Science and Engineering Apprenticeship

Apprentice poster award winners and Honorable Mentions

About the Program

The Science and Engineering Apprenticeship is a competitive program for graduating high school seniors. The apprenticeship exposes students to laboratory research and development and provides a hands-on preview of a career in science and engineering. The students participate in research projects in electrical, mechanical, and aerospace engineering; physics; mathematics; or computer science.
Each student is supervised by a research scientist or engineer and given a project they will complete during the apprenticeship. In addition to these projects, the students learn about the different types of research done at ARL:UT through presentations from ARL:UT staff, a tour of ARL:UT's Lake Travis Test Station, and a chance for the students to showcase their research through technical reports and poster presentations.
The apprenticeship began as a part of the Department of Defense Science and Engineering Apprenticeship Program for High School Students and encourages students to pursue careers in the science and engineering disciplines, particularly in areas related to the needs of the U.S. Department of Defense. ARL:UT accomplishes this goal by carefully assigning each student to a research project that can be completed during the summer. When the program started, in the summer of 1982, nine students from five local high schools participated. Now, over 561 students have taken part in the program, and most have gone on to major in science or engineering in colleges throughout the United States. Many participants return to ARL:UT in student and research positions and stay on to contribute for several years.

2017 Student Projects

The ability to accurately and consistently measure the distance and direction between two points is necessary for precision surveying applications. Differential processing (DP) and precise point positioning (PPP) are two techniques that use satellite signals from global navigation satellite systems (GNSS) to determine the vector between two GNSS receivers. DP refers to directly estimating the three-dimensional vector between two receivers, assuming that most of the error is shared by both receivers and will difference out. PPP refers to computing the absolute position of each receiver by modeling for known error sources and then computing the relative vector between the two absolute positions. While studies have shown that short-range DP produces millimeter-level precision and PPP produces centimeter-level precision, there has not been, to the author's knowledge, a detailed study that compares the relative performance of DP with that of PPP for varying baseline lengths. This study employs 85 baselines of varying magnitudes between International GNSS Service (IGS) stations around the world on January 1–10, 2016, and compares the performance of the Trimble Business Center (TBC) differential processor with Grape, a PPP tool. Assuming the published IGS station positions are “truth” values, TBC provides millimeter-level precision that asymptotically approaches Grape's constant centimeter- level precision. Because the precision of TBC outperforms Grape at baselines of hundreds of kilometers, it is suspected that TBC is employing many known error-source models within its differential processor. This study shows that modern differential processors that incorporate error models typically employed in PPP are the future of high-accuracy and -precision surveying tools across all baseline magnitudes.
Space and Geophysics Laboratory
A need has been demonstrated for an alternative to explosive sound sources used in underwater acoustic experiments. Prior experiments have shown that breaking a rupture disk over an evacuated chamber produces a broadband pulse that could potentially be used as an impulsive underwater sound source. This investigation explored the characteristics of these waveforms as a function of the dimensions of the evacuated chambers. Six different chambers were tested, with the dimensional variations as follows (diameter × length): 3 × 9, 4 × 8, 4 × 12, 4 × 16, 6 × 18, and 6 × 24 inches. These chambers had dimensional aspect ratios of 2, 3, or 4. An experiment was devised to repeatably induce the rupture of the disks at an arbitrary depth and to measure the resulting acoustic waveforms as water filled the evacuated chamber cavity. To ensure the disks were broken at a standard depth, a rip-cord-cracking mechanism was designed and employed. In this paper, the experimental results are analyzed to determine if trends exist between the chamber geometry and the acoustic output. The discussion is focused on the resultant acoustic time series, spectral energy, and source level of the events. Furthermore, analysis will explore the viability of utilizing the rupture disk as a repeatable acoustic sound source.
Environmental Sciences Laboratory
Electroencephalograms (EEGs) are measurements of brain activity that detect voltage fluctuations created when groups of neurons fire electrical impulses synchronously. Typically, EEGs are performed in a medical setting, using multiple components: electrodes, which transduce the voltage fluctuations; amplifiers, which strengthen the EEG signals; a computer control module, which interprets the data into a coherent format; and a display device. These signals are then categorized and analyzed in frequency bands. Typical bands of interest include delta waves (0.1–4 Hz), theta waves (4–8 Hz), alpha waves (8–12 Hz), beta waves (12–30 Hz), and gamma waves (below 30 Hz), each of which correspond to different functions in the brain. These experiments typically take 30–45 minutes and are conducted in places isolated from regular environmental stimuli. Recently, however, portable versions of the EEG have become available. These allow for continual monitoring of a person’s brain activity, which allows for the study of subjects in day-to-day activities. However, the ability to create or monitor stimuli, such as sounds, is not included with these headbands. Furthermore, the portable devices are considered consumer grade and are infrequently used for research due to lower sampling rates, inadequate external stimuli monitoring, and other complications of the real world. The objective of this project was to adapt an existing portable EEG data collection platform to be used for scientific data collection. The project was developed on a laptop, which enables real-time analysis of brain activity, along with the capability of providing synchronous audio stimuli to the subject.
Signal and Information Sciences Laboratory