
Satellite Communication ◽  
The State ◽  
Earth Orbit ◽  
Integrated Navigation ◽  
Location Services ◽  
The Real ◽  
Navigation Algorithm ◽  
Communication Links ◽  
Leo Satellite

With the rapid development of satellite technology and the need to satisfy the increasing demand for location-based services, in challenging environments such as indoors, forests, and canyons, there is an urgent need to improve the position accuracy in these environments. However, traditional algorithms obtain the position solution through time redundancy in exchange for spatial redundancy, and they require continuous observations that cannot satisfy the real-time location services. In addition, they must also consider the clock bias between the satellite and receiver. Therefore, in this paper, we provide a single-satellite integrated navigation algorithm based on the elimination of clock bias for broadband low earth orbit (LEO) satellite communication links. First, we derive the principle of LEO satellite communication link clock bias elimination; then, we give the principle and process of the algorithm. Next, we model and analyze the error of the system. Subsequently, based on the unscented Kalman filter (UKF), we model the state vector and observation vector of our algorithm and give the state and observation equations. Finally, for different scenarios, we conduct qualitative and quantitative analysis through simulations, and the results show that, whether in an altimeter scenario or non-altimeter scenario, the performance indicators of our algorithm are significantly better than the inertial navigation system (INS), which can effectively overcome the divergence problem of INS; compared with the medium earth orbit (MEO) constellation, the navigation trajectory under the LEO constellation is closer to the real trajectory of the aircraft; and compared with the traditional algorithm, the accuracy of each item is improved by more than 95%. These results show that our algorithm not only significantly improves the position error, but also effectively suppresses the divergence of INS. The algorithm is more robust and can satisfy the requirements of cm-level real-time location services in challenging environments.

Rain Attenuation Models for Mobile Satellite Communication in Sudan

2020 ◽  
Author(s):  
Arafa Omer Norain Malik ◽  
Mohammad Kamrul Hasan ◽  
Rashid A. Saeed ◽  
Rania A. Mokhtar ◽  
Siti Norul Huda Sheikh Abdullah ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Rain Attenuation ◽  
Attenuation Models ◽  
Mobile Satellite ◽  
Mobile Satellite Communication

scholarly journals Communication architecture of an early warning system

2010 ◽  
Vol 10 (11) ◽  
pp. 2215-2228 ◽  
Author(s):  
M. Angermann ◽  
M. Guenther ◽  
K. Wendlandt
Keyword(s):  
Early Warning ◽  
Early Warning System ◽  
Satellite Communication ◽  
Warning System ◽  
Early Warning Systems ◽  
Lessons Learned ◽  
Warning Systems ◽  
Communication Architecture ◽  
Design And Implementation ◽  
Communication Links

Abstract. This article discusses aspects of communication architecture for early warning systems (EWS) in general and gives details of the specific communication architecture of an early warning system against tsunamis. While its sensors are the "eyes and ears" of a warning system and enable the system to sense physical effects, its communication links and terminals are its "nerves and mouth" which transport measurements and estimates within the system and eventually warnings towards the affected population. Designing the communication architecture of an EWS against tsunamis is particularly challenging. Its sensors are typically very heterogeneous and spread several thousand kilometers apart. They are often located in remote areas and belong to different organizations. Similarly, the geographic spread of the potentially affected population is wide. Moreover, a failure to deliver a warning has fatal consequences. Yet, the communication infrastructure is likely to be affected by the disaster itself. Based on an analysis of the criticality, vulnerability and availability of communication means, we describe the design and implementation of a communication system that employs both terrestrial and satellite communication links. We believe that many of the issues we encountered during our work in the GITEWS project (German Indonesian Tsunami Early Warning System, Rudloff et al., 2009) on the design and implementation communication architecture are also relevant for other types of warning systems. With this article, we intend to share our insights and lessons learned.

Validation of New ITU-R Rain Attenuation Prediction Model over Malaysia Equatorial Region

MAPAN ◽  
2018 ◽  
Vol 34 (1) ◽  
pp. 71-77 ◽  
Author(s):  
F. A. Semire ◽  
R. Mohd-Mokhtar ◽  
I. A. Akanbi
Keyword(s):  
Prediction Model ◽  
Rain Attenuation ◽  
Equatorial Region
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