Low-frequency radars (such as P-band and L-band radars) can "see farther and see more clearly" because of their longer wavelengths, lower attenuation, and reduced sensitivity to stealth coatings. In modern air defense systems, they are key to anti-stealth radars. They can penetrate 1-meter-thick camouflage netting and 3-meter-thick bushes to identify hidden tanks and radar stations, and are less likely to trigger enemy warning systems, demonstrating significant advantages in covert detection.
Radar frequency diagram
Basic Characteristics of P-Band Radar
P-band radar typically operates in the frequency range of 300MHz to 1GHz. This band is like a long-distance runner in the field of radio: it has higher resolution than low-frequency radar and stronger penetration than high-frequency radar. Its typical characteristics include:
Wavelength range: 30cm to 1m;
Atmospheric attenuation: Approximately 0.01dB/km attenuation in rain;
Common applications: Hydrological research, archaeology, and underground exploration.
Unique advantages in penetration ability
P-band radar can penetrate vegetation and shallow ground surfaces, mainly due to:
Medium penetration: It can penetrate several meters of dry sand;
Leaf penetration: It can penetrate up to 80% of the tree height in broad-leaved forests;
Interference resistance: It is only 1/5 as susceptible to atmospheric turbulence as the X-band.
Typical Applications of P-Band Radar
Numerous international test cases exist, such as:
A 2018 helicopter-borne test in the Moroccan desert (450/860 MHz) verified the performance and underground detection capabilities of the P-band;
In geological exploration in the Inner Mongolian grasslands of my country, P-band SAR penetrated a 3-meter-thick layer of dry clay, discovering an underground coal seam outcrop;
MetaSensing's MetaSAR-P airborne multi-channel SAR, operating in the P-band, also explicitly claims sand penetration capability.
The P-band airborne synthetic aperture radar system developed by Tianjing Yunhu features long operating range, high resolution, and low power consumption. This system has undergone multiple flight tests and can be flexibly mounted on various platforms such as UAVs and helicopters to achieve rapid, large-scale data acquisition. The structural design employs a quick-release architecture, allowing for rapid installation on the underside of UAVs without specialized tools, significantly improving the efficiency of field operations.
System installation diagram
P-band radar, with its powerful penetrating capabilities, offers significant advantages in information acquisition during archaeological explorations involving shallow burial sites, small scales, and inconspicuous differences in physical properties. This technology requires no excavation or contact with the artifact itself, aligning with the "minimum intervention principle" of cultural heritage protection, and is particularly suitable for the protective exploration of immovable artifacts and fragile sites.
It is worth mentioning that Tianjing Yunhu previously successfully completed a P-band airborne radar underground structure information acquisition project in Minqin, Gansu, obtaining relatively ideal imaging results. In actual operation, the system not only boasts fast data acquisition speed but also the ability to process and generate real-time data on-site, fully verifying its feasibility and effectiveness in real-world archaeological scenarios.
Test environment
The flight path is designed for unilateral flight, and data collection is performed using an automatic flight path mode. The flight altitude is 300m, the downward angle is 50 degrees, and the flight path is quadrilateral.
Route planning
P-band radar, acting as a "X-ray vision" for acquiring underground information, has enabled a shift from "passive protection" to "active exploration" in fields such as archaeological discoveries, architectural preservation, and cultural relic detection through non-destructive detection technology. It not only provides solid support for the scientific protection of cultural heritage but also opens new paths for understanding the spatial forms and evolution of human history and civilization. In the future, with the development of intelligent and integrated technologies, P-band radar will play a crucial role in even more application scenarios.
