# Role of Radio Telescopes in Space Debris Monitoring: Current Insights and Future Directions
## 5 Conclusions and Future Directions
This approach can enhance the detection accuracy, expand coverage beyond the low Earth orbit, and enable real-time monitoring of hazardous space debris. On the other hand, some of the radio telescopes discussed in this paper, such as BIRALES, MeerKAT, MWA, and LOFAR, operate based on the Very Long Baseline Interferometry (VLBI) principle or similar interferometric techniques, which \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Configuration** & \begin{tabular}{c} **Sensors** \\ **Involved** \\ **(Tx/Rx)** \\ \end{tabular} & **Country** & **Configuration** & \begin{tabular}{c} **Operating** \\ **Frequency** \\ \end{tabular} & \begin{tabular}{c} **Waveform** \\ **Type** \\ \end{tabular} & \begin{tabular}{c} **Detection** \\ **Performance** \\ \end{tabular} & **References** \\ \hline TIRA with & & & & & & Targets \(\geq 1\) cm & \\ Effelsberg & TIRA (Tx), & & & & RCS detectable & \\ Radio & Effelsberg (Rx) & & & & & at 1000 km & \\ Telescope & & & & & & \\ \hline Goldstone & & & & & & Targets \(\geq 3\) mm & \\ orbital debris & (Rx) & & & & & RCS detectable & \\ radar & & & & & & at 1000 km & \\ \hline Arecibo & & & & & & & \\ Observatory & & & & & & & \\ \hline BIRALES & & & & & & & \\ Medicina (Rx) & & & & & & & \\ \hline BIRALET & & & & & & & \\ (Rx) & & & & & & & \\ \hline Italian & & & & & & & \\ Multibistatic & & & & & & \\ Radar\({}^{\dagger}\) & & & & & & \\ \hline TIRA (Tx), & & & & & & & \\ Long baseline & & & & & & & \\ \(\begin{tabular}{c} bistatic radar\({}^{\dagger}\) \\ \end{tabular} & & & & & & & \\ \hline \multirow{3}{*}{\begin{tabular}{c} MeerKAT\({}^{\dagger}\) \\ \end{tabular} } & & & & & & & \\ \cline{2-5}  & & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \hline \multirow{3}{*}{\
\begin{tabular}{c} MeerKAT\({}^{\dagger}\) \\ \end{tabular} } & & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Muurchison \\ Widefield Array \\ (MWA) \({}^{\dagger}\) \\ \end{tabular} } & & & & & & & & \\ \cline{1-1}  & & & & & & \\ \cline{1-1}  & & & & & & \\ \hline LOFAR & & & & & & \\ \cline{1-1}  & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Overview of the radio telescopes analyzed in this study, providing a comparative summary of the systems examined. are known to enhance spatial resolution and measurement accuracy. In addition, future research can expand the characterization of space objects using multistatic interferometric ISAR imaging, as very limited research has been conducted in this domain. A notable application of high-resolution radar imaging, utilizing similar principles, is the IoSiS experiment conducted by the German Space Agency, DLR, for imaging satellites and space debris in LEO [100; 101]. Moreover, the mathematical model proposed in the recent literature [102] for the 3D imaging of resident space objects based on the interferometric approach needs to be further validated using real-world multistatic receiver networks. Its independence from the sensor system geometry makes it a promising approach for improving space object tracking and identification. This direction is further supported by the PRIDE experiment discussed in Section 3.6, which applied interferometric techniques for deep-space tracking and may inspire similar methodologies for space debris imaging in high-altitude orbits. The comprehensive analysis in this manuscript reveals that space situational awareness efforts are primarily led by the USA and European countries, while relatively fewer experiments have been conducted in other parts of the world. Research institutions and space agencies in the Asia-Pacific region, such as ISRO and JAXA, have the potential to adopt innovative approaches and further advance this technology. It should be emphasized that one of the key reasons for the limited analysis reported so far is the lack of publicly available data, as some space agencies classify such work for security and strategic reasons.