## 1 Introduction
\begin{table}
\begin{tabular}{|l|l|l|l|l|} \hline
**L-BAND RADARS** & **Applications** & **Peak Power** & **Freq. Band** & **H**\({}^{*}\) \\
**Model** & & **[MW]** & **[MHz]** & \\ \hline
**Others** & & & \\ TM23 MA, AASR-804 & Airport Surveillance Radar & 0.5 & 1250–1370 & - \\ AVIA-C, ATCR-2T, 4T, 22, 44 & Air Route Surveillance Radar & 0.5–2 & 1250–1400 & - \\ TARS & & Tethered Aerostat Radar System & 1432–1435 & - \\ Guidance systems & Guided weapon system.Mil. & & 1427–1435 & - \\ \hline
**MOBILE AND NAVIGATION SATELLITE SERVICES**. & & & \\ \hline
**Service** & **Freq. band [MHz]** & **H**\({}^{*}\) & **Comments** \\ \hline MSS & 235–322 & 5 & \\ \hline MSS & 335.4–399.9 & 4 & \\ \hline non-GSO MSS (Iridium) & 1390–1400 & **-** & Up-links to control and track satellites. \\ \hline non-GSO MSS (Iridium) & 1427–1432 & **-** & Down-links to control and track satellites. \\ \hline GSO MSS (Asia Cellular System—ACeS) & 1525–1559 & **-** & Down-link service \\ \hline GSO MSS (INMARSAT) & 1535–1543.5 & **-** & Satellite-ship down-link. \\ \hline
**OTHER SATELLITE SERVICES** & & & \\ \hline Broadcast satellite service & 620–790 & 2 & \\ \hline Meteorological satellites & 460–470 & 3 & Space to Earth communications. \\ \hline Space Operations & 1427–1429 & **-** & Earth to space commands. Allowed in all \\  & & & regions except region 1. \\ \hline Space Operations & 1525–1535 & **-** & Telemetry. Allowed in all regions. \\  & & & Space to Earth communications. \\ \hline Earth Exploration Satellites & 1525–1535 & **-** & \\ \hline GPS Nuclear Burst Detection & 1378.55–1383.55 & **-** & Informs about nuclear detonations around the \\  & & & world. \\ \hline GPS Range Applications Joint Program & 1350–1400/ & **-** & Re-broadcasts real time positioning \\ Office Data link System & 1427–1435 & **-** & information of high velocity manned and \\  & & & unmanned airborne platforms during test and \\  & & & training operations. \\ \hline Unprotected radio-astronomy & 1350–1400 & **-** & ITU-R, RR 720 \\ \hline Fixed Service & 1432–1435 & **-** & Support of proficiency training using tactical \\  & & & radio relay systems at specific Army bases \\ \hline Mobile service & 1432–1435 & **-** & Air-to-ground telemetry and ground-to-air \\  & & & remotely commanded links to support various \\  & & & operational and testing programs mainly at \\  & & military electronic test ranges. \\ \hline
**LAND SERVICES** & **Freq. Band [MHz]** & **H**\({}^{*}\) & **Comments** \\ \hline TV broadcast & 470–790 & 2 & UHF TV transponders around the world. \\ \hline Military services & 138–144 & 10 & Some military services use this band to support \\  & & air-to-ground, air-to-air and air-ground-air \\  & & tactical communications; air traffic control \\  & & communications; LMR (Land Mobile Radio) \\  & & nets for sustaining base and installation \\  & & support; and for tactical training and test range \\  & & support. The Navy’s AN/URY-1/2/3 provides \\  & & data communication required to down-link \\  & & tracking and instrumentation data from and \\  & & aircraft or a ship. \\ \hline \end{tabular}
\end{table} 
Table 1: _Cont._Figure 5 shows the world radio-electric spectrum division in three regions [8]. The fact that Europe is one of the regions most affected by RFI, while Regions 2 and 3 (except China, and conflictive zones) are generally clean (Figure 6), seems to indicate that fixed and mobile services (assigned in this band too, but only in Region 1), may be more important than radio-localization services (assigned in  
Figure 4: Map of interference power level for correlation errors \(e_{\mu}=10^{-2}\) and \(10^{-4}\) for an L-band radar located at (0, 0) and a satellite moving at a given cross-track distance from the radar (red arrow). Figure 5: World division in three radio-electric spectrum regions [8]. all three Regions) [8,9]. Figure 6 shows also the important effect that law enforcement can have in the quality of the data over large areas.