Apoorva T Karra, The University of Texas at Austin; Moriba Jah, The University of Texas at Austin
Keywords: harmful interference, radio frequency, itu, satellite, compliance, accountability, transparency, space sustainability, space domain awareness, space jamming
Abstract:
As space is becoming increasingly affordable, it is becoming crowded daily at a rapid pace. The need to have appropriate policies that tie in the accountability and liability of one’s space footprints for a sustainable future has never been more critical. As more and more geopolitical conflicts arise, the need to look at the actions in space with a new lens has also been critical over the past few years. These actions translate into harmful interferences in different orbital regimes. Although they have existed since the beginning of the space age, they are increasingly evident due to easier accessibility to space resources. According to the International Telecommunication Union (ITU), a United Nations specialized agency manages and coordinates the allocation of radio frequencies and satellite orbits globally. One of the primary responsibilities is ensuring equitable spectrum access and preventing interference between different satellite networks. According to ITU, 329 reports of harmful interference during 2021-2022 alone coincided with geopolitical tensions between Russia and Ukraine and hence warned all 193 member countries [1]. The current research focuses on the compliance of satellite operators in the radiofrequency spectrum aspect of the Geostationary Orbital (GEO) regime.
One of the main issues that propelled current research is the lack of real-time public awareness of non-compliant behaviors by satellite operators and, hence, reduced accountability that is not conducive to future space sustainability. After slot and frequency allocation by the ITU, one of the assumptions is that satellite operators will comply with the same throughout the satellite’s life span. However, that has not always been the case, as demonstrated by Roberts and Linares’ research [2] regarding the operator’s compliance with the physical slot. Also, there is no publicly available history of an operator’s level of compliance over time or the cases of harmful interference no matter the intent. In addition to the above, in the case of non-compliance, the operators have to coordinate either among themselves or with ITU, which can be a few months long process with the possibility of inconclusive results. Moreover, the existing policies lack a credit-based system that incentivizes compliance and penalizes non-compliant behaviors. Hence, the current research aims to incorporate the computation of harmful interference in real time and develop a tool that provides real-time compliance notifications to the public.
One of the research gaps in Roberts and Linares’ work is that their work does not compute compliance in the allocated frequency aspect, which is the main focus of the current research. The methodology is as follows: this work first maps the satellites in orbit to the satellite network filings by the administration and physical longitude as the process laid out in the earlier work. With the help of two-line element data, the amount by which a satellite is off from its allocated slot in longitude is computed in degrees. Then, from the Bureau of Radiocommunication International Frequency Information Circular (BR IFIC) circulars published by the ITU, relevant the antenna characteristics of the satellite network such as transmitting antenna gain, pointing accuracy, maximum total peak envelope power are used to compute the Carrier-to-Interference (C/I) ratio threshold, which is compared to 15 decibels (dB) threshold, as per ITU Radio Regulations (RR), under which is considered to be harmful interference. One key component of this computation is the geocentric angular separation between two GEO satellites. This value is used to compute the off-axis antenna gain reduction, which will be used to compute the interference power from the adjacent satellite. Based on this interference power, the C/I value is computed. An approximate proof-of-concept computation involving a Russian and Ukrainian satellite separated by 1 degree in longitude at 48 degrees East in GEO showed the possibility of satellites experiencing harmful interference. The computed C/I using the above-mentioned method was approximately 13 decibels (dB) in the ITU interference threshold of 15 dB. The satellites are assumed to operate in Ku-band (12 GHz).
The method proposed here is used as a back-of-the-envelope calculation for conducting independent analyses of harmful interference in GEO using data published by the ITU. The author recommends that the ITU establish a credit-based compliance system to track satellite operators’ historical compliance behavior, which can influence future spectrum allocations. The authors would also like to apply this method to investigate past incidents and identify behavioral trends of non-compliance among satellite operators. Past satellite jamming events include Iran jamming French operator Eutelsat’s TV and radio channels in 2022 due to its dissatisfaction with the coverage of its domestic issues and international policies by foreign media outlets [3] and Russia’s interference with GPS signals and television channels in several European countries coinciding with its invasion of Ukraine in 2022 [4].
References:
Telecom Review (2022) ITU warns of harmful interference with radio navigation satellite service. Telecom Review. Available at: https://www.telecomreview.com/articles/reports-and-coverage/6329-itu-warns-of-harmful-interference-with-radio-navigation-satellite-service (Accessed: 3 March 2025).
Roberts, T.G. and Linares, R., 2024. A method for assessing satellite operators’ compliance with geosynchronous orbital assignments. Acta Astronautica, 221, pp.218-229.
Rainbow, J. (2022) Eutelsat says satellite jammers within Iran disrupt foreign channels. Available at: https://spacenews.com/eutelsat-says-satellite-jammers-within-iran-are-disrupting-foreign-channels/ (Accessed: 10 September 2024).
Antoniuk, D. (2024) UN urges Russia to ‘immediately’ cease interference in European satellites. The Record. Available at: https://therecord.media/un-russia-satellite-interference-europe (Accessed: 10 September 2024).
Date of Conference: September 16-19, 2025
Track: Space Domain Awareness