Distributed Space Platform for Lateral Sar Swath Revisit: Geometry and Control

Distributed Space Platform for Lateral Sar Swath Revisit: Geometry and Control

Abstract

A distributed space platform consisting of several satellites taking turns passing over the swath of a lateral SAR instrument is presented. This enables co-observation of the same points on Earth by SAR and optical/infrared means. The swath lies to the side of the main satellite groundtrack and this poses geometrical challenges as it is impossible to place a satellite that is always on the swath. Analytic tools to obtain the swath and target points are presented and used to obtain the orbits of the members of the platform. Target point coordinates and interval between co-observations are used as inputs to determine these orbits, and a method to match a polygon of points on Earth to platfom geometry in space is presented. The guidance and control problem is addressed by introducing the Virtual Chief concept, where an idealized trajectory for this Virtual Chief acts as a set point for the members of the platform, which implement autonomous orbit keeping by trying to track this reference trajectory. Control implications are discussed and results showing sample platform configurations are shown.

Publication
Distributed Space Platform for Lateral Sar Swath Revisit: Geometry and Control
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