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:
The geostationary orbital (GEO) regime is becoming increasingly congested as access to space becomes more affordable. This acceleration in satellite deployments, combined with rising geopolitical tensions, underscores the urgent need for transparent mechanisms that promote accountability and reduce harmful interference (HI) in shared orbital environments. The International Telecommunication Union (ITU), which governs global radiofrequency spectrum and satellite orbit allocations, reported 329 instances of harmful interference between 2021–2022 alone—many coinciding with the Russia-Ukraine conflict [1].
Current ITU policies assume satellite operators will maintain compliance across a satellite’s lifetime, but this is not always the case. As highlighted in Roberts and Linares’ work [2], operators often deviate from their assigned slots, and no comprehensive public record of longitudinal compliance or interference events exists. Furthermore, the process for resolving non-compliance through ITU coordination can span months and yield inconclusive results. The absence of a credit-based system that tracks operator behavior and incentivizes adherence further complicates governance.
This research addresses these gaps by introducing a method to independently compute harmful interference using publicly available orbital and antenna data. Building on prior spatial-slot compliance work, we extend the analysis to include frequency allocation violations. We map satellite positions from two-line elements (TLEs) to satellite network filings and extract key antenna parameters—such as gain, beam accuracy, and power—from the ITU’s Radiocommunication Bureau (BR)’s International Frequency Information Circular (IFIC) circulars. The geocentric angular separation between satellites is used to estimate off-axis gain and resulting interference power, which informs the Carrier-to-Interference (C/I) ratio. If the C/I drops below the ITU threshold of 15 decibels (dB), the event is classified as harmful interference.
A proof-of-concept involving Russian and Ukrainian satellites separated by 1° longitude at 48°E yielded a C/I of 13 dB, indicating non-compliance. Simulated Ku-band operations at 12 GHz validate this approach. The method is designed as a lightweight, reproducible calculation to enable independent auditing of on-orbit behavior.
We recommend that the ITU establish a public-facing credit-based compliance system to log and track operator behavior over time. This framework could inform future spectrum allocations and improve accountability. Additionally, this method can be used to revisit past interference incidents—such as Iran’s jamming of Eutelsat in 2022 [3] and Russia’s disruption of European satellites [4]—and identify systemic behavioral trends among operators.
Date of Conference: September 16-19, 2025
Track: Space Domain Awareness