Formalization of the problem of operative target functioning of diverse spacecraft for remote Earth probing
The existence of a steady and rapidly growing demand for remote probing data (RPD) stimulates organizations operating the domestic spacecraft grouping (RPD) and ground infrastructure to seek the ways to improve the system's efficiency. Presently, the topical problem consists in the lack of multi-objective planning of intended use of aggregate information resource of diversified orbital grouping, insufficient level of automation, the lack of means for feasibility calculation of consumers’ applications, insufficient operative planning horizon, which does not allow rational employing of a spacecraft technical capabilities. The article considers the issues associated with formalization of up-to-date task of target grouping operations planning for various types of remote probing spacecraft and development of a set of interrelated mathematical models necessary for specialized software developing that allows create optimal control programs for surveying in a realistic situation at a given planning interval. An approach to the solution of the planning problem for a spacecraft group of the one type is proposed. The initial set of surveying objects is being divided into subsets according to the type of shooting equipment specified in the consumer's application, and by the geometric parameters of the survey areas. Models for changing the occupied volume of the on-board storing device and changing the orientation of the line of sight of the camera are presented in the form of discrete equations of state. The basic formulas necessary for determining the moments of possible shooting of point and area objects, determining the boundaries of possible radio communication intervals with ground receiving points of information, checking the conditions of shooting by illumination and the amount of clouds over the survey area are presented. A technique for calculating the area captured in a single survey of a specific spacecraft and the area captured by a spacecraft group in the planning interval is described. As a model of the plan, a pair of interrelated programs is considered: a time sequence of switching on and off the survey and radio transmitting equipment of the spacecraft of the group and a piecewise linear program for reorienting the line of sight of the camera. A criterion for the effectiveness of the plan is introduced in the form of a linear convolution of the normalized information efficiency and the relative costs of the onboard resource of a group of similar spacecraft. The solution of the task of planning the target functioning of a grouping of diverse types of spacecraft is reduced to the sequential solution of planning problems for groups of the same type of spacecraft that are part of the initial grouping.