AbstractSatellite systems provide the most efficient and possibly the only means of achieving two-way global communications with mobile systems (ships, aircraft, and vehicular traffic). To date, such systems have used only circular orbits, either GEO or LEO. Medium altitude elliptical constellations, on the other hand, can provide an efficient and affordable alternative to these architectures. Users also benefit from their very high average and minimum elevation angles, resulting in minimum signal attenuation. Cobra Teardrop is unique in that it employs time synchronized 8-h left- and right-leaning elliptical orbits giving mid-latitude observers the illusion of viewing a single satellite continuously orbiting almost directly overhead! In reality, observers see six different satellites per day, for 4h each (while in their active duty cycles). By design, Teardrop satellites are physically in very close proximity at the handover points. This favorable geometry can be utilized to achieve a seamless handover from one satellite to the other (not requiring any electronic buffering). Handover is accomplished at the precise instant that the total path lengths from the transmitting station through both satellites to the receiving station are exactly equal. In these improved Cobra Teardrop arrays, an order of magnitude increase in global communications capacity (equivalent GEO slots) can be realized over earlier Basic Cobra systems. For decades into the future, these new orbital systems could satisfy a widely expanding range of commercial, government, and military high data rate communication requirements. These would include, but not be limited to, satellite cellular, air traffic control, meteorological, and combat net radio systems. With these arrays, a much larger number of system operators could be supported, without mutual electronic interference, than would ever be possible with circular orbits.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Seamless Handovers in Cobra Teardrop Satellite Arrays


    Contributors:

    Published in:

    Acta Astronautica ; 61 , 1-6 ; 139-150


    Publication date :

    2007-01-01


    Size :

    12 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Seamless Handovers in Cobra Teardrop Satellite Arrays

    Draim, Capt. John E. / Cefola, Dr. Paul J. / Ernandes, Kenneth J. | AIAA | 2006


    Seamless Handovers in Cobra Teardrop Satellite Arrays

    Draim, John E. | Online Contents | 2007


    Seamless Handovers in Cobra Teardrop Satellite Arrays

    Draim, J. E. / Cefola, P. J. / Ernandes, K. J. et al. | British Library Conference Proceedings | 2007


    Cobra Teardrop Arrays for Mobile Users with Seamless Handovers

    Draim, John / Cefola, Paul / Ernandes, Kenneth | AIAA | 2006


    AIAA-2006-5439 Cobra Teardrop Arrays for Mobile Users with Seamless Handovers

    Draim, J. / Cefola, P. / Ernandes, K. et al. | British Library Conference Proceedings | 2006