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Responsiveness is a challenge for space systems to sustain competitive advantage over al-ternate non-spaceborne technologies.For a satellite in its operational orbit,in-orbit responsiveness is defined as the capability of the satellite to respond to a given demand in a timely manner.In this paper,it is shown that Average Wait Time(AWT) to pick up user demand from ground segment is the ap-propriate metric to evaluate the effect of ground segment location on in-orbit responsiveness of Low Earth Orbit(LEO) sunsynchronous satellites.This metric depends on pattern of ground segment access to satellite and distribution of user demands in time domain.A mathematical model is presented to determine pattern of ground segment access to satellite and concept of cumulative distribution function is used to simulate distribution of user demands for markets with different total demand scenarios.Monte Carlo simulations are employed to take account of uncertainty in distribution and total volume of user demands.Sampling error and standard deviation are used to ensure validity of AWT metric obtained from Monte Carlo simulations.Incorporation of the proposed metric in the ground segment site location process results in more responsive satellite systems which,in turn,lead to greater customer satisfaction levels and attractiveness of spaceborne systems for different applications.Finally,simula-tion results for a case study are presented.
Responsiveness is a challenge for space systems to sustain competitive advantage over al-ternate non-spaceborne technologies. For a satellite in its operational orbit, in-orbit responsiveness is defined as the capability of the satellite to respond to a given demand in a timely manner .In this paper, it is shown the Average Wait Time (AWT) to pick up user demand from ground segment is the ap-propriate metric to evaluate the effect of ground segment location on-orbit responsiveness of Low Earth Orbit (LEO) sunsynchronous satellites.This metric depends on pattern of ground segment access to satellite and distribution of user demands in time domain. A mathematical model is presented to determine pattern of ground segment access to satellite and concept of cumulative distribution function is used to simulate distribution of user demands for markets with different total demand scenarios. Monte Carlo simulations are employed to take account of uncertainty in distribution and total volume of user demands.Sampling error and standard deviation are used to ensure validity of AWT metric obtained from Monte Carlo simulations. Corporation of the proposed metric in the ground segment site location process results in more responsive satellite systems which, in turn, lead to greater customer satisfaction levels and attractiveness of spaceborne systems for different applications. Finally, simula- tion results for a case study are presented.