Concept of an algorithm to determine the signal delay time for telepresence space applications

The vision of a space robot as an extended arm of the human operator on ground is a key component for on-orbit robotic service missions. This concept of telepresence requires a high-quality sensor feedback from the space environment to the operator including stereo video and force-feedback. For the force feedback channel the knowledge of the signal delay time during operation is an important factor to increase the immersiveness of the system. In case of radio contact to space segments which are not in GEO, the signal delay time varies according to the distance between the spacecraft and the ground station. This paper proposes a method for deriving the required signal delay from the Doppler frequency shift alone which is readily available from the receiver since the actual signal delay is an input value for the control loop in the haptic channel