$390K NASA Jet Propulsion Lab Award Will Create a Space-Traversing Subsurface Radar Device
Electrical Engineering Assistant Professor Yanghyo Kim is designing technology that could make new discoveries on distant planets
Before joining Stevens in 2020, Professor Yanghyo Kim worked with the Jet Propulsion Laboratory (JPL), a robotic spacecraft research center and building facility owned by the National Aeronautics and Space Administration (NASA). There, he designed various types of sensors to be included on machines meant to be sent into space.
“I worked with them for five years before I joined Stevens,” said Kim. “I was an intern for three years and a postdoc for about two years.”
Since joining Stevens as an associate professor in electrical engineering, Kim has maintained this professional connection, and recently received funding from NASA/JPL to pursue a continuation of his previous research: a sensor that can detect objects underground.
Improving on a classic technology
The official name for what Kim is creating is a complementary metal-oxide semiconductor (CMOS) digital ground-penetrating radar with hardware-embedded artificial intelligence (AI) for subsurface exploration.
CMOS refers to the chip that will serve as the “brain” of the machine. “[This is the] technology in your cell phone, laptop, any modern mobile electronic [device],” said Kim. This type of chip is a good choice for sensors in space because it is tolerant to high noise — disturbances in the signal that might come from other electronics or from energy in space — and uses very little power.
The ground-penetrating portion of the radar is important because it allows for the detection of subsurface objects, “like ice layers or any other geological features that you don’t see with your eyes because they’re buried,” explained Kim. However, “the raw radar instrument is not sensitive enough to have the best dynamic range.”
Radar is actually an acronym: Radio Detection and Ranging. The technology spans back over a century, based on discoveries made in the late 1800s. The system has two parts: a transmitter that sends a pulse, usually a high-frequency electromagnetic wave, and a receiver that catches that pulse bouncing back off of an object.
Depending on what the radar is pointing at, the signal will come back changed. Those modified signals can be analyzed to determine what the radar is pointing at. However, the parameters of the radar cannot be preset when one is not sure precisely what that signal will be capturing, as is the case for underground projects performed in space. For this reason, Kim is utilizing hardware-embedded AI that allows for the sensor to adjust its range based on the signals it is receiving. This vastly improves the information that the radar takes in.
The electromagnetic waves that radar use are particularly useful for detecting objects that have high electrical conductivity, because these materials reflect the signal waves strongly. This makes radar ideal for attempting to detect water, and this is what Kim has in mind with his device design.
Exploring other worlds
“For instance, our moon supposedly has some subsurface ice layers,” said Kim, which currently could only be discovered by drilling holes and attempting to physically find them. “That is a waste of resources — we don't want to make holes everywhere!”
Kim’s device allows for much easier detection. “It’s noninvasive technology — we can scan without mechanical or physical drilling. We propose this technology to be used on other planets, like Mars.”
Kim expects to finish the design and the verification within three years. “Design is two years,” said Kim, and “the last year is going to be dedicated to testing.”
“The radar basic function can be verified here at Stevens, in the lab, using basic lab equipment. But the actual detection and environmental testing will be done at JPL.”
As of right now, Kim doesn’t know if the device that he creates will be adopted in an actual mission. His device could be sent out to distant planets and moons, and “discover water or ice layers that have never been discovered before.” For Kim, it would be a “major accomplishment of my career if that happens.”
But even if his device doesn’t ever make it out of the atmosphere, Kim is honored to be participating in such a project. “It is exciting because it's directly related to scientific discovery that has never been done before.”