Synthetic Aperture Radar (SAR), a sophisticated digital imaging system that utilizes microwaves to generate highly detailed images, is poised to revolutionize various fields. Its ability to capture images under any weather condition—day or night, in fog, rain, or cloudy weather—sets it apart from other imaging technologies. Additionally, SAR can be adapted for use on multiple platforms, including satellites, planes, and drones.
Farohaji Kurniawan, a researcher at the Aviation Technology Research Centre (PRTP) of the National Research and Innovation Agency (BRIN) in Indonesia, underscores SAR’s versatility and wide-ranging applications. “SAR can be utilized in military, agriculture, disaster management, maritime, and national security. It is currently being refined using ground vehicles for enhanced safety and performance,” he noted.
Indonesia’s Pioneering Efforts in SAR Technology
Indonesia’s Rumpin Radar and Aerosenses Lab (RURAL), led by Farohaji, is at the forefront of SAR technology research and development in the country. The lab aims to master SAR technology independently and establish a lasting legacy in radar and digital imaging. The RURAL team collaborates with various BRIN research organizations, such as the Telecommunications Research Centre and the Polymer Technology Research Centre, to advance SAR technology.
“We have partially tested several supporting components of the SAR system, including horn antennas, planar antennas, back-scattering calibration, and various RF components. We are also replacing commercial parts with our research components. This year, we tested these systems from building tops and plan to conduct flight tests using UAVs by late 2024 or early 2025,” Farohaji explained.
Future Directions and Applications
The upcoming UAV flight tests require meticulous preparation, including detailed route and location planning. The team’s future plans include developing smaller, lighter SAR systems for quadrotors, small UAVs, and ground-based SAR (GB-SAR) systems for infrastructure monitoring. “GB-SAR can detect cracks, shifts, or damages in buildings, roads, bridges, and dams. It can also be used for disaster mitigation by monitoring mountains, hills, or steep cliffs prone to landslides,” Farohaji added.
SAR technology addresses the limitations of Real Aperture Radar (RAR) and optical sensors, offering high-resolution imaging even in obstructed environments. Unlike passive satellites that struggle in adverse conditions, SAR can capture clear images regardless of cloud cover or dense vegetation.
Technical Insights and Challenges
Farohaji elaborated on SAR’s functionality, explaining that the technology synthesizes the antenna width on the azimuth side to produce high-resolution images, earning it the nickname “side-looking radar” because it captures images at a 30 to 60-degree angle from the vehicle’s normal trajectory. Despite its advantages, SAR technology faces challenges, such as producing black-and-white images and generating large data files. High research costs have also hindered the full mastery of SAR in Indonesia.
The operation of the SAR system heavily relies on the antenna system, which functions as the sensor. “The antenna in a SAR system is like a pair of eyes, capturing signals from objects. The design and capabilities of this antenna are tailored to the system’s needs, whether on L-Band, C-Band, or X-band. Currently, we have developed a pair of identical antennas functioning as both transmitter and receiver,” Farohaji explained.
Integration and Future Prospects
SAR’s ability to integrate with digital technology and IT/ICT infrastructures positions it as a transformative tool for data acquisition and analysis, enhancing digital imaging capabilities across various sectors. As research progresses, SAR technology promises to revolutionize how digital images are captured and interpreted, offering unprecedented clarity and reliability.
Looking ahead, the development and integration of SAR technology within digital infrastructures are poised to usher in a new era of advanced data analytics and image processing. The ongoing advancements in SAR technology will significantly impact fields such as environmental monitoring, urban planning, and disaster response, heralding a future where high-resolution imaging from space becomes a cornerstone of safety and efficiency in numerous applications.