Oral-History:Merrill Skolnik

About Merrill Skolnik

Merrill Skolnik

Merrill Skolnik began his engineering studies at Johns Hopkins late in World War II and worked in the Johns Hopkins Radiation Lab on proximity fuses and electronic warfare countermeasures. He joined MIT’s Lincoln Lab in 1955, working on radar. At the same time he taught a course on radar at Northeastern University, the basis for his 1962 book The Instruction of Radar Systems. After his departure from Lincoln Lab in 1959, Skolnik's employment with Electronic Communications Inc. (ECI) and with the Institute for Defense Analysis (IDA) provided him experience with communications systems for spacecraft, antennas, phase arrays, penetrating ballistic missile defenses, and countermeasures.

In 1965 Skolnik became Superintendent of the Radar Division of the Naval Research Laboratory, where he stayed until his retirement in 1996. Research at the NRL during Skolnik’s tenure included over-the-horizon (OTH) radar, space-based radar, Relocatable Over-the-Horizon (ROTH) radar, Inverse Synthetic Aperture Radar (adapting earlier periscope detection radar), Identification Friend or Foe (IFF) work, and ocean waves’ radar echo. In this interview, Skolnik explains that Airborne Warning and Control System (AWACS) technology originated as OTH radar for surveillance of the USSR, was adapted for strategic defense, and ultimately served as a tactical tool. Describing military approaches to research and development, Skolnik compares the influence of the Naval Research Laboratory with other service research labs. Skolnik compares the approaches of the U.S. and the Soviet Union to radar research during the Cold War.

Assessing the evolution of radar research, Skolnik attributes the decline of radar funding in the 1990s to the retirement of WWII and post-WWII scientists, as well as to maturation of radar technology. Skolnik hails doppler weather radar as an unsung, recent accomplishment. He also identifies international achievements in radar research.

In addition to discussion of research and development, Skolnik describes his teaching and professional activities. Beginning in 1970, he taught a graduate course on radar at Johns Hopkins. Skolnik joined the AIEE in 1944 during his first year of undergraduate studies, transferring his membership to the IRE as a graduate student around 1947. He was on the Proceedings of the IEEE editorial board and edited the publication for four years in late 1980s. He describes the role of professional societies, including the IEEE Aerospace and Electronic Systems Society, in fostering communication among laboratories. Skolnik describes the IEEE AES Radar Systems Panel and Dave Barton’s influence on its growth.

About the Interview

MERRILL SKOLNIK: An Interview Conducted by Michael Geselowitz, IEEE History Center, 22 February 2000

Interview #389 for the IEEE History Center, The Institute of Electrical and Electronics Engineering, Inc.

Copyright Statement

This manuscript is being made available for research purposes only. All literary rights in the manuscript, including the right to publish, are reserved to the IEEE History Center excepting that Mr. Skolnik's responses were provided as part of his official duties as an employee of the U.S. Federal Government, and are therefore not subject to copyright. Otherwise,no part of the manuscript may be quoted for publication without the written permission of the Director of IEEE History Center.

Request for permission to quote for publication should be addressed to the IEEE History Center Oral History Program, IEEE History Center at Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030 USA. It should include identification of the specific passages to be quoted, anticipated use of the passages, and identification of the user.

It is recommended that this oral history be cited as follows:

Merrill Skolnik, an oral history conducted in 2000 by Michael Geselowitz, IEEE History Center, Hoboken, NJ, USA.

Interview

INTERVIEW: Merrill Skolnik

INTERVIEWER: Michael Geselowitz

DATE: 22 February 2000

PLACE: Washington, D.C.

Education, Johns Hopkins Radiation Lab

Geselowitz:

This is the interview with Merrill Skolnik for the AS Project. Merrill, if you could tell me a little bit about your life and training—how you got involved in the things you got involved in.

Skolnik:

I graduated from the Johns Hopkins University School of Engineering in 1947 with a Bachelor’s degree and went on to receive the Master’s and Doctor of Engineering degree, all in electrical engineering. At that time the emphasis at Hopkins was on the power aspects of electrical engineering so when I received the doctor’s degree I had little knowledge of microwaves or electronics which were the “new” fields just after World War II. I made up for this deficiency even before receiving the doctorate by working at a Hopkins laboratory doing classified work for the Navy and the Air Force.

Geselowitz:

Was that the Applied Physics Lab?

Skolnik:

No, it was a laboratory in Baltimore known as the Johns Hopkins Radiation Laboratory (a popular name at that time for a university laboratory). It was not part of the Applied Physics Laboratory, even though - just like APL - it worked under Navy sponsorship on new concepts for proximity fuzes for air defense. For the Air Force it was involved in R&D in the then new area of electronic countermeasures. Gradually I began to learn about the real world of electronic engineering.

Lincoln Lab, MIT; radar research and teaching

Skolnik:

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When I went to work at MIT Lincoln Laboratory in 1955 I had the choice of joining a computer group or a radar group. I chose the radar group, but I have always wondered what my career would have been like if I had joined the computer group instead. At Lincoln Lab I was part of the team that designed the first and only US operational bistatic radar, which was installed in the DEW (Distant Early Warning) line for detection of Soviet bombers that might attempt to penetrate the northern part of North America. Later, I was part of the team that conceived the Ballistic Missile Early Warning System (BMEWS) and was the author of the report that described the radars that were later installed at three northern sites to provide warning of the approach of Soviet intercontinental ballistic missile systems.

I had always wanted to teach, but when I was at Hopkins the Dean wanted me to work on his research project in high-current electric arc discharges rather than teach. I finally got the opportunity to teach when I approached the electrical engineering department at Northeastern University in Boston, when I worked at Lincoln Lab. They had a large and successful graduate evening program for part-time students. I asked about teaching a course and the chairman of the department said that they had an opening for a course on radar. Although my work in proximity fuzes and electronic countermeasures introduced me to the basics of radar, I was really not a radar person at that time. I quickly said that I would like to do it. Teaching a course on radar at Northeastern University probably was the major factor that led me to a career in radar.

After the first year of teaching the radar course I received a telephone call from McGraw Hill Publishing Co saying that they heard I was writing a book on radar. When I said that I wasn’t, they replied that they had seen a copy of the outline for the book and would like to publish it. What they saw was the revised outline for my course at Northeastern. The McGraw-Hill editor suggested that I write a book based on the course outline, which I did. The result was the text Introduction to Radar Systems, first published in 1962. It’s now it its third edition. Writing the book helped me learn a lot about radar.

Until I came to the Naval Research Laboratory I didn’t work exclusively on radar. Although most of my work at MIT Lincoln Laboratory in the late 1950s was concerned with radar, I worked in other areas including a communication system for interplanetary spacecraft.

ECI and IDA employment

Skolnik:

When I left Lincoln Laboratory in 1959 I returned to Baltimore to work for the same person, Donald D. King, whom I used to work for at the Johns Hopkins Radiation Laboratory. He was then the head of the Research Division of Electronic Communications Inc (ECI), which is now part of Raytheon. There I learned about antennas and phased arrays and many other interesting things. Radar was only one of my responsibilities, as was electronic warfare. I then joined IDA (Institute for Defense Analyses) in Washington. This was a “think tank” providing technical advice for the Office of the Secretary of Defense, DARPA, and other government agencies. IDA was an interesting place to work. It had outstanding people in many diverse fields of technology with whom to interact and it was close to the “decision makers” in the Department of Defense. At IDA I was involved with the Nike-X (a ballistic missile defense system for defending the US from intercontinental ballistic missiles), methods for penetrating foreign ballistic missile defense systems, electronic countermeasures, and a little bit of radar.

Geselowitz:

What year was that?

Skolnik:

That was 1964 and 1965.

Radar Division, Naval Research Lab

Superintendent position

Skolnik:

Then the job of Superintendent of the Radar Division at the Naval Research Laboratory (NRL) in Washington opened up and two friends recommended my name. I applied and was pleasantly surprised to be awarded the job. This was the first job where my responsibilities were solely with radar. And that’s how I got into the field of radar.

Geselowitz:

Was the Superintendent job a lot of paperwork? In other words, did you still get to do a lot of hands-on engineering at that point?

Skolnik:

The job of Superintendent had administrative responsibilities, but you were also responsible for the technical output of the Radar Division and interacting with sponsors. It allowed me to continue to grow technically by being associated with a fine group of productive radar engineers and it also gave me time to pursue my own technical interests. I wrote, on average, about one NRL technical report a year, which I really didn’t have to do but I just wanted to do. I also wrote papers for presentation and publication, which Division Superintendents seldom do. When I was interviewed for my job nobody asked me about my ability to be a bureaucrat. Instead I was asked, “How many papers did you publish?” After starting the job, I learned that a large part of the job was dealing with the bureaucracy or with “people problems,” something I was not prepared for. But you quickly learn. I became very friendly with the head of personnel at NRL who, at that time, was more than the head of personnel. In practice he was the major advisor to the Commanding Officer. He taught me how to be a bureaucrat, and I think I eventually became a successful one. I found out “bureaucrat” was not a pejorative. To be effective in the job, one has to know how to be a good bureaucrat.

Geselowitz:

So it’s almost like a Chief Engineer kind of job?

Skolnik:

Not really, it was a line type of job, a Senior Executive Service position. Chief engineer would be more like a technical advisor.

I came to NRL in the fall of 1965, and I retired March of 1996. I still work part-time as a reemployed annuitant to do things I couldn’t do when I was Superintendent.

Influential radar technologies; Over-the-Horizon (OTH) radar, ocean surveillance

Geselowitz:

While we’re talking about the work you did at the Research Lab, what are some things of importance in terms of the technical history of radar? Because you said once you came here, it was strictly a radar job. You didn’t do as much of the countermeasure work. The job here was strictly a radar job, so what were some of the high points of the history of radar that you were involved in?

Skolnik:

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When I received a letter saying, “Would you like to apply for the job of Radar Division Superintendent?” I thought, “Do they still do radar at the Naval Research Laboratory?” I knew what they did in World War II, and I knew a few people there but not well. When I came to NRL, I was impressed with what was going on. There were a number of important things that the Radar Division was involved with. What surprised me the most was the work on HF over-the-horizon (OTH) radar, which was a well kept secret since I had not heard of their work in this area previously. In World War II, the British went to war in 1939 with a 30-megahertz (HF) line-of-sight radar. That’s how they successfully fought the Battle of Britain against the German air raids of London and other British cities during the late summer and early fall of 1940. No other country in WWII ever used such a low-frequency for radar (for good reason); but as Watson-Watt, the inventor of UK radar, once said, “Give them the third best to go on with; the second best comes too late, the best never comes.” The British quickly found they had to use a very low pulse repetition frequency to avoid receiving ground echoes from 1,000 to 2,000 miles away from the radar energy refracted from the ionosphere, returned to earth, and then reflected back to the radar via the same path. But it wasn't practical to utilize such long ranges for aircraft detection at that time because of the large echoes from the ground. What NRL was able to do in the early 1960s was figure out how to separate the aircraft echoes you want to see from the large ground echoes you don’t want. Other organizations had tried to make a long-range OTH radar, but NRL succeeded. When I arrived at NRL, there was a highly successful program being conducted in HF OTH radar. They were able to detect aircraft at ranges an order of magnitude greater than could microwave radar, as well as detect ballistic missiles and ships. NRL also demonstrated with OTH radar the measurement of the strength and direction of the surface winds over the ocean at very long range. I estimate that perhaps ninety-five percent of what's known about over-the-horizon radar was first done at NRL. The current interest in HF OTH radar is its highly successful use for drug interdiction obtained by three US Navy ROTHR systems that cover the southern approaches to the US.

Much of the basic work that was done by NRL with HF OTH radar was utilized by the Air Force as well as Navy, and was adopted and extended by the Australians. They have a different defense problem than the US because they have a very large unprotected coastline. They need to know what’s approaching their borders from the vast waters surrounding their island country, which over-the-horizon radar does quite well.

Another area that NRL was a major player in was space-based radar for ocean surveillance. When I arrived at NRL in 1965, the Air Force had a program for putting military people in space, a program called the Manned Orbital Laboratory (MOL). The Navy was involved with MOL to pursue ocean surveillance, which is the detection, tracking, and recognition of ships on the oceans of the world. It was quite ambitious in that astronauts were to stay in orbit for a month, as I recall. and there was going to be a large number of launches. This was in the middle 1960s. To make a long story short, the program collapsed of its own weight. The goals of MOL would be a tremendous commitment of resources even with today’s space technology. The MOL program, however, sparked the Navy’s interest for world wide surveillance of the oceans from space using unmanned satellites. There were extensive analyses of various options for spaceborne ocean surveillance radar and some of the critical technology was flown in aircraft to demonstrate feasibility. Ocean (ship) surveillance from space is probably the most cost-effective application of spaceborne radar for military purposes. Many organizations, including the Navy, have also considered using spaceborne radar for aircraft detection and tracking - for example, a spaceborne AWACS - but it’s just pushing the envelope of practicality too far. I don’t think the use of spaceborne radar for aircraft detection will be cost-effective in the foreseeable future based on current capabilities, although that doesn’t stop many from trying.

Geselowitz:

Now why did over-the-horizon dry up?

Inverse synthetic aperture radar (ISAR)

Skolnik:

Because much of the work in radar at NRL is what is called Exploratory Development (in DoD language, it is Category 6.2). Basic research (Category 6.1) involves mainly scientific investigations. Exploratory development, on the other hand, is more application oriented and is what one does to show the feasibility and value of some new technology or system concept. Once you go beyond exploratory development leading to production there has to be an approved military requirement. So once we are able to show that something like HF OTH radar can do an important job, NRL management does not like to play a major role in its procurement and deployment. At this stage the work is turned over to some other laboratory or center which is more experienced in procurement procedures than NRL. In the case of HF OTH radar, it was the Air Force that provided most of the funding for NRL, and it was the Air Force rather than the Navy that decided to enter into the procurement of such adars for oversea operations as well as for continental air defense. Both of these Air Force applications no longer exist. The main interest now in OTH is for drug interdiction, which employs adars (known as ROTHR) originally developed by the Navy. NRL at one time had a branch of thirty people (which is large for NRL) dedicated to over-the-horizon radar R&D. Today there are only a few engineers at NRL still involved in OTH. There were a number of other radar developments in addition to OTH radar that we pioneered in, but later withdrew after we demonstrated success and the Navy was ready to go into production. We then went on to other challenges.

An example of another highly successful Exploratory Development effort that NRL pioneered in was the use of inverse synthetic aperture radar, or ISAR, for the recognition of ships at long ranges. To explain ISAR, first let me briefly describe synthetic aperture radar, or SAR, which has been known ever since the 1950s and was developed mainly by the Air Force. A SAR provides a high resolution image of a fixed scene, such as the surface of the earth and what's on it. Synthetic Aperture Radar images are not like optical pictures because of the large difference in wavelength between microwaves and optics. SAR, however, sometimes can allow one type of object to be distinguished from another (a water tower from a small building, for example). So it was thought SAR might be useful to image ships in order to recognize one class of ship from another, which is a part of target recognition. It was soon found out from tests of SAR at sea that SAR processing can significantly distort images from moving and "twisting" ships. After many attempts at trying to use SAR for ship recognition, NRL finally was able to eliminate the problem of imaging moving ships by actually taking advantage of the ship’s motion to provide resolution in the doppler domain (from which high resolution in the cross-range dimension could be obtained). This is known as ISAR. In the military, target recognition is quite important. You can’t fire a weapon until you’re sure that the target is a hostile.

NRL did the basic ISAR exploratory development work, but there was also important contractor help. Texas Instruments played a vital role in the development of flyable hardware as well as in contributing many other things involved with the technology. ISAR has been operational for a number of years in the Navy on the P-3 aircraft and previously on the S-3 aircraft. ISAR provides a capability not available previously nor available with any other sensor.

The ISAR radar flying in Navy aircraft was originally designed as a submarine periscope detection radar in the 1960s. NRL did the basic work in periscope detection in the late 1950s and early 1960s. When NRL later learned how to employ ISAR for ship recognition, the airborne periscope detection radar was readily modified to perform the ISAR task as well. Over time, ISAR for ship recognition has probably been more important than the radar’s original task of periscope detection.

Military applications, Identification Friend or Foe (IFF)

Skolnik:

NRL was involved for a long, long time, ever since World War II, in what is called IFF (Identification Friend or Foe). This is a cooperative identification system where you basically ask the question, “Who are you?” And the answer is something like (but more precisely) “It’s Charlie - don’t shoot.” IFF is a critical part of combat identification. The civil air traffic control radar beacon system (ATCRBS), so important for safe air travel, directly comes from the military IFF system.

Geselowitz:

One interesting thing is that radar today is so ubiquitous, and not just in the military. You just mentioned that military IFF led to civilian application in air-traffic control. Even though there’s not really an issue of friend or foe, I think it’s more of an issue of whether the person is supposed to be in the airspace or not—rights of way and that sort of thing. I’m sure there’s a lot of research going on to be prepared for the next military necessity, but it seems to me today that a lot of what was developed from World War II is now used in the civilian sector. So, did you have some leeway? Were you always thinking about a particular military application when you began the exploratory development phase?

Skolnik:

As a military laboratory we almost always have some particular military application in mind when we engage in exploratory development, but we don't need an approved official military requirement as is needed in order to begin procurement for the Fleet. There was no official requirement for over-the-horizon radar when we started. The same was true for ISAR and many other things we have done. Even in basic research, the work has to have some potential relevance for the military. Otherwise the work would best be supported by the National Science Foundation instead of the Navy. Consider, for example, our interest in understanding the physics of the radar echo from the sea. A long time ago we learned how to empirically design adars that operate over the sea so as to detect desired targets (such as aircraft, ships, periscopes, and swimmers) in spite of the accompanying large echoes from the sea that can seriously interfere with target detection. But we’d like to understand how the sea reflects a radar signal. None of the many different theories proposed in the past to explain sea echo do the job. One problem is that you have to understand the small scale nature of the sea to explain the radar sea echo. This means understanding the structure of the sea which is comparable in size to the radar wavelength.

Hydrodynamicists, however, have little interest in the small scale structure of the sea since their interest is with the big waves that affect ships. Radar people are interested in small structure (small waves) because that’s what affects the radar. With a radar signal having a 3-centimeter wavelength (a so-called X-band radar), it is sea waves with 1.5 centimeter wavelength that cause the echo. Since hyrodynamicists and oceanographers are seldom interested in such small waves, it is the radar engineer who has to become involved to obtain answers not otherwise available. Similarly, we also have done work in understanding how the atmosphere (including birds and insects) affects the radar echo.

To return to the question, although we may sometimes appear to be working far from our mission, if we do it's because we have a pretty good idea it will eventually benefit the Navy.

Which leads me to another thing. There is a backlog of capabilities in the technical pipeline today that could be used for improved Navy capability but is not being used because it has always been difficult to initiate new things. Usually it takes a catastrophe to occur before one gets new things done. In the past the Navy had to be forcibly dragged to accept steam, the aircraft carrier, Polaris submarines, and the now-famous Tomahawk missiles fired from ships. The Navy wanted none of these things originally, but once they had them they quickly learned to love them. The message is, it is difficult to get a new and significant capability to the Fleet.

In exploratory development and basic research, if one out of ten projects gets to be eventually used, I think that's pretty good. But Congress is seldom satisfied with such odds - they want ten out of ten.

Geselowitz:

Right. Unless presumably it’s in their district, and then the development itself is giving jobs.

Skolnik:

I hope I didn’t say that!

Geselowitz:

Right, that was the interviewer, not the interviewee. Is any 6.1 research done at NRL?

Skolnik:

A large part of NRL performs 6.1 research. It is basically a Research Laboratory. There are many Divisions here which do mostly basic research, and NRL has a healthy budget in this area. I don’t know what it is now, but when we had 3,200 total employees, there were about 450 people-years of basic research. Of the 1,200 scientists/engineers that were here, a third or more were involved with basic research. They work in such areas as semiconductors, plasma physics, chemistry, biomedical, space science, materials, oceanography, and optics. In most Divisions they look for practical applications of their research that eventually will benefit the Navy.

Ballistic Missile Early Warning System at Lincoln Lab

Geselowitz:

Before coming to NRL, either up at Lincoln or at some of these small private companies in Baltimore, were there any important developments that you had a part of that you would like to mention in the history of radar?

Skolnik:

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Yes, but let me first describe a unique and highly significant accomplishment in radar that is not well known, that I observed others doing at Lincoln Lab and General Electric rather than something I was a part of myself. For a long time the AN/FPS-17, as the radar was called, was highly classified. It can now be discussed since a radar engineer, Major Johnson (his first name is Major) at General Electric Co. in Syracuse, N. Y. wrote a book on the history of the Aerospace Group at General Electric that included the story of the AN/FPS-17. It was the only case I know of where a major new radar system significantly different from any prior radar went from idea to operation overseas in about nine months. In the early Fall of 1954, some at the Pentagon began to worry that the Soviets were soon to be testing ballistic missiles in Russia at a site called Kapustin Yar, located 75 miles east of Volgograd in Russia. After some brief “back of the envelope” calculations, a letter-contract was sent to General Electric at Syracuse N.Y. to build and install a new kind of radar, different from any radar up to that time. As I recall, its range had to be about 900 miles, as compared to the 200 mile range of then-current adars, and it was to be built in a remote region of Turkey. Nine months later, on June 1, 1955, it was operating at its remote site. In order to meet this unusually short schedule much red tape had to be broken, including having the entire radar of over 400 tons transported by an air-lift that was said to be second in size only to the 1948 Berlin airlift. This was a phenomenal task that, as far as I know, has never come close to being duplicated. Also, this was the first operational radar to employ pulse compression, which was accomplished by MIT Lincoln laboratory in about nine months. Things like that don’t happen anymore. Today it takes about fifteen to twenty years from the time somebody asks if it is possible to achieve some new military radar capability to the time it is available in the hands of the troops for operational use.

As I mentioned earlier, when I first joined Lincoln Laboratory in 1955 I was part of a small group that developed the bistatic radar, known as the AN/FPS-23, for use in the Distant Early Warning (DEW) Line located across the northern part of Alaska and Canada. As the work on the DEW line was coming to completion, the Pentagon began to be concerned about the threat of Soviet intercontinental ballistic missiles (ICBM) attacking the US and putting at risk the B-52 bombers that were the US’s means for retaliating against - or deterring - a Soviet attack. The US didn't have ICBMs at that time and they needed to have a means of warning of a Soviet attack in time to allow the B-52s to take off before the arrival of Soviet missiles. Lincoln assembled a special group of about 20 people to look at how to warn of a Soviet ballistic missile attack. From that effort came what was called BMEWS (Ballistic Missile Early Warning System) located at three northern sites, in Alaska, Greenland, and the UK.

There were no preconceived ideas of how this should be done. Among other things, I chaired a fairly sizeable ad hoc committee to examine a large number of different antenna types before we chose the one that was eventually used. This was about 1956 and even at that early time there was much interest in industry to construct phased array antennas. They were considered, but Lincoln decided the technology was not ready and instead suggested the use of a fixed parabolic torus antenna, which I believe was 230 ft high by 420 ft wide fed by a mechanically moving feed with what was called an organ pipe scanner with a revisit time of 2 s. (This was the original Lincoln design; the operational system had a slightly smaller antenna.) It would take another ten years before practical phased arrays were ready for operational use.

Lincoln Laboratory determined the type of radar suitable for the BMEWS system, a radar quite different from anything built previously. Contractors bidding on the construction of the radar did not have to follow what Lincoln had done, but the winning contractor did because it was the most cost-effective and reliable approach and had been well investigated and evaluated before the request for proposals was issued. We don’t do this anymore; that is, have an independent non-profit organization quite familiar with radar determine what type of radar that industry should build. Those organizations that know how to best build a radar, or any other piece of equipment, generally are not the best ones to determine what to build. Similarly, those who are best at determining what type of radar the military needs are generally not the best ones to build it. It requires two different types of engineering organizations to perform these two distinct functions. Unfortunately, the Defense Department no longer makes such a distinction and it is unlikely that the highly successful procedure used by Lincoln Lab to conceive of BMEWS will be repeated.

At Lincoln Lab I learned not only about radar technology and systems, but I also learned about the "sociology" of getting something done in radar, because there were a lot of experienced people at Lincoln who were from the old MIT Radiation Laboratory that conceived and developed over 100 different radar systems during the pioneering days of World War II. The five years I spent at Lincoln were highly beneficial for my future career in radar. I learned that MIT always wanted to be the best in whatever they did. That’s a nice attitude, because if you’re not the best, you’re at least the third best or the fifth best, and so you’re still pretty good rather than just getting by.

OTH R&D, Airborne Warning and Control System (AWACS)

Skolnik:

Let’s go back to OTH, because there are some further things that ought to be mentioned. When I came to NRL the Air Force, not the Navy, was the biggest sponsor of OTH R & D there. The Navy was not interested in over-the-horizon radar, but the Air Force was. They wanted long-range OTH adars for air defense of the continental US. Up to that time (the mid 60s), there were about two hundred long-range microwave adars throughout the country to defend the US against relatively slow, propeller-driven Soviet TU-4 aircraft. (Actually, the real threat to the continental US at that time was not manned aircraft but Soviet intercontinental ballistic missiles.) It was expensive to operate this large number of radar stations, so the Air Force decided they could do the same task of controlling the air-defense battle with relatively few aircraft, each carrying a long range radar. The defending interceptor aircraft would remain on the ground until warning of an approaching attack was received. The warning radar aircraft were called AWACS (Airborne Warning and Control System). To alert the AWACS to become airborne, there were to be a number of HF OTH adars located to cover the borders of the US, except the northern border with Canada. The idea was that when the OTH radar detected an aircraft that could not be identified by the time it reached a predetermined range, a long-range interceptor (which was never built) would be directed to the unknown aircraft to see what it was. If it were a threat, then the AWACS would rise up and the air defense would be conducted by the AWACS.

In the middle of the AWACS procurement, Continental Air Defense Command, which was responsible for air defense, said they no longer wanted AWACS and wanted to terminate the program. The Tactical Air Command (TAC) stepped in and said they would like to take over AWACS but as a tactical system rather than a strategic system. And that’s how AWACS became the AWACS of today.

Geselowitz:

So, it actually grew out of a strategic plan.

Skolnik:

Yes.

Geselowitz:

Wow. Most of the technology was already developed within the context of that strategic plan?

Skolnik:

Yes. And the technology needed for AWACS was exceptional. Before AWACS and the Navy’s E2 AEW aircraft, the US and the UK tried to put relatively conventional adars in aircraft to detect other aircraft. Such adars were built and flown but they could not cope with the large amount of ground and/or sea clutter echo that was seen by a radar that flew at high altitude. Such adars didn't work well. It wasn’t until radar people learned how to make a successful pulse doppler radar, such as is now in AWACS, that aircraft could be seen from the air in the midst of heavy ground clutter. The Air Force conducted a large program to find the best solution. Three different approaches by three different contractors were funded and demonstrated. Westinghouse, now Northrop Grumman, won the competition for what is now the AWACS radar.

Although AWACS was transferred to the Tactical Air Command from Continental Air Command, the Air Force continued to develop the HF over-the-horizon radar that was supposed to warn of hostile aircraft approaching the US. Let’s come back to the Soviet missile test site at Kapustin Yar I mentioned previously when discussing the AN/FPS-17 radar installed in Turkey in 1955 to detect the testing of Soviet ballistic missiles. There was another missile test site that the Air Force wanted to look at, but with a HF over-the-horizon radar known as the AN/FPS-95. It had to be installed in England. There were several basic problems that surfaced: (1) the range required was slightly greater than normal for an OTH radar; (2) unanticipated propagation effects occurred because of the long range; (3) there were questions about the suitability of the particular radar design, which increased cost and risk, and (4) the Air Force did not appreciate that more R &D was required to iron out the problems with this considerably different approach to OTH radar. The radar was built and underwent testing, but it was not able to perform as desired in the time allotted. The program was then shut down. Incidentally, the NRL Radar Division was directly involved with the year-long testing of this radar and had a contingent of its best OTH radar engineers at the radar site during the test period. In spite of the setback with the AN/FPS-95 the Air Force still remained interested in OTH radar for continental US air defense. So, they kept pursuing this type of radar.

In the early 1970s (I am not sure of the exact date), the Air Force approached their Chief of Staff with a proposal to develop a new OTH radar system for the defense of the continental US. The adars were to be located at three sites. The cost was far too high and the proposed program was rejected. About a year later they came back to the Air Force Chief of Staff and said they had a breakthrough in OTH radar technology and that the cost would be considerably cheaper, about 20 to 25 percent of the previous year’s cost, as I recall. The “breakthrough” the Air Force OTH radar proponents claimed was an FM/CW radar (a continuous wave radar with frequency modulation) rather than the more usual pulse radar. (FM/CW radar was not really new. It actually predates pulse radar.) The introduction of a lower cost system based on the FM/CW radar resulted in the AF Chief of Staff giving approval for the procurement to proceed. The revised proposal, however, was cheaper not because of a “new” technology but because (1) its costs were based on it being constructed as an R&D system rather than an operational system, and (2) only two sites, instead of three, were to be built. Some of us believed that an equivalent FM/CW system was actually more costly than a pulse system since two widely spaced sites were required for a FM/CW system (the cost of a radar site can be a major part of the system cost), and a FM/CW radar requires a larger dynamic range and better clutter attenuation than an equivalent pulse radar. Nevertheless, the East Coast OTH system was built in Maine, but never became operational. It was shut down just after the radar was turned on. Thus the Air Force OTH program ended, which was probably just as well since the threat of a large number of manned bombers attacking the US was quite remote.

As mentioned previously, the Navy also developed a HF OTH radar, known as ROTHR (relocatable over-the-horizon radar). Although NRL was the pioneer in OTH radar and demonstrated its feasibility and operational utility, OTH radar was not of interest to the Navy. The Department of Defense, however, thought that the Navy should have an OTH capability and was probably a dominant factor in the Navy eventually acquiring OTH adars. There is an interesting story as to how it came about that the Navy acquired OTH radar. I mentioned spaceborne radar previously. The Navy R&D establishment was much more interested in spaceborne radar than OTH radar. Although the Navy’s original interest was for the surveillance of ships on the oceans of the world, they were far more interested in radar for the almost unobtainable application of aircraft detection and tracking worldwide from space. In the late 1970s the Navy issued a request for proposals for a system to detect and track aircraft on a global basis. The work statement, however, was written in a general way and did not specify a spaceborne system, although everyone knew that was wanted. The contractors bidding on this procurement submitted their proposals. Although the laws of physics were not violated, the cost of such a system was quite large and its risk was unusually high. Someone then showed how an HF OTH system could perform the same task of global air surveillance that was being asked for in the procurement that was supposed to produce a spaceborne radar system. Even though twenty-four or twenty-five (as I recall) HF OTH radar sites were required to cover the world, it was considerably cheaper than performing the equivalent task from space. With encouragement from DoD, the Navy had to bite the bullet and instead of going into space, they began development of an HF OTH radar system known as ROTHR. The ability to relocate was inserted by some Admiral in the approval chain who wouldn’t approve the procurement if these very large adars were fixed and couldn’t be moved. Several ROTHRs were built and, as mentioned, three are now located to detect drug traffic from entering the US from the south.

Military R&D, labs

Geselowitz:

You were talking a little earlier, before the tape ran out, about the politics. To the outsider, it seems awfully close here. You’re closer than all the installations up in Maryland. You’re right here across the river.

Skolnik:

We might be close physically to the Pentagon Navy Management and the Navy System Commands, being right across the river; but it is a mighty big river to cross from the point of view of the chain of command. The Naval Research Laboratory reports to the Chief of Naval Research, who is head of the Office of Naval Research, an Admiral with two stars - sometimes only one star. The Army and Air Force usually have three-star generals in similar positions. Decisions in the Navy seem to be more influenced by those who perform acquisition rather than R&D. The Naval Research Laboratory is, in some respects, more like a “job shop.” We receive a budget for basic research that is basically under the control of the laboratory, but for almost everything else we have to go out and write proposals and find sponsors. We aren’t a line item in the Navy budget.

Geselowitz:

So you’re talking about in-house sponsors. You have to go to a certain branch of the Navy and say, “Gee, if we knew about this, that would help your ships.”

Skolnik:

Yes. However, there are difficulties since for many of the new things we’re interested in there is no desk in the Pentagon or the Systems Commands where somebody thinks they have responsibility. A good example was when we tried to get the Navy interested in HF OTH radar. There was no Navy requirement to see targets at 2,000 miles. With most of the things that we do we have to get the requirement generated as well as sell the technology. Even if somebody likes what you’re doing, it might take three years to get into the budget before you can start to really begin procurement.

Geselowitz:

What were some of the other labs that were doing radar in that period throughout the DOD in the ’60s and ’70s? Was it mainly done here?

Skolnik:

Lincoln Laboratory has always been a major power in radar because they have a large number of good technical people and, probably just as important, they have maintained good connections with the Pentagon. Their management has been able to get the big sponsors like DARPA to put big money into Lincoln. That’s what you have to do. In the 1950s though the 1970s’s they were probably the major player in radar. They seemed to do less radar work later on until Bill Delaney became Assistant Director and brought radar back to life at Lincoln. If you want something smart in radar, that’s a good place to go.

The Jet Propulsion Lab (JPL) in Pasadena California, which is supported by NASA, has done outstanding work in spaceborne radar for remote sensing and planetary observation. For example, I believe it was remarkable what they did with the Magellan radar that orbited Venus to obtain radar images of the planet’s surface underneath the opaque clouds that always surround Venus and prevent optical observation. They perfected the use of interferometric synthetic aperture radar to obtain three-dimensional measurements of the surface of the planet. I was very impressed with what JPL did in planetary exploration, including the Cassini mission now enroute with a radar to observe, underneath the clouds, the surface of the moon Titan that rotates around Saturn. JPL has an outstanding group of radar people out in Pasadena.

Most of the radar R&D at Navy laboratories has decreased significantly. The Naval Air Warfare Center at Warminster, PA, that did airborne radar development, was closed. In the 1960s and 1970s, the former Naval Electronics Laboratory in San Diego had a small but very productive Radar Division that did very good work. They did an outstanding job in the 1990s in understanding radar propagation over the ocean and in providing the tools (in the form of computer programs on CDs) that allow the Fleet to determine how the ocean environment affects radar and communications systems in the real world. It was a great accomplishment, but they do very little in radar development now. The Naval Surface Warfare Center at Dahlgren, VA, also did some very good radar work in the past, but most of their efforts now are in support of the acquisition part of the Navy rather than R&D. In the past, Navy laboratories, other than NRL, reported to and served one of the Navy System Commands. It was a good arrangement. Then they were called “Centers” rather than laboratories, and their R&D mission was reduced as they provided more effort in support of the acquisition process. Their job is to not to do basic research or to spawn new development, but to get things into the Fleet. The Johns Hopkins Applied Physics Laboratory (APL) used to do more in radar, but they’re not that way now. Their mission is more to support the Fleet and the acquisition process rather than to do research and development. Thus, NRL is unique in having as its mission the performance of research and development. That is the good part, but the bad part is that NRL is relatively disconnected from those in the Navy who make the decisions about what the future Navy will be like.

Evolution of radar research, 1940s-1990s

Skolnik:

Beginning in the early nineties, there was a major change in radar caused by the downsizing of the military establishment and industry that resulted from the end of the cold war. This loss was aggravated by the retirement of the generation of engineers who entered radar shortly after World War II. In the late 1940s and in the 1950s radar was the new thing that attracted the interest of electrical engineering students, based on the favorable publicity it received after its successful introduction in World War II. Many engineers working in radar during that time had served in WWII and eagerly wanted to work in this hot new field. When I came to work at NRL in 1965, there were experienced people in the Pentagon whose job it was to review everything the Navy proposed to do that was related to radar and make sure that it was okay before it could be approved. They’re gone. There were people in the various Navy Systems Commands who were knowledgeable in radar and who initiated radar programs. They’re gone.

Geselowitz:

Well, I guess the first generation came in just before World War II. It was coalesced by World War II, the Rad Lab people. They all retired, and now the next generation came in, in the wake of World War II and they’re now retiring. Radar, even though you say there’s things still in the pipeline, I guess somehow it doesn’t seem cutting edge. We take it for granted, even though it was such a miracle during World War II?

Skolnik:

There is something to that.

Geselowitz:

The big thing is people are looking somewhere else.

Skolnik:

When I was a graduate student in the late 1940s, most of us wanted to work in microwaves when we graduated rather than in power engineering which was the field of interest of most of the electrical engineering faculty. Things change and now almost everyone wants to work in computers. As early as the early 1970s, people in the Pentagon would say to me, “NRL has done a lot of good work so there doesn’t seem much more to do. You’ve done it all, so we probably should reduce your funding next year.” The several times this happened I have sat down and written a paper demonstrating why radar is not a mature field. With the downsizing in the 1990s, the merger of many defense companies, and the loss of experienced radar engineers there has been a reduction in what is being done in radar. However, there are some interesting and important areas of activity.

Weather radar

Skolnik:

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Probably the most important advance in radar in the 1990s was in weather adars. The portion of the nightly news devoted to weather seems to be dominated by displays of the output of the Nexrad doppler weather radar. Those involved in weather radar are a different radar community from the military radar community. A major weather radar conference sponsored by the American Meteorological Society has been held every year and a half for about forty-five years now. Many papers are presented and they publish a book of “preprints” that is quite thick even though each paper is only three or four pages in length. Although a military radar engineer usually understands the importance of the doppler frequency shift in a radar, the weather radar engineers seemed slow to take advantage of this important characteristic of a radar echo. They finally did, and the result is the Nexrad doppler radar. There are about 150 of these adars, mostly covering the US. What you see on your TV weather report, however, is only one of about 30 different Nexrad “weather products” that the meteorologist uses to determine what is happening with the weather.

Sometime during the middle of the Nexrad procurement, a meteorologist at the University of Chicago identified a severe weather effect called a downburst which can seriously affect aircraft as they land and take off. Investigations of the history of aircraft accidents showed the downburst was the major cause of weather-related aircraft accidents. On average, the downburst caused a fatal aircraft accident about every two years. Unfortunately, the Nexrad radar was not effective in detecting these dangerous downbursts even though some Nexrad systems were installed by the FAA near airports. Nexrad takes five to ten minutes to make its observations, but a downburst lasts only about two minutes. Therefore, Nexrad cannot guarantee that a dangerous downburst will be seen in time. This deficiency was corrected by a new radar specially designed to detect the downburst. It is called the Terminal Doppler Weather Radar and is now installed at or near major airports.

One weather radar you seldom hear about is the Wind Profiler, a doppler radar that looks up and can measure the wind speed and direction. You are probably aware that meteorologists routinely launch balloons lifting weather instruments. They are tracked either optically or with radar to determine wind speed and direction as a function of height. I believe weather balloons are launched from about 300 sites throughout the world twice a day. The wind profiler, on the other hand, can produce a measurement of the wind every ten minutes. In the mid-west US there are about thirty wind profiler radar sites. In addition to the National Weather Service, such information about the wind is used by the airlines to determine the quickest routes from one point to another. The doppler wind profiler actually obtains its radar echoes from the clear air.

The Australian HF over-the-horizon radar known as Jindalee, mentioned previously, can determine the surface winds over the ocean. They send this information to their weather service on a regular basis. There is also a weather radar satellite flying called TRMM. It was actually started by the Japanese, but it is now a joint Japanese and US (NASA) endeavor.

To return to the Terminal Doppler Weather Radar, pilots don't usually like somebody on the ground telling them what to do, such as “don’t continue to land - go around.” There are now airborne weather adars in the nose of commercial aircraft with doppler weather processing that allow the pilot to determine if there is dangerous wind shear present when he or she is landing or taking off.

Geselowitz:

On the newscasts you see your local radar, you see the clouds shot. I don’t know what the distance is, but it’s got to be 400 kilometers. From New York, I see the clouds.

Skolnik:

The range of a Nexrad is 230 kilometers for doppler processing and 460 kilometers for non-doppler (conventional) processing. What is seen on your TV screen is usually a composite of many weather adars throughout the US, unless your local TV station has bought its own doppler weather radar, as many have done.

Geselowitz:

Right. Integrated by computer.

Skolnik:

There is one aspect of Nexrad I might mention that's not well known. During the time of the Nexrad procurement process, the program office was having trouble. The program manager wasn’t answering his mail. Congress was asking questions and they weren’t getting answers. The General Accounting Office (GAO) was asking questions. Because of the lack of communication, Congress was threatening to terminate the program.

Geselowitz:

What does Nexrad stand for?

Skolnik:

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“Next Generation Radar.” In the mid 1980s, there were two major radar companies being funded to develop competing designs for Nexrad. It was a competition to determine which company would be selected to manufacture the radar. The government’s estimate for the cost of the radar was a little over four million dollars each (and 144 were to be manufactured). There was a small company called Enterprise Electronics located in Enterprise, Alabama which made a fine, but smaller, doppler weather radar that they sold to many TV stations and weather research organizations in the US and abroad. As I recall (but I'm not sure) the cost of their doppler weather adars at that time was from $150,000 to $250,000. They configured a design that they said would do the Nexrad job at a cost of about one million dollars per radar, as best as I can recall. The million dollar Enterprise radar, however, did not do everything required by the procurement specifications for the four million dollar Nexrad. The company went to Congress and in essence said something like, “Why don’t you buy our radar for a million dollars instead of the four million dollar adars you expect the Nexrad systems to cost?” They were able to obtain a letter signed by a large number of Congressmen endorsing their lower cost “Nexrad” proposal. An almost equal number of Congressmen signed a different letter recommending the original Nexrad program be continued unchanged. There seemed to be misunderstandings and poor communication among the Nexrad Program Office, Congress, and the customer for the radar. In addition to the National Weather Service (the part of NOAA which was in charge of the procurement), the Department of Commerce, the Defense Department, US Air Force, FAA (Department of Transportation), and OMB were also concerned about the procurement of Nexrad, which further added to the confusion. Even the Inspector General’s office of both the Department of Transportation and the Department of Defense became involved. Nexrad was in serious danger of being terminated.

I was then asked by NOAA to organize a committee of radar and weather radar experts to try to straighten out the problem and get the procurement back on track. I was able to assemble a highly competent group of radar engineers and radar meteorologists to establish the facts and make recommendations. An unusual thing, however, was that I was to be the vice-chairman rather than the chairman. The chairman was to be someone by the name of Ray Kammer. He played no part in selecting the committee members, but joined the committee as chairman at its first meeting. At the time, he was Deputy Director of the National Bureau of Standards. As you know, this is a highly respected scientific organization. I believe Ray Kammer was in his forties at the time. He had no Doctor’s degree or any degree in science or engineering. His undergraduate work I believe was in economics. This might seem strange, but I mention it to indicate how naturally talented Ray Kammer was as a technical administrator and problem solver. He was a highly exceptional person and did an excellent job in running this important committee at a crucial time in the development of Nexrad. At the beginning he mainly listened and let the technical people on the committee do the talking and ask the questions of the contractors. Kammer made sure that all those organizations that were concerned either pro or con with the Nexrad procurement were invited to the committee meetings. He knew his way around Congress and he took me to meet every staffer in Congress who had an issue with the Nexrad program. This was very important and something unusual for me, since as a DoD employee I am not allowed to talk with Congress without getting approvals all up and down the chain of command. But this was a Department of Commerce issue, and they operated with Congress quite differently. By the time we were ready to report to the Congressional Committee that had the responsibility for Nexrad, Kammer asked me to accompany him to sit at the witness table to address any technical issues he could not handle. I never had to intervene, which is unusual for me. He did an impressive and beautiful job – which resulted in the Nexrad program getting back on track and becoming what you see today. The government could use many more administrators with the talent and dedication of Ray Kammer.

Before turning to another subject I would like to mention something more about that little company in Alabama that helped to cause the commotion with Nexrad. I had never heard of them previously, but I quickly became highly impressed with them as I talked with their engineers and learned more about what they did. Enterprise Electronics Corporation was located in Alabama, near Dothan (the city that proudly calls itself the peanut capital of the world). Although relatively small, Enterprise was a highly innovative company that produced a fine line of low cost weather adars that were used throughout the world. They were not successful in challenging the Nexrad procurement since the specifications would have to be reduced, which the Program Office and buyers didn’t want to do.

Army radar R&D, Fort Monmouth

Geselowitz:

In terms of other labs, I know that up by us in the New Jersey area is the Army Signal Corp Electronics Lab at Camp Evans, which did a lot work. During the War, they were involved with the SCR 268 and 270, then after the War with Project Diana. Did they keep up in radar?

Skolnik:

I believe the Army installation in New Jersey you mention is more often known as Fort Monmouth. As you said they did some fine work in radar; but for some reason the Army didn’t want to maintain radar R&D at Fort Monmouth. Eventually much of the Army radar work went to Huntsville, Alabama. I never understood why they wanted to reduce the radar effort at Fort Monmouth since they had some very highly respected radar engineers there. The Army is different from the Navy in how they manage technology. I am not sure how they operate at present, but in the past Army officers ran the laboratories, not just as commanding officers but as heads of the technical organizations within the laboratories. The Navy laboratories, on the other hand, are largely run by civilians, although the executive head (the Commanding Officer) is a naval officer.

Geselowitz:

They hire civilian experts and they trust them to some degree.

Skolnik:

I'm not knowledgeable enough to respond to your comment. Someday someone should write a paper on the differences - and there are major differences - in how the three military services manage their R&D. Maybe such diversity is good, and maybe not.

Geselowitz:

They keep an eye on them, but they give them something.

Skolnik:

I get the impression that the Air Force goes out of its way to make its military who are involved in R and D knowledgeable. They will keep their military longer in a technical job than does the Navy or the Army. The experience they get by staying on the job longer is quite important.

Professional communications across labs; IEEE

Geselowitz:

I may segue into something about the IEEE. How easy or hard was it for these different labs to communicate? Especially within the Navy, but, God forbid, across service lines?

Skolnik:

Not hard at all, when it's at the technical working level. People outside the system usually think communications among laboratories doesn’t exist. They might see a project that we were doing at NRL and a related project that someone else was doing in Rome, New York (Air Force) or Huntsville, Alabama (Army), and conclude there was duplication. But we usually knew what the others were doing and it wasn't duplication. We might have been trying to solve a similar problem, but we were doing it in different ways and usually with different external constraints because of the different ways each Service does its job. The IEEE AES [Aerospace and Electronic Systems Society] Radar Systems Panel is representative of the radar community in this country, and to some extent in the world because some of its most active members are from outside the US. In fact, one of our British members is now on the Board of Governors of AES. In the classified area there are regular exchanges of information with the United Kingdom, Canada, Australia, and New Zealand and representatives from each of the US military services. There is also a classified TriService Radar Symposium held annually with sponsorship rotated among the three Services and there are NATO conferences on radar and related subjects. The communication problem is not that we don't know what is going on in other Services, but has been in getting the message of the technical radar community to a higher (decision) level in the military management chain where actions can be taken. In World War II this problem didn't exist in the US because civilians seemed to have more control of the direction of military R&D. If you look at the history of military technology in WWII, you will find that those countries which had civilians in control of the new directions in technology (the UK and the US) were far more successful in introducing new technology as compared to the totalitarian countries (Germany, Japan, and Italy) where the military were in direct charge of R&D.

Geselowitz:

Did the special technical societies of the IEEE (which in 1962 was formed from the prior AIEE and IRE) help both in terms of publications, conferences, and panels within the technical community?

Skolnik:

Absolutely. If a radar engineer has a paper to publish, he usually submits it to the AES Transactions because that's the major publication for radar papers. The AES is very important for the radar community.

Geselowitz:

That also helped, assuming with civilian transfers to the civilian sector and also for you to know what the civilian, what the weather radar people were doing and so forth. If it wasn’t classified or trade secrets they would publish.

Skolnik:

There have been some weather radar papers in IEEE publications, but weather radar scientists tend to publish much of their work in the Bulletin of the American Meteorological Society.

I would like to mention the role of the AES Radar Systems Panel beginning when Dave Barton became its chairman. Before Dave, the Panel was not very active. I'm not sure I even knew any of the members. When he became chairman he revised the Panel membership by bringing in those active in radar, especially those with a record of publications or leadership. The Radar Systems Panel initiated the International Radar Conference that is held in the US every five years. In the intervening years it started the annual Radar Conferences, formerly known as the National Radar Conference. There is an annual award for the Young Radar Engineer of the Year. It now has a Warren White Award for major accomplishments in radar, which is named to honor one of the pioneering radar engineers who recently passed away. I believe that the AES and its Radar Systems Panel have helped in a major way to enhance the efforts of the radar community.

Comparison of US and Soviet Union Cold War radar research

Geselowitz:

Just to complete the circle on the technical history, was there a parallel radar history of the Soviets during the Cold War? We were doing stuff. Some was classified; some was presumably not quite classified and got into the civilian sector. But presumably they were off on their own trying to do their own thing. Did they do any developments in the last ten years since the fall of Communism that we’ve said, “Oh, that’s good. Let’s use that”?

Skolnik:

It has to be appreciated in the US that the Soviet Union went its own way in radar. After WWII they said they didn’t want to copy the US since that meant they would always be behind. They had a very large effort in radar. Sometimes we would see things in Soviet radar we didn’t understand because they didn’t solve the problem the exact same way we might have. A good example was the Soviet ABM system that they installed around Moscow in the mid 1960s. It was not at all like the US Nike-X ABM system we were developing in the same time period. This is an interesting story, but perhaps too long for this oral history.

Starting right after WWII the Soviets developed a wide variety of adars for military purposes, most of which were different from US designs for similar applications. With the collapse of the Soviet Union, their economy didn’t seem to be able to support the same degree of military R&D as previously. Previously, Soviet radar engineers seldom published in the open literature or presented papers at international conferences. This has changed and one sees far more Russian and Ukrainian papers on radar than before.

Geselowitz:

Again, not to stereotype the technological style of the society, which is something we can do, it seems like I’ve seen a number of instances very recently and with what you just said about their solution, where they really had a different approach. Our approach seemed to be to find an elegant solution, and theirs sometimes seems to do more of a brute force. I don’t mean that in a negative way like unthinking brute force, but more like rather than doing more basic research and solving this problem cleverly, if we do more of this what we know how to do, we can beat it.

I went to a talk by the guy who’s in charge of the International Space Station for coordinating us with the Russians, and he was trying to cheer us up that they’re behind in budget and schedule on their part of the module. He was saying that we have these batteries that are much longer lasting, but what they do is they put six backup batteries in parallel, and so when one goes it doesn’t matter. Then I had an oral history interview today with Brad Parkinson, who is considered the father of GPS. He told me the Russian Glonass system is really quite impressive, but it jumps through all these hoops to not be quite as good as our GPS system. In other words, they solved the problems, but they did it in a different kind of way.

Skolnik:

That’s right, the Soviets solved their problems in their own way. For example, their spaceborne electronics might not have been as small as US space electronics, but they were able to build large booster rockets to carry the space payload – which we didn’t seem to know how to do. Their bigger boosters meant they could put up heavier payloads. So we had to be more sophisticated with our electronics. It’s just a different approach. In the computer field the Soviets were said to be behind the US in processing hardware, but they seem to make it up with better software. When you compare US and Soviet systems the comparison should be on how well each system does the intended job, not how small or large or pretty it might look.

The Soviets fielded their version of the US Patriot land-based air-defense system (the SA-10) before the US did, and went on to develop three other systems. They fielded their Aegis shipboard air defense system (SAN-6) before we did. In 1993 Dave Barton was invited to the Moscow Air Show to examine the Russian SA-12 air defense system. He wrote an article in Microwave Journal in May 1994 which discussed how Soviet radar design differed from, and in some ways was better than, what the rest of the world did. To further illustrate how they do radar differently from the US, consider their wide use of long-range VHF air-surveillance radar. The Russians published a paper on their VHF adars in the June 2000 issue of AES Systems Magazine, which I encouraged them to write. The article said that they produced over the years 20,000 such adars, some of which were sold to other countries. They pointed out that they have a very large country, so they can’t afford expensive adars. Hence they chose to build the less expensive VHF adars to cover much of their vast country. The US has not had VHF radar for about 40 years. VHF is not a good frequency choice for the US (for one reason, the many FM and TV stations in that part of the spectrum), but VHF radar solved the needs of the Soviets fine. Other examples can be mentioned where Soviet systems look different because their needs are different from ours. Thus each country solves its problems in its own fashion. One has to respect the Soviet adars. However, just as in the US, the generation that developed such adars has retired. Because of their economic problems, there hasn’t been that much new in radar from Russia or Ukraine in recent years to judge the new generation of radar engineers. But the same can probably be said of the current generation of US radar engineers.

Geselowitz:

But they have people going into it? Because you were saying earlier that American engineers all want to be computer engineers.

Skolnik:

I don’t know. I haven't met the current generation of Russian or Ukrainian radar engineers, but I don’t really know the current generation of US radar engineers either. But it should be noted that one doesn’t have to be an old person to do good things in radar or any other field of technology. A good example is that of the MIT Radiation Laboratory where microwave adars, which never existed previously, were developed for use by the US and its Allies in WWII. Although the Radiation Lab developed over 100 different types of adars for military use during the five years of its existence, no radar experts were ever hired to work there. None existed because it was a new field. The new employees were made into radar experts on the job.

Geselowitz:

They created the experts.

Skolnik:

That’s right. And they were all relatively young people. Those in their forties were the “senior citizens.”

Influential radar work, publications, and societies

Geselowitz:

Right. Looking back over your career in the history of radar, are there any individuals you think ought to be singled out, either that are already sung or unsung that were key figures in the history of radar?

Skolnik:

Oh, I would hate to do that in such a short time, but you will notice that a large number of the IEEE AES Pioneer Awards are for radar.

Geselowitz:

All right. I won’t force you.

Skolnik:

With regard to radar outside of the US, it should be noted that Europe has been improving its capability in radar. It used to be that Europeans, especially NATO countries, would follow the US lead. This is beginning to change somewhat. One of the most innovative European radar companies was the Dutch company Signaal. They sold their adars throughout the world. Even though their adars were well advanced in technology and innovative in concept they didn’t first make an R&D model. Their first radar of any new design was always sold. Recently Signaal was bought up by Thales, a relatively large company, and it is now known as Thales Nederland. Most of Signaal’s previous management and creative engineers are now retired so I am not sure that Signaal is the same as it used to be. Ericsson in Sweden has produced some unique adars, not found anywhere else in the world, such as a small airborne early warning radar and an ultrawideband VHF airborne SAR for ground and foliage penetration. The Israelis have a wide variety of advanced adars and their approach to radar is different since their needs are different from those of other countries. Another interesting radar company is Alenia, formerly Selenia, in Italy. At one time they probably made the best air-traffic control adars in the world, as well as other fine military adars; but they have also experienced management changes. In addition to the Russians, other countries in Europe with significant radar capability include the UK and France. I am not aware of a large radar manufacturing capability in Germany, but the publications of their radar engineers certainly indicate that they have a good knowledge of radar.

Geselowitz:

You mentioned historically that if you wanted to publish in radar you published in the IEEE Aerospace and Electronic Systems Society, their Systems Magazine or their Transactions. And you mentioned that the Russians are separate; you mentioned the IEE, that the British had their own journal. Would you say, by and large, that today internationally the AES is where people publish? Like the Dutch and the Swedes?

Skolnik:

The AES Transactions might be the major US source for papers on radar, but there are others outside the US. The AES Transactions publishes four issues a year with – as a guess – perhaps a total of 30 to 40 papers per year on radar. In the UK, one of the IEE Proceedings is devoted mainly to radar and is published six times a year. They might also have from 30 to 40 papers a year devoted to radar. I have been told there are some US radar people who prefer to publish in the UK because they believe the IEE has better refereeing of papers than does the AES Transactions.

It seems the Chinese probably have published more papers on radar in recent years than the radar engineers of any other country. Steve Johnson, a member of the AES Radar Systems Panel, arranged for the AES Transactions to publish more than twenty pages listing the titles of Chinese papers on radar. They seem to have looked at everything in radar, but I don’t know if they have built very many of their own adars.

Geselowitz:

How about the Microwave Theory and Techniques Society of IEEE. Do many radar papers end up there?

Skolnik:

Not usually, because MTT people are interested in the little nitty-gritty things. They appear to be more interested in the components and subsystems of radar than the radar system itself.

Geselowitz:

Not the big systems.

Skolnik:

Yes. Even historically, there has not been that much MTT interest in radar. They do, however, recognize that radar is an important electronic system that depends on microwave technology. They are having a special issue the year after next [note inserted in editing: it came out in May 2002], and I have been asked to write a paper, “The Role of Radar in Microwaves.” They see radar as a place for their product to go to. But there isn’t that much on radar in their Transactions.

Geselowitz:

Is that the same, would you say, with the Antenna and Propagation Society? Some of them are working on microwave antennas, and they might send the antenna off to a radar person, but they are interested in just the configuration of antennas, independent of what the frequency is or what it is used for?

Skolnik:

There seems to be more of interest for me in the APS than in the MTT. I am still a member of Antennas and Propagation Society, but I gave up my MTT membership perhaps twenty years ago.

There is also a radar interest in the Geosciences and Remote Sensing Society. They publish papers on the use of Synthetic Aperture Radar and other applications of radar in remote sensing of the environment.

Geselowitz:

So again, as I have heard from various people I’ve interviewed, what makes AES special is the fact that it is a complex system that has to do something in the real world. We’re talking about radar systems here, but there are other kinds of systems that AES people do. But the reason that they are in AES and not in all these other societies that are out there is this is a society that says, “Okay, you’ve got this complex system. You have to power it. Pieces of the system have to intercommunicate, they have to interface with the real world,” and so forth.

Skolnik:

Let me get parochial about “systems.” The electronic, electromagnetic, or electrical system is the basis for electrical engineering. Without the system, you don’t have need for anything else in the IEEE. What is a computer unless it is used as an information system, or a control system, or a signal processing system? So what AES does is the heart of all electrical engineering. I teach a graduate course in radar, which is designed to be systems-oriented because most undergraduate and graduate students don’t know what a “system” is, how you go about configuring one, or how systems developed by electrical engineers work. So I think AES is one of the more important of the IEEE Societies because it is concerned with the heart of what we are all about.

Geselowitz:

That’s true. Since I have a slight background in electrical engineering, you learn these bits and pieces, and then you get out to the real world on a bench, and that’s when you all of a sudden realize that this circuit and this circuit, which both look good on paper, have to somehow work together to do some greater function. You’re never prepared for that in school. Not usually.

Teaching

Skolnik:

Let me give you an example from when I was teaching my evening radar course in Boston at Northeastern University. At one time I taught the course to a class with only employees of Raytheon, a major radar company. I was talking about FM/CW radar one night. I didn’t want to say too much about some of the more detailed aspects because the HAWK air defense system (which had been developed and manufactured by Raytheon) was a good example of an FM/CW system. I thought the students would be familiar with it. In trying to motivate the class I said something like “FM/CW is the basis for the HAWK air-defense system.” The brightest student in the class raised his hand and said, “I work on the HAWK, but I don't know what it is. Could you tell me about it?” That is the case all too often.

Geselowitz:

You have mentioned that you always thought that you wanted to do teaching and you didn’t have that many opportunities. During that Lincoln Lab period you had an opportunity to do the teaching. Have you managed to keep up teaching since then?

Skolnik:

Yes, since 1955 I have taught a graduate course in radar each year. What bothers me is I still like to do it. The course has changed quite a bit, but the basics don’t change that much.

Geselowitz:

Where have you taught most recently?

Skolnik:

Since 1970 at the Johns Hopkins University. They have a large part-time graduate program for the Master’s Degree in all aspects of engineering. It is run basically by APL people.

Geselowitz:

Do they get a lot of military people there?

Skolnik:

Well, they attract people from Fort Meade which can be military, and the old Westinghouse (now Northrop Grumman), but the students come from all types of engineering companies. Before the downsizing in military activities in the early 1990s my radar course was usually one-third from Fort Meade, one-third from Westinghouse, and one-third from almost everywhere else in the Baltimore-Washington area. With the downsizing, the enrollment in part-time graduate programs also decreased. Now that the next generation of engineers after the downsizing is starting to appear, the enrollments in part-time courses are increasing again. But the students are a little different. They have had a heavy emphasis in computer studies, which is good; but this has been at the expense of an appreciation of the systems of which the computers are a part.

I also have taught short courses at George Washington University and for other organizations. When I used to teach the short courses on a regular basis I probably had more class-room hours with students than do most of the full-time faculty in a “research university.” So yes, I enjoy the teaching in addition to my regular work. It keeps me up to date.

AIEE, IRE, and IEEE activities

Geselowitz:

Can you remember when you first joined IEEE?

Skolnik:

When I was a freshmen at Johns Hopkins in 1944 I joined the AIEE as a student member. The Institute for Radio Engineers (IRE) was not as strong at that time. Only one professor was a radio engineer, the rest were interested in power. I joined the IRE when a graduate student in 1947.

Geselowitz:

Other than the publications or first readings and later publications, did you have any activities in IRE or IEEE?

Skolnik:

I was on the Proceedings Editorial Board, and then I became the editor for four years in the late 1980s. I was a member and at one time the chairman of the AES Radar Systems Panel.

Geselowitz:

How did your involvement with the Proceedings come about? Did someone ask you?

Skolnik:

When a member of the IEEE Proceedings Editorial Board leaves, he or she suggests the one to take his place. Prof. Ishimaru of the University of Washington recommended I take his place when he left the Board. The managing editor of the Proceedings, Reed Crone, who was a long-time employee of the IEEE, was the one who selected me as the editor.

Geselowitz:

Did you enjoy that?

Skolnik:

Very much. It also gave me a chance to learn something about the management of the IEEE Headquarters, which was then in New York.

Digital technology and radar

Geselowitz:

Well, okay. I think we have covered a lot of interesting ground. Is there anything else you would like to have on the record, so to speak, before we end the interview, that you think we didn’t cover?

Skolnik:

Well, we covered a lot, but there has been much left unsaid. Nothing has been mentioned as to how the revolution in digital technology, that began in the early 1970s and is still continuing, has been responsible for almost all of the major advances in radar for the past 30 years. I tried to talk about radar in general rather than concentrate only on what happened in radar at the Naval Research Laboratory. There is also one particularly unique, interesting, important, and (to some extent) disquieting experience with radar that was conducted over a period of many years, and which has not been touched on here at all. To me it is probably the most important thing I have done in radar, but its telling has to await another time and place.

I think radar is a very important system application of electrical engineering. Almost every aspect of electrical engineering enters into radar. There is still a lot more out there that can be done and I hope that it will eventually happen.

Geselowitz:

Great. Well, thank you very much, Merrill.