GPS attitude determination under antenna array geometry deformation

Multi-antenna GPS attitude determination is considered as an alternative source of orientation for future satellites. Conventional attitude algorithms of this kind require antenna geometry to be fixed and known. However, in several situations this might be not the case. Present work aims to discern different situations that arise when GPS antenna array structure is not rigid. In most general case, arbitrary antenna displacements are not observable; therefore attitude can be resolved only within the ambiguity caused by displacements. Nevertheless, if antenna array geometry deformation is somehow restricted, there exist observable combinations. We also analyze if inertial angular rate sensors (gyroscopes) can help to discern between antenna structure deformation and attitude change. In this case it is essentially important if deformations are constant or how they vary over time.