Understanding Satellite System Based On Orbit - Direct2U

Direct2U is direct broadcast satellite TV service company. They specialises in providing digital satellite television and radio to households in Malaysia, Singapore, Thailand, Indonesia and Brunei. In order to achieve this, they use the satellite technology to broadcast the television and radio contents. As a network consultant, you have been recruited to prepare a report to help the company shareholders to better understand the broadcast satellite TV service.

In your proposal:

                                                                                     Table 1: Satellite System Based on Orbit

a) Discuss THREE satellite systems based on orbit that have been identified in Table 1. Your task is to provide a clear and succinct report on the characteristics of each of the satellite system and emphasize the strengths/ benefits of each.

b) Recommend a satellite systems based on orbit that should be used to serve the company’s purpose. Your recommendation must be supported by relevant examples and considering the most suitable solution to address the location’s geographical properties.     

Satellite System Based on Orbit

Dircect2U is a communication organization that provides broadcast satellite TV services to their customers. They also provide the digital type of TV and radio to consumers in Thailand, Brunei, Malaysia, Singapore and Indonesia. Generally, they use the satellite technique and methods for broadcasting the radio and television (Chancellor, Scott, & Sutton, 2014). The main objective of this report is to understand the fundamental concept of satellite system and discuss the various kinds of earth orbit with their strength and weakness. In the field of the communication system, the satellite plays an important role that relays and increases the radio telecommunication waves with the help of transponder. It produces a communication channel between the transmitter source and a receiver with various locations on the orbit of the earth. This report is divided into four parts such as Satellite System Based on Orbit, types of a satellite system, advantages and disadvantages of GEO, MEO, and LEO and recommendation.

The satellite system is a modern technology that provides the communication process between two or more users.it provides a platform where consumers can share their data or information from one location to another (Chen, Xing, Sun, Gao, Liu, Guo, & Lan 2018). There are many application of satellite communication, for example, television, radio, internet, military and telephone. It is observed that wireless networks use EM waves to carry the input signal and these signals required the line of sight communication between transmitter and receiver. The orbit which is selected for the satellite communication that depends upon the application and for the broadcast television the geostationary orbit is used. Moreover, the satellite system can be used for the navigation purpose and in GPS and the selection of satellite orbit completely depends on the function and applications. There are mainly three kinds of orbits are used during the broadcast the TV and radios such as geostationary earth orbit, medium earth orbit, and low earth orbit (Chen, Reeves, Cunningham, Redmon, & Henderson, 2016).

In the field of satellite communication with the orbit system, there are three main orbits are used that provide the line of sight communication between the source and receiver such as:

• Geostationary earth orbit
• Medium earth orbit
• Low earth orbit

A geostationary orbit is also called as geosynchronous equatorial orbit that is a circular orbit and it is generally used for the broadcast applications. The main advantage of this satellite system is that the satellite does not change their position during the day and antennas can be directed along with the satellite (Gao, Yao, Cui, & Lu, 2014). The Direct2U use this technology for the b broadcast TV and radios because it is a very advanced communication system that can improve the performance of network systems. It is identified that when the height of the satellite system increases then the time taken by waves to move from satellite to orbit also increases. At the height 35790-kilo meter it will take around 24 hours for the movement from satellite to orbit and the main concept of this process is that it can synchronize with the earth (Huang, Qiu, Hu, Han, & Ding, 2015).

GEO

Figure: GEO

(Source: Huang, Qiu, Hu, Han, & Ding, 2015)

In this kind of orbit system, the satellite rotates in the same direction of the earth and it takes total 24 hours to cover 35000 km distance. It rotates at the same speed of the earth and in the same direction due to which it maintains the position of orbit. In order to check the speed of the satellite, it is necessary to check the time of the rotation and the movement of the earth can be determined with the help of the sun mean position.

Strength of GEO

• It has the ability to cover all parts of the earth
• The antenna can be fixed permanently
• Provide an effective output
• Can be used for long distance communication
• Take very less time

Weakness of GEO

• Larger antennas and components are needed
• Very limited process
• Large transmission energy is needed
• Cannot be used for the small mobile systems
• To fix the satellite at GEO orbit is very complex and costly

The medium earth orbit is not popular rather than GEO because the range of orbit is between hundred and thousand. The main advantage of this process in that the size of the satellite is very high as compared to low earth orbit. It is investigated that the orbital periods of this system are from 2 to 12 hours and few of the SMO satellite is near to the circles due to which the EM waves move at a fixed speed (Lou, Liu, Shi, Yao, & Zheng, 2014). The lowest altitude of an elliptical satellite is very less rather than their apogee and the rotation speed of perigee is very high than the apogee. The speed of orbit is very high for the perigee as compare to the apogee and a satellite is also called an elongated orbit that crosses the sky in just several minutes when it is close to the perigee. The few MEO satellite system can produce the wireless communication between two or more peripheral devices because they are very near to the surface of the earth as compare to GEO satellite (Pratt, Raines, Fossa, & Temple, 2011).

Figure: MEO

(Source: Pratt, Raines, Fossa, & Temple, 2011)

In which the earth-based transmission with low power and modest size antenna can access the communication system because the orbits system of MEO is very large rather than the low earth orbit. The MEO system can operate from the 10,000 to 20,000-kilo meter from the surface of the earth and any satellite communication use the very large frequency range (1-50 GHz) to transmit and receive signals (Zhao, et al., 2013).

Strength of MEO

• It is developed at the large altitude rather than LEO
• Very less propagation issue
• Very cheap and easy
• Can be used for long distance communication
• High-frequency range as compare to the LEO (Weaver, & Boyd, 2017).

Weakness of MEO

• The receiver cannot receive proper output signals
• It is visible only for the 2 to 7 hours from the earth
• More expensive rather than LEO
• Numbers of satellites are required to cover the region continuously

Low earth orbit

Low earth orbit is defined as a satellite process which is used in the field of telecommunication to transfer data from one user to another. The orbit of this system is between the 400 and 1000 miles from the surface of the earth and generally, this kind of technique is used for data communication, for example, emails, paging and audio or video conferencing (Ryden, Hands, Underwood, & Rodgers, 2015). They move from one location to another at very high speed and they are not fixed in the space. The LEO based communication system provide telephonic and wireless services to the underdeveloped countries and territories. In which the data shared by the transmitter is handed off from one satellite system to another but the main drawback is low orbit. Due to which the transmission stations are not much power to transfer data over long distance and in this modern generation most of the communication organization use the LEO technology because it takes very less energy to place a satellite into orbit (Stephani, & Boyd, 2016). They required only low power amplifiers to increase the performance of the input signal.

MEO

Figure; LEO

(Source: Stephani, & Boyd, 2016)

Strengths of LEO

• It is very close to the surface of the earth by which it can provide the better output signal
• Very less propagation delay
• The prices of satellite components are very low
• Very good global coverage can be achieved

Weakness of LEO

• Cannot be used for long distance communication
• Frequency range is very low
• Large atmospheric effects
• The LEO is only visible for only 15 minutes from the individual sector of the earth
• Very less effective

It is recommended that the GEO and MEO both are used by many organizations for communication and generally GEO is used in TV and radio communication because it is a more effective process. The problem of interface and propagation delay can be avoided by adopting a digital communication system rather than analog. The Dircet2U digital satellite TV and radio system and they used only GEO orbit to increase the efficiency of the communication system (Wang, Shi, Jiang, & Voss, 2016). For example, NASA involves the geostationary earth orbit to transfer data or information for long distance and the frequency range of this system is very large by which they can transmit a large number of signals. The use of GEO and more accurate amplifiers are the best solutions to address the location geographical properties and in future the Direct2U can modify their communication system to reduce the losses and distortion.

Conclusion

This report is completely based on the satellite system based on the orbit and Direct2U is an organization that provides TV and radio services to their consumers. It is a very biggest company that provide communication services in various countries, for example, Malaysia, Thailand, Brunei, and Singapore. This report described the fundamental concept of GEO, MEO and LEO orbit system with their properties. In all three systems, GEO is an advanced communication technique that can be used for long distance communication and it has the capability to increase the performance of TV and radio system. There are many benefits and weaknesses of geostationary earth orbit and medium earth orbit which are described in this report. The Dircet2U organization can adopt the advanced satellite orbit to improve the efficiency of the television and radio system and with the help of this report, readers can gather their knowledge in the field of broadcast satellite TV.

References

Chancellor, J. C., Scott, G. B., & Sutton, J. P. (2014). Space radiation: the number one risk to astronaut health beyond low earth orbit. Life, 4(3), 491-510.

Chen, J., Xing, M., Sun, G. C., Gao, Y., Liu, W., Guo, L., & Lan, Y. (2018). Focusing on Medium-Earth-Orbit SAR Using an ASE-Velocity Model Based on MOCO Principle. IEEE Transactions on Geoscience and Remote Sensing, 56(7), 3963-3975.

Chen, Y., Reeves, G. D., Cunningham, G. S., Redmon, R. J., & Henderson, M. G. (2016). Forecasting and remote sensing outer belt relativistic electrons from low Earth orbit. Geophysical Research Letters, 43(3), 1031-1038.

Gao, Y., Yao, Z., Cui, X., & Lu, M. (2014). For some critical static applications of Global Navigation Satellite Systems (GNSS), such as monitoring station and reference station in the GNSS control segment, the multipath error shows regular fading characteristics related to satellite orbit type. However, for Geostationary Earth Orbit (GEO) satellites, observations under different systems show great diversity, the regularity of the multipath fading... IET Radar, Sonar & Navigation, 8(1), 65-70.

Huang, L., Qiu, X., Hu, D., Han, B., & Ding, C. (2015). Medium-Earth-Orbit SAR Focusing Using Range-Doppler Algorithm With Integrated Two-Step Azimuth Perturbation. IEEE Geosci. Remote Sensing Lett., 12(3), 626-630.

Lou, Y., Liu, Y., Shi, C., Yao, X., & Zheng, F. (2014). Precise orbit determination of BeiDou constellation based on BETS and MGEX network. Scientific reports, 4, 4692.

Pratt, S. R., Raines, R. A., Fossa, C. E., & Temple, M. A. (2011). An operational and performance overview of the IRIDIUM low earth orbit satellite system. IEEE Communications Surveys, 2(2), 2-10.

Ryden, K. A., Hands, A. D., Underwood, C. I., & Rodgers, D. J. (2015). Internal charging measurements in medium Earth orbit using the SURF sensor: 2005–2014. IEEE Transactions on Plasma Science, 43(9), 3014-3020.

Stephani, K. A., & Boyd, I. D. (2016). Spacecraft plume interactions with the magnetosphere plasma environment in geostationary Earth orbit. Journal of Geophysical Research: Space Physics, 121(2), 1402-1412.

Wang, M., Shi, W., Jiang, L., & Voss, K. (2016). NIR-and SWIR-based on-orbit vicarious calibrations for satellite ocean colour sensors. Optics Express, 24(18), 20437-20453.

Weaver, A. B., & Boyd, I. D. (2017). Unsteady Simulations of Rocket Plume Expansions in Geostationary Earth Orbit. Journal of Spacecraft and Rockets, 54(6), 1258-1266.

Zhao, Q., Guo, J., Li, M., Qu, L., Hu, Z., Shi, C., & Liu, J. (2013). Initial results of precise orbit and clock determination for a COMPASS navigation satellite system. Journal of Geodesy, 87(5), 475-486.