Prof. Francis X. Bostick, Jr.: 1st June 1932 - 20th October 2021

Francis X. Bostick
Francis X. Bostick

Carlos Torres-Verdin

Professor Francis X. Bostick, Jr. passed away peacefully on October 20, 2021. See his official obituary here.

He will be remembered affectionately by his many students and colleagues for being an excellent and passionate instructor and for his brilliant mind tackling challenging electromagnetic (EM) engineering problems, including those associated with subsurface exploration. Francis was original and creative in his research projects and in his way of thinking, looking always for simplicity and efficiency.

He had a peculiar and uncanny ability to solve problems with strong physical intuition and with abundant sense of practicality. He often invoked circuit analogies or approximations thereof to understand and approach every single scientific challenge that crossed his way, from satellite navigation and GPS, to wireless power delivery.

Even after retiring from the University of Texas at Austin, he could often be found learning about new EM sensors and systems, and never stopped programming algorithms to simulate EM wave propagation.

During his last few months alive, he was avidly revisiting the so-called magnetotelluric "tipper" method, developing new measurement acquisition and interpretation methods.

It was a great pleasure to hold conversations with him. He was unassuming, humble, and comfortable with himself, never voicing a bad comment about anyone and always discovering the positive side of everything.

Francis's family was his greatest pride and his wife, sons, daughter, and grandsons/daughters adored him.

We have lost a beautiful mind. His heart, soul, smile, and friendly Texas drawl will remain many years thence with those of us who had the great fortune to be guided and mentored by him.


Carlos Torres-Verdin, PhD, Professor, University of Texas at Austin.

Research Career

Professor Francis X. Bostick, Jr. received his B.S.E E. degree from UT Austin in May, 1955. That summer he entered the Graduate School of Electrical Engineering and started working with the Electrical Engineering Research Laboratory located at what is now UT's Pickle Research Campus. The research at that lab was focused on the effect of atmospheric conditions on the propagation of microwave signals. It was in the pre-satellite era and the main objective was to find ways to improve "beyond the horizon" radar surveillance. Dr. Bostick's role in the project was to collect meteorological data and correlate them with the fluctuations of microwave signals. This effort introduced him to the field of data recording and analysis that remained a significant part of his work throughout his academic career.

In the late 1950s, the Office of Naval Research contacted Francis's research group to explore whether they could develop equipment to sense, record, and analyze the small fluctuations that occur in the geomagnetic field. These fluctuations, called "micropulsations", are caused by gusts in the solar wind interacting with the outer reaches of the earth's steady magnetic field. The interaction gives rise to disturbances that propagate worldwide as hydromagnetic waves in the ionized upper atmosphere to ultimately appear as fluctuations of the magnetic field at the earth's surface. Although small in amplitude, such micropulsations originated noise that limited the capabilities of magnetic sensing methods being developed at the time. The first project was to build a 50-foot diameter induction coil to monitor the magnetic field on Grand Bahama Island, down range from Cape Canaveral. It was theorized that missiles launched from the Cape would produce a magnetic signature when entering the ionosphere. Measurements performed during the passage of a number of missiles failed to detect any features above the background noise. However, involvement in that project sparked Dr. Bostick's interest in geomagnetic phenomena and this area became a centerpiece of his research efforts for the rest of his career.

Shortly after the missile experiments, both the US and Russia began detonating nuclear devices at ionospheric levels in the atmosphere which produced large disturbances that, like natural micropulsations, propagated worldwide as hydromagnetic waves. Dr. Bostick became involved in both theoretical and experimental studies of how these waves propagated and could be detected by sensors at the earth's surface. As part of those studies Dr. Bostick's research group recorded and correlated micropulsation activity at sites in the US, Puerto Rico, Hawaii, and the Philippines. Although the research was successful, the eventual deployment of satellites proved to be a more direct method of monitoring surface and high-altitude nuclear detonations.

The presence of foreign submarines in US coastal waters was considered a threat to the security of the nation. Methods used to detect the intruders comprised sonar and magnetic detection devices. Once again, geomagnetic micropulsations represented the noise "floor" for magnetic detection. Dr. Bostick's research group studied ways of deploying multiple sensors to distinguish between micropulsations and the magnetic signatures of passing ships. This involved both theoretical and experimental efforts that included the measurement of magnetic signatures from ships passing through the Corpus Christi Ship Channel. The project concluded with remote detection of submarines operating at the Underwater Submarine Test Range at St. Croix Island.

When geomagnetic micropulsations contact the earth they induce electrical currents in the subsurface. These currents are called "telluric" currents. A method of measuring electrical properties of the earth by investigating the relationships between micropulsations and telluric currents was discovered by Louis Cagniard, a French scientist. He named this method "magnetotellurics", customarily referred to with the acronym MT. Beginning in the 1970s, much of Dr. Bostick's remaining career was spent using and expanding the capabilities of the MT method for exploring the inner earth's structure. This required the development of special electrodes to be placed in contact with the earth to measure electric potential differences caused by telluric currents. Also developed were both iron and ferrite core induction coils to sense the magnetotelluric signals over a six-decade frequency range that extended from 0.001 Hz to 1 kHz.

A number of field surveys were made with this MT equipment. The first was intended to investigate the structure of the earth's crust adjacent to the Llano Uplift in Central Texas. A second survey was done in cooperation with faculty at the University of Wisconsin at Madison. That survey was carried out to investigate the electrical substructure of the Wisconsin Arch. Several surveys were also conducted in cooperation with the U.S. Geological Survey in known geothermal areas of Yellowstone National Park, the Snake River Plain in Idaho, and the Big Island of Hawaii. The latter were done to verify the efficacy of the MT method for locating subsurface accumulations of magma. Magma is a good electrical conductor at elevated temperatures, hence presents an excellent target for MT exploration.

As originally described by Cagniard, the magnetotelluric method was restricted to estimating the electrical conductivity of earth layers with 1D soundings. More typically the earth is multi dimensional and a 1D sounding can be quite misleading as to the spatial complexity involved in the subsurface. Estimating the true distribution of electrical properties in three dimensions proved to be a difficult task and much effort was spent addressing the problems involved. Techniques were developed to estimate apparent directional properties of earth structures from magnetotelluric data although these often only indicated the presence of multi dimensionality rather than properly defining it. It became apparent that the only hope of obtaining better estimates of the subsurface would require the acquisition of much more survey data than was being done at the time.

In the late 1970s, Dr. Bostick received a contract from the Department of Energy (DOE) to design, develop and test a magnetotelluric surveying system to collect large amounts of data. The system recorded both magnetic and telluric field data throughout the required six-decade frequency range. All the sensors, both magnetic and telluric, were battery operated and placed along a survey line to form elements of an array. Sensor data were transmitted by telemetry links to a remote base unit where they were preprocessed and recorded. The preprocessing procedure used a unique method that Dr. Bostick developed for obtaining the spectral content of the data which operated in real time.

Formal methods of estimating the electrical properties of the earth's subsurface require iterative computer procedures used to match model results with field data. This is possible for producing estimates of one- and certain two-dimensional structures but general cases in three dimensions were beyond the capabilities of even the largest computers. As an alternative to formal methods Dr. Bostick developed a technique based on the properties of the geomagnetic and telluric fields to obtain approximate, although plausible, estimates of the earth's electrical substructure with more direct interpretation of preprocessed MT data. The preprocessing procedures involved synthesizing arrays of variable dimensions to probe selectively deeper structures and was called "EMAP" or Electromagnetic Array Profiling.

Following the completion of the DOE-funded MT data acquisition system and the development of the EMAP interpretation method, Dr. Bostick's research group completed three test surveys. These were funded by a consortium of geophysical and major oil companies. Results from these surveys were generally in agreement with the geology either known or projected for the survey areas.

From the late 1950s until the end of his active research career, Dr. Bostick also consulted for major oil well service companies in the field of borehole geophysics. This included the analysis of the capabilities of acoustic logging devices and participating in the design, testing and development of electric logging tools. Electric logging tools consisted of electrode arrays to focus the measurements on zones at various distances lateral of the borehole walls. Dr. Bostick also developed computer codes for modeling the responses of the electric logging systems to inhomogeneous media surrounding the borehole.


Teaching Career

Dr. Bostick did not include college-level teaching in his future career plans when he received his B.S. degree. The high tech era was just beginning and taking a job in the exciting and rapidly developing post WWII electronics industry was his goal. He did, however, recognize the need for advanced education prior to entering the industrial world and enrolled in graduate school. In 1963, when he was about to finish his Ph.D., Dr. Bostick was asked whether he would be willing to teach a course in the Electrical Engineering Department that needed an instructor. He thought it would be a one-time experience so he somewhat reluctantly agreed. That was the beginning of his teaching career at UT that became his occupation for the next 45 years.

Dr. Bostick has forgotten what the subject of that course was that he taught in 1963. Most probably it was the first course in electronics since he routinely taught courses in that area throughout his tenure as an instructor. In 1963, active devices in electronic circuits were transitioning from vacuum tubes to discrete transistors. He remembers how unpredictable the characteristics of the early semiconductor devices were.

Over the years, Dr. Bostick taught undergraduate courses in three areas. As mentioned above, one was Electronics. The two main courses in that area were EE338 and EE338K. At the time, these two courses were required for all students and typically had enrollments of between 40 and 50 students. In the last two years that he was actively teaching he also taught a course in electrical and electronic circuits for non-EE majors. This course usually had enrollments of over 40 students.

The second subject area in which Dr. Bostick routinely taught was electromagnetic field theory. The first course in that area was EE325. For many years, it was required of all students, which meant that the enrollments were almost always larger than 40 students. He occasionally taught the follow-on course EE325K. It was an elective course with enrollments between 15 and 20 students.

The third area was Probability and Statistics. The course was EE351K and it was required of all students. Enrollments were usually 40 to 50 students.

Over the years, Dr. Bostick taught three different courses at the graduate level. One of these was a graduate course in electrical geophysics which was the subject of his research efforts and those of the graduate students working under his supervision. Also related to his research efforts was a graduate course that he taught that dealt with the theory of both acoustic and electromagnetic waves propagating in material media. Both of these research-related courses had relatively small enrollments of around 10 students. A somewhat larger number of students, maybe 20 or so, would take the graduate course on Electromagnetics that he taught on occasion.

In addition to teaching courses, Dr. Bostick supervised a number of graduate students. Most of these were part of his research team and were supported through grant and contract funding. In total, he supervised nine Ph.D. students and thirty students who completed the M.S.E.E. degree.

Dr. Bostick enjoyed his teaching career and the opportunity to work with students both undergraduate and graduate. Despite his initial plans to go into industry after receiving his B.S.E.E. degree, now he cannot think of a profession that would have been more rewarding for him. Dr. Bostick is not remiss to thank his two mentors who were responsible for giving him guidance in both teaching and research throughout his career. They were Prof. Harold W. (Skeet) Smith and Prof. William C. (Dusty) Duesterhoeft. Dr. Bostick also thanks the many students with whom he interacted and who provided him with the intellectual environment that made his teaching career so special.

Testament to his superior teaching skills, Dr. Bostick was distinguished with the following highly coveted teaching awards at UT Austin: