Description
Priority 2 activities will only be initiated on the explicit request of at least one delegation.
The objective of this activity is to investigate low-cost solutions to monitor the pointing and reflector surface profile of reflector based antennas during in-orbit operation.
Targeted improvements: To reduce the cost of current active antenna pointing systems based on RF sensors by 50% and to improve the in-flight reliability of geometry-reconfigurable antenna reflectors and diagnose deployable reflectors, including large mesh reflectors.
Description:
There is a strong interest to monitor the pointing and shape of reflector surface of a spacecraft antenna while it is in-orbit.
Antenna tracking systems currently use ground based beacons, and RF sensors integrated into the communications antenna to compensate for the motion of the antenna relative to the spacecraft AOCS sensors. To establish the shape of a reflector, the spacecraft is normally scanned over an IOT station to measure the reflector pattern, which can then be back transformed to a shape. However due to measurement uncertainties this method achieves a very poor accuracy.
Measurement of the reflector shape is also potentially useful to diagnose the deployment in-orbit (and possibly ground) of large mesh reflector. This information could be of great value for space segment operators and insurance companies in case of anomalies, which may be correctable where beams can be reconfigured. These techniques may also be useful in case where a flexible membrane-based reflector surface needs to be reconfigured in-orbit to check the shape of the final reconfigured surface.
The activity aims at investigating low-cost and highly accurate solutions to measure the in-orbit reflector pointing and surface profile. Promising technologies such as RFID tags, fibre optic sensors, optical systems making use of fringe projections (Moire patterns), or using videogrammetry techniques shall be investigated. The activity will be performed in 2 phases:
- The first phase will performing a state-of-the-art survey and establishing the requirements for such a measurement system. A baseline and a backup solution shall be selected after a trade-off analysis conducted among the different solutions. A preliminary analysis shall be performed for both baseline and backup solutions.
- The second phase will consist in the detailed analysis of the baselined solution for the in-orbit measurement of the reflector. Critical elements of the measurement system shall then be breadboarded.