While geosynchronous satellites can have any inclination, the key difference to geostationary orbit is the fact that they lie on the same plane as the equator. A method to precisely estimate the azimuth bias for the geostationary satellite is introduced and evaluated with orbit determination results. An attitude and orbit determination and control system for. Combined spacebased observations of geostationary satellites. This handbook 0 geostationary orbits is in principle an extension of the introduction to geostationary orbits that was printed as a special publica tion by the european space agency esa in 1983. Therefore, in order to improve the orbits of the spacecraft in question, and thus improve the geolocation solution, improvements in solar. Orbit determination of geostationary satellite during. Coarse initial orbit determination for a geo stationary satellite using singleepoch gps measurements article pdf available in sensors 154. No single gnss can solve the problem of geo satellites line of sight nonavailability, but multi gnss improves the navigation performance. Request pdf validation of geostationary satellite orbit determination using singlestation antenna tracking data a method to precisely estimate the azimuth bias for the geostationary satellite. According to the analysis results, the onboard receiver can track 68 gps satellites, and the minimum and maximum carrier to noise spectral. Clarke in an article entitled extraterrestrial relays for wireless world. Any orbit relative to the chief is described in terms of equinoctial orbit element di erences and a linear mapping is.
Request pdf tjs2 geostationary satellite orbit determination using onboard gps measurements this study analyzes the quality of onboard data of tracking signals from gps satellites on the far. The receiver at station j demodulates the signals and the time delay. Jun 15, 2015 a geostationary orbit also known as a geostationary earth orbit, geosynchronous equatorial orbit, or simply geo is a circular orbit located at an altitude of 35,786 kilometers 22,236 miles above the surface of earth with zero inclination to the equatorial plane. Geo synchronous as the name itself suggests, is an orbit which is synchronized with the earths rotation to its own axis. Geostationary orbit determination using satre request pdf. Doll goddard space flight center gsfc greenbelt, maryland, usa abstract. The characteristics of the transfer ellipse and the total. Then, two strategies of orbit determination during satellite maneuvers are discussed in details. A satellite in a geostationary orbit appears stationary, always at the same point in the sky, to ground observers. Interferometric orbit determination for geostationary satellites. The ekf is a suboptimal approximation of the kalman lter for nonlinear systems, which has been shown to converge asymptotically when the initial state of the system is in the linear region 8. Examples include heliocentric, lunacentric and ariocentric mars examples as well as geocentric. Orbit determination for geostationary satellites with the combination of transfer ranging and pseudorange data guo rui 1,2,3,4, hu xiaogong 2,4, liu li 1, wu xiaoli 1. Pdf a multiple gnssbased orbit determination algorithm for.
Orbit determination of korean geo satellite using single. The remainder of this paper is organized as follows. A practical algorithm is proposed for determining the orbit of a geostationary orbit geo satellite using singleepoch measurements. The gps experiment on the ao40 spacecraft was first activated for approximately six weeks starting in september, 200 1, and was reactivated on may 1 1,2002. A oneway time synchronization method via a geostationary communication satellite was used.
In the context of a ground interferometer system, such observation data are the interferometric. The inorbit control of a spacecraft requires knowledge of its position in space. The application of global positioning system gps technology to the geostationary earth orbit geo determination has been constrained by the poor satellite visibility and weak signal power. Orbit determination of korean geo satellite using single slr. Improvement of orbit determination for geostationary. The cband transfer ranging method developed by the national time service center ntsc has been widely used in the chinese area positioning system caps, with its advantages of separating satellite ranging from time synchronization and being unaffected by. A satellite in this orbit is known as a geostationary satellite, and has an. The geostationary orbit is a special case of the geosynchronous orbit, which is any orbit with a period equal to earths rotation period. Geostationary orbits fall in the same category as geosynchronous orbits, but its parked over the equator. Investigation on geo satellite orbit determination based on. In section 3, the general ekfbased orbit determination scheme is discussed. Orbit determination accuracy improvement for geostationary. Precise orbit determination of a maneuvered geo satellite using caps ranging data.
The immediate purpose was to provide the theoretical background and some practical advice for the orbit control of geostationary spacecraft by means of the software package pepsoc. Angular tracking for geostationary orbits sciencedirect. Us6515617b1 method and system for position determination. An attitude and orbit determination and control system for a small geostationary satellite by g. The results show the residual is of the order of 40 cm by using these strategies, and the position difference between dynamic orbit and kinematics. An object in such an orbit has an orbital period equal to the earths rotational period, one sidereal day, and so to. Geostationary orbit determination for time synchronization. An operational orbit determination od and prediction system for the geostationary communication, ocean, and meteorological satellite coms mission requires accurate satellite positioning. The synchronization of rotation and orbital period means that, for an observer on earths surface, an object in geosynchronous orbit. The motion of geo satellites relative to a ground tracking station is almost fixed, and regular orbit maneuvers are necessary to maintain the. The satellite appears motionless at a fixed position in the sky to ground observers.
Geostationary definition of geostationary by merriamwebster. A realtime od filter is needed to operate a geostationary orbit geo satellite instantly and properly. Orbit determination has a long history, beginning with the prehistoric discovery of the planets and subsequent attempts to predict their motions. Johannes kepler used tycho brahes careful observations of mars to deduce the elliptical shape of its orbit and its orientation in space, deriving his three laws of planetary motion in the process. Geostationary earth orbit geokorea multipurpose satellite kompsat2b gk2b is a korean geostationary earth orbit geo satellite that is scheduled to be launched in 2020 for meteorological and ocean monitoring. The issue analyzed in this paper is the singularity associated with the simultaneous estimation of the satellites position and azimuth bias using tracking data from a single ground station when it is located near the longitude of the ground control. The accuracy of orbit determination has been evaluated from orbit residuals, the difference of orbital overlap. The angle between local horizontal plane and the plane passing through earth station, satellite and center of earth is called as azimuth angle. A new geo combined precise orbit determination pod strategy is studied in this paper, which combines pseudorange data and cband transfer ranging data. Interferometric orbit determination for geostationary. Accurate orbit determination for geostationary spacecraft poses particular problems for the very same reason that these orbits are used, namely the geometry of the.
A special case of geosynchronous orbit is the geostationary orbit, which is a circular geosynchronous orbit at zero inclination that is, directly above the equator. A geostationary satellite is in a geostationary orbit, which can only be achieved at an altitude very close to 35,786 km 22,236 m and keeps the satellite fixed over one longitude at the equator. N9527768 accurate orbit determination strategies for the. In section 4, simulations of the proposed algorithm and ekf are performed to test the accuracy and the availability of the proposed algorithm. One chief spacecraft, controlled from the ground, is responsible for the orbit determination and control of the remaining vehicles. The orbit improvements could be used both to reprocess the initial small subaperture with better motion compensation and to extend even more the integration time providing higher quality observations.
After smoothing the angular measurements over a tracking interval with a duration of a few days one can improve the accuracy by a factor of 2 or 3, but further improvements are impossible with this tracking method. That means calculus, full newtonion physics and statistical approaches. Geostationary orbit determination using satre sciencedirect. Statistical orbit determination for geostationary and geosynchronous satellite orbits in beidou constellation. Evaluation of cband precise orbit determination of. Tjs2 geostationary satellite orbit determination using onboard gps measurements. Beidou navigation satellite system bds space constellation is composed of geostationary earth orbit geo, medium earth orbit meo and inclined. The accuracy of the results improves significantly if distance measurements andor angular observations from other stations with sufficiently long baselines. List of satellites in geosynchronous orbit wikipedia. Pdf orbit determination for geostationary satellites. There is a small difference between geosynchronous and geo stationary orbits. It transmitted the first television signal to cross the pacific ocean when it relayed the 1964 summer olympics from tokyo, japan to viewers in the united states 8. The synchronization of rotation and orbital period means that, for an observer on earths surface, an object in geosynchronous orbit returns to exactly the same position in the sky after a period.
The orbit determination of the geostationary orbit satellite sino1 has been conducted based on the method mentioned above. In this work, angular observations used in conjunction with the orbit determination tool kit hujsak et al. Orbit determination of geostationary satellite during maneuvers. Pdf precise orbit determination for geostationary satellites with. Tjs2 geostationary satellite orbit determination using. It is assumed that the status of both stations i and station j are the same. A geostationary orbit, also referred to as a geosynchronous equatorial orbit geo, is a circular geosynchronous orbit 35,786 kilometres 22,236 miles above earths equator and following the direction of earths rotation an object in such an orbit has an orbital period equal to the earths rotational period, one sidereal day, and so to ground observers it appears motionless, in a fixed. The present paper reports the simulation study of the statistical orbit determination algorithm developed for geostationary and geosynchronous orbits for beidou constellation. Pdf a new precise orbit determination pod strategy based on the combination of satellite laser ranging slr and cband transfer ranging.
An attitude and orbit determination and control system for a. A geosynchronous orbit sometimes abbreviated gso is an earthcentered orbit with an orbital period that matches earths rotation on its axis, 23 hours, 56 minutes, and 4 seconds one sidereal day. Real time numerical dynamic orbit determination of. As an increasing number of geostationary satellites fill a limited number of orbital slots, collocation of satellites leads to a risk of close approach or misidentification.
Statistical orbit determination for geostationary and. A large number of orbit determination implementations also use ekf techniques 5. Lee computer sciences corporation csc lanhamseabrook, maryland, usa c. The roles of geo satellites are to improve the regional users positioning accuracy and provide the continuous radio determination satellite service. Proposed satellite position determination systems and. Coarse initial orbit determination for a geostationary. In section 2, the details of the coarse initial orbit determination algorithm are explained. The cband transfer ranging method developed by the national time service center ntsc has been widely used in the chinese area positioning system caps, with its advantages of separating satellite ranging from time synchronization and being unaffected by weather. Object correlation and orbit determination for geostationary satellites using optical measurements. One of the main challenges in geosar processing is accurately determining the satellite orbit to obtain a precise phase history, in order to properly focus the retrieved data. A relative orbit control concept for collocated geostationary spacecraft is presented. Request pdf geostationary orbit determination using satre a new strategy of precise orbit determination pod for geo geostationary earth orbit satellite using satre satellite time and.
Geostationary satellite an overview sciencedirect topics. Data fusion joseph chan1, hideshi chazono2, taku izumiyama3 1intelsat corporation, 3400 international dr. Information engineering university, 2006 huang y, hu x g, huang c, et al. A real time analytical orbit determination method has been developed for precision national time synchronization. Given at least three observations of a solar system body, his method consists of two steps. Such a model has already been created and tested using data from the air force maui optical and. Future geosar missions are expected to provide higher resolution radar images featuring shorter revisit times by locating a radar payload onboard of a geostationary satellite. However, the uncertainty of orbit determination od using single station tracking data is so high in the operation of three satellites at the 128. Orbit determination is the estimation of orbits of objects such as moons, planets, and spacecraft. Jun 27, 2018 this study analyzes the quality of onboard data of tracking signals from gps satellites on the far side of the earth and determines the orbit of the geostationary satellite using code and carrier phase observations with 30h and 3day orbit arc length. Gauss determined an orbit with piazzis observations.
Improvement of orbit determination for geostationary satellites with vlbi tracking. The time signals of the atomic clock at station i modulated by some pn code are dispatched to the satellite and then transferred to the station j via the satellite. At an altitude of 35,786 km, a satellite will have a period of one sidereal day. This strategy overcomes the deficiency of cband transfer ranging caused by limited stations and tracking time available. Pdf improvement of orbit determination for geostationary. One major application is to allow tracking newly observed asteroids and verify that they have not been previously discovered. Pdf chinas compass satellite navigation system consists of five or more geostationary geo satellites. There are several hundred communication satellites and several meteorological satellites in such an orbit. Ramanathan2 1 space applications centre isro, ahmedabad 380015. Pdf periodical orbit maneuver makes a serious problem for navigation users to get correct geostationary geo orbit information in realtime.
Us6515617b1 us09200,3 us200398a us6515617b1 us 6515617 b1 us6515617 b1 us 6515617b1 us 200398 a us200398 a us 200398a us 6515617 b1 us6515617 b1 us 6515617b1 authority. The vas geostationary satellite sounder demonstrated the exciting new opportunities for realtime monitoring of atmospheric processes and for providing, on a timely basis, the vertical sounding data at the spatial resolution required for initializing mesoscale weather prediction models. Geostationary definition is being or having an equatorial orbit at an altitude of about 22,300 miles 35,900 kilometers requiring an angular velocity the same as that of the earth so that the position of a satellite in such an orbit is fixed with respect to the earth. The satellite is said to be in a geosynchronous orbit because its period matches the rotational period of the earth. Evaluation of cband precise orbit determination of geostationary earth orbit satellites based on the chinese area positioning system. Object correlation and orbit determination for geostationary. The data from 6 june 2005 to june 2005 has been used for orbit determination. Orbit determination methods ceres was recovered in 1802 by h.
A communication satellite was carried by the space shuttle into low earth orbit leo at an altitude of 322 km and is to be transferred to a geostationary orbit geo at 35, 860 km using a hohmann transfer. For geostationary spacecraft the position is required relative to earthcentred axis. Geosynchronous vs geostationary orbits gis geography. Demonstration of precise orbit determination of geo. Investigation on geo satellite orbit determination based. The basic methods were discovered in the 17th century and have been continuously refined. The trick is to locate over the equator, and choose the. This particular orbit is used for meteorological and communications satellites. Pdf a multiple gnssbased orbit determination algorithm.
A geostationary orbit, also referred to as a geosynchronous equatorial orbit geo, is a circular geosynchronous orbit 35,786 kilometres 22,236 miles above earths equator and following the direction of earths rotation. A differential method was also applied to mitigate errors. Pdf orbit determination of geostationary satellite during. A study of the precise orbit determination of geostationary satellites in chinese. For orbit determination the extend kalman filter is a wellknown technique, but it requires accurate orbit dynamics modelling. There are two main types of orbit determination od filters. Application to geomagnetic storm times, manuscript in preparation for journal of geophysical research, 2005, hereinafter referred to as chen et al. If you want to see the raw math, this is the book for you. Aug 24, 2011 chinas compass satellite navigation system consists of five or more geostationary geo satellites.
Geostationary earth orbit geo satellites play a significant role in the space segment of the chinese area navigation system. This book grinds out the mathematical process of orbit determination in a rigorous manner. Thopil thesis presented in partial fulfilment of the requirements for the degree of master of science in electronic engineering at the university of stellenbosch december 2006 supervisor. Precise orbit determination of bds meo satellites based on. The ability to detect maneuvers made by these satellites using optical observations can help to prevent these problems. Cband ranging data, to determine the geo satellites orbit. Satellites at lower altitudes must travel faster to stay in orbit, thus, they will have shorter periods. This one special quality makes it unique from geosynchronous orbits.
Two software suites were available for orbit determination and analysis. Chinas compass satellite navigation system consists of five or more geostationary geo satellites. A spacecraft in this orbit appears to an observer on earth to be stationary in the sky. The concept for such an orbit was proposed in 1945 by british author and scientist arthur c. Geostationary orbit solutions a number of communication and weather satellites are currently in orbit around the earth at such a height and in such a position as to always be over a single point on the surface. Validation of geostationary satellite orbit determination. Geostationary orbit determination using satre article in advances in space research 485. The issue analyzed in this paper is the singularity.
This study analyzes the quality of onboard data of tracking signals from gps satellites on the far side of the earth and determines the orbit of the geostationary satellite using code and carrier phase observations with 30h and 3day orbit arc length. Animation showing geosynchronous satellite orbiting the earth. Multisatellite determination of the relativistic electron. A method to precisely estimate the azimuth bias for the geostationary satellite is introduced and evaluated with orbitdetermination results. The trick is to locate over the equator, and choose the correct distance from earth to cause circular. A real time numerical orbit determination method has been developed for a precise domestic time synchronization service. Initial results from the gps receiver were presented in february, 2oo2. The large errors in the latter are the major obstacle for improving the determination accuracy in the geostationary orbit. Astrometric positioning and orbit determination of. Geostationary orbit, a circular orbit 35,785 km 22,236 miles above earths equator in which a satellites orbital period is equal to earths rotation period of 23 hours and 56 minutes. Spacebased tracking data was collected during tracking intervals where both neossat and sapphire had visibility on the geostationary objects enabling astrometric orbit determination and photometric object.
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