Ascending Node

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Tang Guo-jian - One of the best experts on this subject based on the ideXlab platform.

  • Orbit Design of Sun-Synchronous Satellite
    Aerospace Shanghai, 2020
    Co-Authors: Tang Guo-jian
    Abstract:

    The determination method of descending/Ascending Node, longitude of Ascending Node and frozen orbit parameters for sun-synchronous orbit satellite design was analyzed on the basis of six general orbital elements. The key points of the design under the restrained conditions, such as orbit Node period, regressive cycles, regressive period, repeat period and others, were also presented. At last, an example of design for sun-synchronous, frozen and return orbit in the orbit of some satellite which altitude was 750 to 800 km was given.

  • The Method of Medium-Low Altitude Satellite Control
    Aerospace Shanghai, 2020
    Co-Authors: Tang Guo-jian
    Abstract:

    The theory derivation for in-plane maneuver on semimajor axis, eccentricity and perigee argument and out-plane maneuver on orbit inclination was presented in this paper. The simulation of inertial orbit capture, orbit maintenance and trim maneuver of inclination by the theory deduced was also done. The results showed that the in-plane orbit maneuver with high accuracy could be realized by semimajor axis, eccentricity and perigee argument change simultaneously. Moreover, out-plane inclination maneuver should be completed at perigee or apogee to influence right ascension of Ascending Node the least.

Xiaoqian Chen - One of the best experts on this subject based on the ideXlab platform.

  • WMNC - Traffic Prediction Based on Surrogate Model in Satellite Constellation Networks
    2019 12th IFIP Wireless and Mobile Networking Conference (WMNC), 2019
    Co-Authors: Quan Chen, Yi Zhang, Lei Yang, Yong Zhao, Xiaoqian Chen
    Abstract:

    The traffic within the satellite coverage region varies greatly with the satellite movement. Traffic prediction in the satellite constellation networks is beneficial and necessary. The satellite coverage traffic model is formulated and the traffic prediction model is proposed with two variables: the geographic longitude of Ascending Node and the time from passing Ascending Node. In any period, all satellites in the constellation can be described by the model with these two variables. A surrogate model based prediction method is adopted to solve the traffic prediction problem with time-independent ground traffic distribution. The simulation results show that the traffic variation is of multiple peaks and the predicted results achieve a good match with the real traffic variation.

  • Traffic Prediction Based on Surrogate Model in Satellite Constellation Networks
    2019 12th IFIP Wireless and Mobile Networking Conference (WMNC), 2019
    Co-Authors: Quan Chen, Yi Zhang, Lei Yang, Yong Zhao, Xiaoqian Chen
    Abstract:

    The traffic within the satellite coverage region varies greatly with the satellite movement. Traffic prediction in the satellite constellation networks is beneficial and necessary. The satellite coverage traffic model is formulated and the traffic prediction model is proposed with two variables: the geographic longitude of Ascending Node and the time from passing Ascending Node. In any period, all satellites in the constellation can be described by the model with these two variables. A surrogate model based prediction method is adopted to solve the traffic prediction problem with time-independent ground traffic distribution. The simulation results show that the traffic variation is of multiple peaks and the predicted results achieve a good match with the real traffic variation.

Kyle T Alfriend - One of the best experts on this subject based on the ideXlab platform.

  • J_2 Invariant Relative Orbits for Spacecraft Formations
    Celestial Mechanics and Dynamical Astronomy, 2001
    Co-Authors: Hanspeter Schaub, Kyle T Alfriend
    Abstract:

    An analytic method is presented to establish J _2 invariant relative orbits. Working with mean orbit elements, the secular drift of the longitude of the Ascending Node and the sum of the argument of perigee and mean anomaly are set equal between two neighboring orbits. By having both orbits drift at equal angular rates on the average, they will not separate over time due to the J _2 influence. Two first order conditions are established between the differences in momenta elements (semi-major axis, eccentricity and inclination angle) that guarantee that the drift rates of two neighboring orbits are equal on the average. Differences in the longitude of the Ascending Node, argument of perigee and initial mean anomaly can be set at will, as long as they are setup in mean element space. For near polar orbits, enforcing both momenta element constraints may result in impractically large relative orbits. It this case it is shown that dropping the equal Ascending Node rate requirement still avoids considerable relative orbit drift and provides substantial fuel savings.

  • j2 invariant relative orbits for spacecraft formations
    Celestial Mechanics and Dynamical Astronomy, 2001
    Co-Authors: Hanspeter Schaub, Kyle T Alfriend
    Abstract:

    An analytic method is presented to establish J2 invariant relative orbits. Working with mean orbit elements, the secular drift of the longitude of the Ascending Node and the sum of the argument of perigee and mean anomaly are set equal between two neighboring orbits. By having both orbits drift at equal angular rates on the average, they will not separate over time due to the J2 influence. Two first order conditions are established between the differences in momenta elements (semi-major axis, eccentricity and inclination angle) that guarantee that the drift rates of two neighboring orbits are equal on the average. Differences in the longitude of the Ascending Node, argument of perigee and initial mean anomaly can be set at will, as long as they are setup in mean element space. For near polar orbits, enforcing both momenta element constraints may result in impractically large relative orbits. It this case it is shown that dropping the equal Ascending Node rate requirement still avoids considerable relative orbit drift and provides substantial fuel savings.

  • J2invariant relative orbits for spacecraft formations
    Celestial Mechanics and Dynamical Astronomy, 2001
    Co-Authors: Hanspeter Schaub, Kyle T Alfriend
    Abstract:

    An analytic method is presented to establish J2 invariant relative orbits. Working with mean orbit elements, the secular drift of the longitude of the Ascending Node and the sum of the argument of perigee and mean anomaly are set equal between two neighboring orbits. By having both orbits drift at equal angular rates on the average, they will not separate over time due to the J2 influence. Two first order conditions are established between the differences in momenta elements (semi-major axis, eccentricity and inclination angle) that guarantee that the drift rates of two neighboring orbits are equal on the average. Differences in the longitude of the Ascending Node, argument of perigee and initial mean anomaly can be set at will, as long as they are setup in mean element space. For near polar orbits, enforcing both momenta element constraints may result in impractically large relative orbits. It this case it is shown that dropping the equal Ascending Node rate requirement still avoids considerable relative orbit drift and provides substantial fuel savings.

M. H. A. Youssef - One of the best experts on this subject based on the ideXlab platform.

  • Solar Radiation Pressure and Gravitational Waves Effects on Sun-Synchronous Orbits
    wjm, 2018
    Co-Authors: M. H. A. Youssef
    Abstract:

    For certain values of semi-major axis and eccentricity, orbit plane precession caused by Earth oblate is synchronous with the mean orbital motion of the apparent Sun (a sun-synchronism). Many forces cause slow changes in the inclination and Ascending Node of sun-synchronous orbits. In this work, we investigate the analytical perturbations due to the direct solar radiation pressure and gravitational waves effects. A full analytical solution is obtained using technique of canonical Lie-transformation up to the order three in (the oblateness of the Earth). The solar radiation pressure and gravitational waves perturbations cause second order effects on all the elements of the elliptic orbit (the eccentricity, inclination, Ascending Node, argument of perigee, and semi-major axis) consequently these perturbations will cause disturbance in the sun-synchronism. Also we found that the perturbation or the behavior of gravitational waves almost the same as the perturbation or the behavior of solar radiation pressure and their coupling will incorporate the sun-synchronism through the secular rate of the Ascending Node precession.

A. T. Jasim - One of the best experts on this subject based on the ideXlab platform.

  • On the long-period evolution of the sun-synchronous orbits
    Solar System Research, 2016
    Co-Authors: E. D. Kuznetsov, A. T. Jasim
    Abstract:

    The dynamic evolution of sun-synchronous orbits at a time interval of 20 years is considered. The numerical motion simulation has been carried out using the Celestial Mechanics software package developed at the Institute of Astronomy of the University of Bern. The dependence of the dynamic evolution on the initial value of the Ascending Node longitude is examined for two families of sun-synchronous orbits with altitudes of 751 and 1191 km. Variations of the semimajor axis and orbit inclination are obtained depending on the initial value of the Ascending Node longitude. Recommendations on the selection of orbits, in which spent sun-synchronous satellites can be moved, are formulated. Minimal changes of elements over a time interval of 20 years have been observed for orbits in which at the initial time the angle between the orbit Ascending Node and the direction of the Sun measured along the equator have been close to 90° or 270°. In this case, the semimajor axis of the orbit is not experiencing secular perturbations arising from the satellite’s passage through the Earth’s shadow.