Detailed processing procedure was developed to solve three footprint problems including the maximum downrange,the maximum cross-range with respect to a certain downrange and the inner footprint.Logarithmic form of constraints in "r-V" profile were introduced to simplify the expression of the entry corridor.The reentry trajectory was divided into three phases:the initial descent phase,the boundary tracking phase and the final adjusting phase,in which the design of the final adjusting phase could satisfy the final altitude constraint.The known quasi-equilibrium glide condition (QEGC) was introduced to obtain the analytic guidance law.The maximum downrange was given by tracking the upper boundary of the entry corridor.The maximum cross-range with a certain downrange was solved by translating the boundary tracking phase trajectory to cover the space of the entry corridor.The inner footprint was generated by following the lower boundary.The simulation results suggested that the proposed method could generate the closed landing footprint efficiently,and it was possible to apply the method to engineering practice,such as performance evaluation of the reentry vehicle,the objective point selection,and the evaluation of reentry guidance methods.%针对覆盖区的三个子问题——最大纵程问题、固定纵程下最大横程问题和内边界问题,设计了求解方法.在“r-V”空间内引入约束的对数表达形式简化了再入走廊的表达,提出了将再入轨迹分为“初始下降段、边界跟踪段和终端调整段”三段设计的轨迹规划方法,通过终端调整段的设计满足了再入终点的高度要求.为了跟踪所规划轨迹,引入了准平衡滑翔条件获取解析制导律.沿走廊上边界飞行获得最大纵程点;通过平移“边界跟踪段”轨迹使其布满再入走廊,解决固定纵程下的最大横程问题,获得外边界;而沿走廊下边界飞行获得覆盖区内边界.仿真结果表明方法快速、可行,在再入飞行器性能评估、再入任务设计和再入制导律评估等环节中具有工程应用价值.
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