Space-based radar system for geostationary debris detection and tracking at MEO
- Paper number
IAC-05-B6.1.03
- Author
Ms. Marta Martí-Marqués, Technical University of Valencia, Spain
- Year
2005
- Abstract
Since the first known satellite fragmentation occurred just four years after Sputnik 1 was successfully put into orbit around our planet, it is believed that a total of 173 satellites have broken up, making the scientific community aware of the potential risks that space debris poses. In order to decrease the threat of operational spacecraft colliding with non-functional objects and to assess current and future population of space debris, cost-effective measurement techniques and devices capable of supplying us with the data required to conduct collision avoidance manoeuvres should be developed.
Our research aims to design a space-based detection and tracking radar system, which would provide much more accurate measurements of debris size and orbital parameters from densely populated GEO (Geostationary Earth Orbit). The orbiting device should be placed at MEO (Medium Earth Orbit), so that it allows full tracking of the geostationary arc in order to search GEO for non-functional spacecraft as well as for debris fragments and thereby update the current database of catalogued on-orbit debris population.
The detection and tracking radar system operating at Ka-band would supply us with valuable information for the characterisation of the near-Earth debris environment and the validation of space debris models. A directive large antenna would be required to generate short wavelengths and achieve high frequencies, as well as to provide a narrow beamwidth (high gain) capable of searching for non-operational spacecraft and debris clouds. Recent advances on microstrip patch antennas nevertheless prove that the building of such high performance radar would be cost-effective using planar technology.
Debris data would be collected by means of an electronically steerable phased array antenna, which could have its beam electronically steered in angle by changing the phase of the current at each radiating element, so that the region of constructive interference could be swept from side to side and look for targets. Despite the fact that attenuation of electromagnetic signals when propagating through the atmosphere or in adverse weather conditions can seriously degrade radar performance at high microwave frequencies, our in situ radar system does not have to face this challenge as it is a space-based device. Now then, on-board signal and data processing should be conducted before transmission by radio link to an Earth-based receiving station.
As it is not technically feasible to provide accurate enough ground-based measurements of targets located 36,000 km above the Earth surface, a MEO space-based radar would be the perfect solution due to the potential decrease of the distance between the observer and the object. The database built up from ground-based optical and radar facilities by means of traditional measurement techniques would be definitely improved if we update it with the accurate data our space-based radar will acquire. Functional spacecraft could use this database for advance warning of collisions with debris in order to manoeuvre out of the collision path.
In the final analysis, we believe that the proposed orbiting radar system would make a significant contribution to achieve a better understanding of the threats posed by the debris environment so that its impact on future space missions is minimised. For this reason, international cooperation is needed to evolve both technically and economically feasible alternatives to debris threats so that future space activities develop in a debris-free orbital environment. In this paper our space-based radar system will be described in detail and its operating parameters will be calculated to prove the feasibility of this new proposal and demonstrate its effectiveness in preserving the orbital environment for future generations.
- Abstract document
- Manuscript document
IAC-05-B6.1.03.pdf (🔒 authorized access only).
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