Radar dome with power line interference.

Are Power Lines Messing With Your Radar? Understanding Active Interference

Beau Callahan in Tech & Innovation December 2025 • 4 min read.

"A closer look at how AC UHV power lines can affect airborne radar systems and what measures can be taken to mitigate the interference."

In our increasingly interconnected world, the demand for advanced technologies such as UHF (Ultra High Frequency) radio stations is higher than ever. These stations, encompassing analog and digital TV broadcasting, as well as military aviation radars, rely on a clear and stable electromagnetic environment to function correctly. Maintaining this environment, however, presents significant challenges, particularly when these systems are located near substantial infrastructure like UHV (Ultra High Voltage) transmission lines.

UHV transmission lines, essential for transporting electricity over long distances, can inadvertently introduce electromagnetic interference. This interference can disrupt the performance of sensitive equipment, especially air-to-air intelligence radars. These radars are critical for detecting, monitoring, and identifying airborne targets, as well as determining their coordinates and motion parameters. Ensuring their accuracy and reliability is paramount for both security and operational efficiency.

This article delves into the active interference caused by AC UHV transmission lines, with a specific focus on the interference generated by line corona on airborne intelligence radars operating nearby. Understanding this interference is crucial for establishing effective protection measures and maintaining the integrity of radar systems.

Understanding Active Interference: How Power Lines Impact Radar

Radar dome with power line interference.

Air-to-air intelligence radars operate across a broad frequency spectrum, initially from 3MHz to 30MHz, and now extended to the millimeter band (30GHz to 300GHz). The specific radars examined in this study function in the 80MHz to 3000MHz range, divided into two sub-bands: 80MHz to 300MHz and 300MHz to 3000MHz. According to the guidelines defined in GB13618-1992, "Electromagnetic Environment Protection Requirements for Airborne Information Radar Stations," there are specific requirements for guard spacing to mitigate potential interference.

The electromagnetic environment protection criteria primarily address two main interference sources from high-voltage overhead transmission lines and substations:

Radio Interference: High-voltage lines and substations produce radio interference during operation.
Obstruction and Reflection: The physical presence of high-voltage lines and towers can obstruct radar signals, impacting the radar's reflector surface, deforming the radar lobe, and affecting overall detection performance. These structures can also cause signal shielding or attenuation, leading to missed targets or reduced detection range.

To ensure adequate protection, standards such as GB13618-92 and GJBZ20195-3 provide guidelines for calculating the necessary protection spacing for radar systems near overhead transmission lines. These calculations ensure that interference is minimized, and radar performance is maintained.

The Future of Radar Protection

In conclusion, this study shows that UHV transmission lines have little radio interference above 80MHz. The active interference protection distance for radars near UHV transmission lines can follow existing standards, with a protection distance of 1600m. Using 1000kV single-circuit lines requires a 2400m spacing. For radar positions significantly above transmission lines, a 2400m reflection surface is sufficient, with a 1600m active interference protection distance. Always consult with radar station management and negotiate for other resolutions if protection spacing is challenging.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1051/e3sconf/20186405003, Alternate LINK

Title: Analysis Of Active Interference On Radio Station From Ac Uhv Power

Subject: General Medicine

Journal: E3S Web of Conferences

Publisher: EDP Sciences

Authors: Jiangong Zhang, Zheyuan Gan, Jun Zhao, Ying Lu

Published: 2018-01-01

Everything You Need To Know

How do Ultra High Voltage (UHV) transmission lines affect airborne radar systems?

Ultra High Voltage (UHV) transmission lines can introduce electromagnetic interference that disrupts the performance of airborne radar systems. This interference is especially impactful on air-to-air intelligence radars, which are vital for detecting and monitoring airborne targets. The physical presence of UHV lines and towers can obstruct radar signals, impacting the reflector surface and deforming the radar lobe, which affects overall detection performance. Signal shielding or attenuation can lead to missed targets or reduced detection range. This interference can be active, caused by line corona, or passive, resulting from signal obstruction and reflection.

What frequency range do air-to-air intelligence radars operate within, and why is this significant?

Air-to-air intelligence radars operate across a broad frequency spectrum. They initially operated from 3MHz to 30MHz, but now extend to the millimeter band (30GHz to 300GHz). Specific radars examined in the study function in the 80MHz to 3000MHz range, divided into two sub-bands: 80MHz to 300MHz and 300MHz to 3000MHz. This is significant because the electromagnetic environment must be clear and stable for these radars to function correctly. The expansion of frequency ranges underscores the need for robust protection measures against interference, particularly from sources like Ultra High Voltage (UHV) transmission lines, to maintain accuracy and reliability.

What are the primary sources of electromagnetic interference from high-voltage overhead transmission lines and substations that affect airborne information radar stations?

The primary sources of electromagnetic interference are radio interference and physical obstruction/reflection. High-voltage lines and substations produce radio interference during operation, which can disrupt radar signals. Additionally, the physical presence of high-voltage lines and towers can obstruct radar signals, impacting the radar's reflector surface, deforming the radar lobe, and affecting overall detection performance. These structures can also cause signal shielding or attenuation, leading to missed targets or reduced detection range. Both active interference and passive obstruction need to be addressed to ensure radar systems function effectively.

According to studies, what is the active interference protection distance required for radars near Ultra High Voltage (UHV) transmission lines, and how does it vary based on the transmission line configuration?

The study indicates that Ultra High Voltage (UHV) transmission lines have little radio interference above 80MHz. The active interference protection distance for radars near Ultra High Voltage (UHV) transmission lines can follow existing standards, with a protection distance of 1600m. Using 1000kV single-circuit lines requires a 2400m spacing. For radar positions significantly above transmission lines, a 2400m reflection surface is sufficient, with a 1600m active interference protection distance. It's important to consult with radar station management and negotiate for other resolutions if protection spacing is challenging.

What standards provide guidelines for calculating the necessary protection spacing for radar systems near overhead transmission lines, and why are these calculations important?

Standards such as GB13618-92 and GJBZ20195-3 provide guidelines for calculating the necessary protection spacing for radar systems near overhead transmission lines. These calculations are essential to ensure that interference from high-voltage lines is minimized, and radar performance is maintained. The standards help in determining the appropriate distance to mitigate both radio interference and physical obstruction, ensuring the radar systems can accurately detect and monitor airborne targets without significant disruption. Adherence to these standards is critical for the operational reliability and security of radar systems operating near substantial infrastructure like Ultra High Voltage (UHV) transmission lines.