High school senior builds radar from scratch
High school seniors mark their final year of primary schooling in a number of ways; some do senior projects, ranging from volunteering at soup kitchens and animal shelters, to organizing blood drives, to coaching youth sports. Some students run for class president or write a senior thesis. One thing most of them don't do is build a functioning radar unit.
McKayla Leary is a recent graduate of Berwick Academy and attended the Lincoln Laboratory Radar Introduction for Student Engineers (LLRISE) in summer 2018. The two-week program gives around 20 rising high school seniors the opportunity to work with Laboratory employees to build and test a small radar unit; the program is now in its eighth year.
Students at LLRISE often work in small groups on their devices. Leary recalled that her group included a student with significant previous experience in some of the areas on which the program focused and that the group tended to defer to that student when things got difficult. As a result, Leary left feeling that she still had more to learn about radar.
Leary decided to pursue her radar education further in the form of an Innovation Pursuit, a feature of her Maine school Berwick Academy. The yearlong student-led pursuits pair individual students in middle and high school with mentors to explore an area of personal interest, culminating in a 10-minute presentation in May to a panel of adjudicators. Darcy Coffta, the Director of Innovation at Berwick Academy, said that "Innovation Pursuits allow students to design and drive a project around something they truly care about. Students are invested in the subject matter, and research shows that when students have agency, choice, and ownership of their education, the learning is deeper and more meaningful." The program has been in place for 10 years now, and in the 2018–2019 school year almost 70 students completed Innovation Pursuits.
Leary's mentor was Eric Phelps, a Laboratory employee who regularly assists with the LLRISE program. "Having a mentor was so helpful. I think if I had tried to take this on on my own, I would have been running around like a chicken with its head cut off," Leary said. "It was nice to know I had someone to go to with my questions who either knew the answer or knew the quickest way to [find] the answer."
Phelps was also excited to work with Leary. Because she was taking calculus, they would be able to delve more deeply into the math behind how a radar functions than they had been able to during LLRISE. The two met over Skype every Wednesday night, often talking for hours at a time. They also used a shared whiteboard website called Aggie.io to collaborate on various specifics of the radar and equations behind why it works.
The first step in building her new radar was to collect materials. Leary was the recipient of a $4,000 grant through Berwick Academy to develop her Innovation Pursuit. She was also able to obtain a bill of materials from Lincoln Laboratory, but even with these advantages some problem solving was needed. Certain parts had been discontinued so she and Phelps were forced to find alternatives. Some parts needed to be 3D printed, but when Berwick Academy's 3D printers proved unequal to the task, she had to track down a friend of her father's who happened to have a 3D printer. She was also able to obtain some parts, such as antenna plates, from Lincoln Laboratory.
January through March was spent constructing the radar. Because radar imagery is generated by reflecting radio waves off objects and measuring the waves' return times and then translating those times into a graphical representation, Leary's system needed a mechanical component (to generate the waves and measure their returns) and a software component (to interpret the data collected). Leary was focused on the mechanical aspects of the radar: "It was only frustrating because I would do something and short-circuit it and have to take the whole thing apart," she said. She estimates that this happened three or four times before the radar was completed.
Phelps, meanwhile, turned his energy toward the code that the radar needed to run. LLRISE uses code written in Matlab, which can be costly for students or schools since Matlab is not a free coding language. Phelps rewrote the radar code in Python, which is free, in part so that Leary could run it on her radar unit and in part as an investment in expanding the LLRISE program to underfunded students and schools. "I was kind of taking this as an opportunity to force myself to actually do it," he said.
At the end of March, Leary visited Lincoln Laboratory to meet with Phelps and run tests on her radar that she couldn't run at home. They used an oscilloscope, an electronic test instrument that measures and displays varying signal voltages, to make sure the radar was functioning as it was intended to.
After the radar was fine-tuned and complete, Leary ran a series of tests on it, gathering data to present to the panel of adjudicators at the upcoming Innovation Celebration. The radar featured both Doppler (measuring direction and velocity) and range (measuring distance) capabilities. She tested the first by having family members drive their cars past the radar and the second by covering the corner of a box in tinfoil (to help it better reflect radio waves) and waving it back and forth while slowly approaching the radar. In both tests, the radar performed as expected, leaving Leary with a device she felt very proud to present.
Leary's radar was featured at the tenth annual Innovation Celebration, the culmination of the year's Innovation Pursuits. In addition to delivering her 10-minute presentation to a panel of judges, she gave a demonstration to all the attendees during the evening's opening remarks. After setting up her radar on the stage, she pulled a volunteer from the audience to walk toward and away from it holding the same foiled box corner she had used in her earlier tests. As her volunteer approached the radar, a strip of blue projected on the screen behind Leary slowly reddened at the left-hand end, indicating that the object the radar detected was growing closer. "I wanted to highlight McKayla’s work for a variety of reasons," Coffta explained. "First, her dedication to the discipline, then her commitment to the field of science and engineering, and finally her passion to share this with all around her. McKayla perfectly exemplifies confidence and knowledge…. I could not think of a better speaker."
Leary will attend the University of Maine Orono this fall as a student of their honors program and plans to study mechanical engineering. She's looking forward to using skills that she built working on her radar — from hard skills like soldering and 3D printing to soft skills like problem solving and perseverance — for research at the collegiate level. "I'm definitely looking forward to helping out with research when I get the opportunity to," she said. "This was my first glimpse into that."