Determination of Coverage Oscillation for Inclined Communication Satellite

Abstract

The communication engineers need to evaluate footprint movement to deploy a ground station. Geostationary communication satellite's inclination angle causes the movement of a satellite footprint. The calculation of the inclination angle requires complex astronomical knowledge and mathematical calculations. On the other hand, a satellite communication engineer does not need a very accurate inclination angle value to design a ground station for required service availability. We propose a practical method called trigonometric curve fitting for the inclination to solve the problem. The past and the future value of inclination can be evaluated by using the curve-fitting method. It is a simplified practical method and does not need advanced orbital dynamics knowledge. The orbit geometry and evaluated inclination angle are used for estimation of a coverage area movement. A satellite communication engineer can evaluate coverage area oscillation quickly and design a better link for an inclined orbit satellite by using the proposed method. We have evaluated the inclination angle of the communication satellite Sat-1 with the proposed method. Sat-1 spot beam movements and wide beam coverage area movements are estimated to obtain EIRP and G/T fluctuation for link budget purposes. The proposed method provides the results that are consistent with the results of measurements and the results of satellite operators' professional tools.

Performance Assessment of a Turn Around Ranging in Communication Satellite Orbit Determination

“…x= cos cos (4) y= cos sin (5) z= sin (6) where, is the range of the satellite, : azimuth angle : elevation angle, x, y, z : coordinate of the range between station and the satellite Figure 2(a) presents azimuth and elevation measurement of a satellite, the left vertical axis shows elevation angle data, and the right vertical axis shows azimuth angle data; Figure 2(b) shows station to satellite range and station to station range via satellite measurement of a satellite, the left vertical axis provides station to satellite range in km, and the right vertical axis provides station to station via satellite range in km. The horizontal axis is the observation number from one to forty-eight.…”

“…The orbit of a satellite must be known precisely to perform the required maneuver efficiently and obey co-location rules if required. So, precise orbit determination is a critical factor in successfully keeping a satellite at the desired orbital location [3], [4].…”

A Conjoint Analysis of Propellant Budget and Maneuver Life for a Communication Satellite

“…The satellite operators perform north-south station-keeping (NSSK) and east-west station-keeping (EWSK) maneuvers regularly to compensate for the perturbation in orbit. Figure 3(a) shows annual inclination increment and necessary ΔVNSSK starting from 2020 for 30 years [8]. It is seen that the ΔV requirement varies with time.…”

“…The sensor's accuracy is a major contributor to propellant gauging and calculations. [8]. The satellite operators may provide special services and protect their orbital rights with few amounts of fuel in inclined geosynchronous orbit (IGSO) for many years.…”

Salınımlı yörünge haberleşme uydularında 2 eksen düzeltmeli kapsama alanı stabilizasyonu

“…Bir haberleşme uydusunun yörüngesi ile ekvator düzlemi arasındaki açı Şekil 1'de görüldüğü gibi eğim açısı olarak tanımlanmaktadır. Salınımlı yörüngede işletilmekte olan uydunun ekvator düzlemi ile olan açısı başlangıç zamanına bağlı olarak yıllık 0,756° ile 0,952° arasında artmakta ve doğal salınım olarak 15° ye kadar ulaşmaktadır[3]. Salınımlı yörüngede işletilen haberleşme uydusunun artan eğim açısı iki temel soruna sebep olmaktadır.…”