Aloft Sensing and NASA built a radar that detects small surface changes without GPS. Could this change how we monitor disasters and the Earth?
Aloft Sensing, in collaboration with NASA, has developed a compact radar system capable of capturing extremely sensitive surface data without GPS, designed for high-altitude, long-endurance (HALE) platforms. This breakthrough allows detection of movements as small as a millimeter, such as shifts before volcanic eruptions or changes in snowpack, offering early warnings for natural disasters. The system has applications in both scientific research and national security.
Weighing under 7 kilograms and consuming less than 300 watts, the HALE InSAR radar fits on lightweight platforms without sacrificing accuracy. It can measure vertical terrain changes with centimeter-level precision and detect surface deformation at the millimeter scale. Its flat, tablet-sized phased array antenna electronically steers the radar beam, removing the need for heavy gimbals and enabling quick side-to-side imaging, capturing two synthetic aperture radar (SAR) images nearly simultaneously.
Unlike traditional systems, HALE InSAR does not rely on GPS. It calculates its exact position using advanced onboard algorithms based on radar feedback, making it effective in remote or GPS-denied locations, from disaster zones to polar regions. This GPS-free navigation also opens the system to civil, defence, and space applications.
Early tests have proven its performance at high altitudes, with flights at 65,000 feet using airships and stratospheric balloons. Upcoming trials on fixed-wing HALE aircraft will refine its capabilities, and future deployment on small satellites could enable global monitoring with frequent revisits and minimal infrastructure.
Conventional radar systems using interferometric synthetic aperture radar (InSAR) can track surface deformation, but they are bulky, heavy, and power-intensive, making them unsuitable for long-endurance platforms. HALE InSAR addresses these limitations by combining NASA-funded innovations, including a software-defined transceiver and a lightweight electronically steered antenna developed through ESTO programs.
The compact radar system provides clear advantages for environmental monitoring, disaster prediction, and defence applications. With its evolving design and high performance, HALE InSAR could become a key technology for airborne, suborbital, and orbital Earth observation missions.
