Abstract
Large-scale non-geostationary orbit (NGSO) satellite communication systems (SCSs) are emerging to play an important role for future global wireless communication. However, downlink transmissions from these mega-constellation SCSs can cause disruptive radio frequency interference (RFI) to the radio astronomy systems (RASs) on the ground or in space. Therefore, the satellite-based RASs including low earth orbit (LEO)-based or medium earth orbit (MEO)-based RASs are further considered to lower the impact from SCSs on the higher orbit onto the ground RASs and the lower orbit RASs. In this paper, we first analyze and compare the impact of RFI on LEO satellite-based RAS and MEO satellite-based RAS. The RFI results show that for both systems, RFI from higher orbit SCSs can totally undermine the RAS continuum observation adjacent to the SCS downlink bands when using the emission mask defined by National Telecommunications and Information Administration (NTIA). To solve the observation issues for both systems, we find out the required SCS emission mask for each RAS so that both systems can avoid RFI. Secondly, this paper also investigates three typical radio astronomy metrics such as maximum baseline distance (MBD), the number of simultaneously observing telescopes, and the signal to interference plus noise power ratio (SINR) performance. Our evaluation results show that the satellite-based RASs have greater MBD, thus, better spatial resolution, than the ground-based RAS. Due to the greater antenna gain of the ground telescopes, the SINR performance of satellite-based RASs may have limitations comparatively. However, because of more RFI sources at ground RASs in reality, satellite-based RASs have better chances to avoid RFI impact and potential SINR advantages. Additionally, we also explore the advantages of NGSO satellite-based RAS from a communication side. Our analysis shows that the large-scale NGSO satellite-based RAS can offer more spectrum access to both SCS and RAS.
Highlights
non-geostationary orbit (NGSO) satellite systems have already been deployed for years for traditional telecommunications and broadcasting
To ensure an acceptable radio astronomical observation (RAO), we find the required emission masks for both radio astronomy systems (RASs) and show the advantages of medium earth orbit (MEO)-RAS over low earth orbit (LEO)-RAS
The results show that the maximum baseline distances of both NGSO-RASs have strength over ground RAS and MEORAS is much larger than the LEO-RAS, which could lead to better angular resolution for MEO-RAS over LEO-RAS
Summary
NGSO satellite systems have already been deployed for years for traditional telecommunications and broadcasting. The telescopes are mostly influenced by the RFI coming from higher or equal orbits to ground connection so that interference from ground service and lower orbit satellites can be largely ignored This kind of space-based RAS has wider range of observation bands compared to the ground RAS due to the atmospheric influence, which implies that space-based RASs have complementary capability for various observation tasks. Technical Contributions: Using the OneWeb NGSO satellite system [24], [25] and ABS (Asia Broadcast Satellite)3A GEO satellite system [26] as examples, we first analyze and compare the RFI performance onto the LEO-based RAS from MEO SCS and the MEO-based RAS from GEO SCS based on the emission mask requirement in the Manual of Regulations and Procedures for Federal Radio Frequency Management by NTIA [1].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
