For the independent discovery of matched filtering, adaptive filtering, and high-resolution pulse compression for an entire generation of Russian and Ukranian radars.
In 1959, Yakov Shirman was awarded the “Doctor of Science” degree (the degree above the Ph.D. and only awarded to Ph.D. degree holders whose research results transfer into broad application) for his thesis “Improvement of Range Resolution without Pulse Duration Shortening.” The principles are also described in Shirman’s 1963 book Fundamentals of the Theory of Detection of Radar Signals and Measurement of their Paraments, translated into English in 1967.
Concurrent with these seminal investigations, demonstrations, and implementation of pulse compression, Professor Shirman was investigating super-resolution, culminating in 1959 with publication of his statistical theory of resolution and super-resolution. These results were generalized over spatio-polarmetric-time-frequency resolution and published by Shirman in 1961 in the context of digital and analog interference mitigation techniques. Since digital devices were too slow in 1961 to implement these techniques, Professor Shirman, inconjunction with S. I. Kransnogorov, designed an approximate analog implementation, which was an “adaptive I-Q compensator with correlation feedback,” first as a single channel (patent N296267, filed 27 Jan. 1963) and then as a multi-channel device (patent N324956, filed 2 Mar. 1963).
After prototype implementation on the P-12 radar (which showed significant removal of single (1963) and multiple (1964) jammers), as described in the 1989 paper “From the history of domestic radioengineering,” RadioEng, 1980, N11, the Soviet Academy of Science launched the “Record MO” research program. Under Professor Shirman’s leadership, different types of adaptive compensators were developed, both in the Doppler domain (for clutter mitigation) and the direction-of-arrival domain (for jammer mitigation). Together with the primary radar industrial enterprises, successful field trials were carried out for a number of different types of ground-based and airborne radars. As with Professor Shirman’s development of the matched filter, this development of the adaptive filter was conducted in the absence of any Western publication of similar capability. The paper published by B. Widrow
in 1967 (Proceedings IEEE, vol. 55) referred to a heterodyne correlation feedback compensator, invented by Howells, in August 1959 and published in 1965. By that time, Shirman’s “I-Q” type compensator had been transitioned by Fedinin and Krulov into a heterodyne type and patented. Professor Shirman’s invention, demonstration and refinement of the adaptive compensator lead to widespread implementation in a wide range of Soviet radar systems.
Late in the 1950s, the application of waveform compression was being explored for applications in passive location (signal intelligence). Technical solutions (see Kharkevich, Spectra and Analysis, 1953) considered parallel (multi-channel) or sequential (single channel) spectral analysis. But multi-channel devices were too bulky and sequential devices suffered from low-speed heterodyne tuning timeframes, when using conventional heterodyne-type receivers. The problem was solved by Professor Shirman by replacing the receivers with receivers using matched filters, matched to the frequency derivative of the heterodyne (patent N146803, filed 30 Dec. 1961). This patent (along with one by Tsurskii filed in 1965) was used in an active radar with frequency scanning, as well as passive multistatic systems. With a government initiated research program (“Okno MO”), this lead to the investigation of the use of ultra wideband waveform to achieve better radar performance in clutter and target recognition capabilities. Field trials were conducted by Professor Shirman’s group, using the height finder PRV-10 radar, but expanding the waveform bandwidth by a factor of 10. This required a new heterodyne filtering scheme, invented by Shriman in patent 25284, filed on 14 June 1962. This bandwidth extension allowed for an order of magnitude better range resolution.
In addition to these seminal contributions to the application of matched filtering, pulse compression, adaptive processing, and use of UWB waveforms, Professor Shirman continued to enhance the educational process for the next generation of radar engineers, publishing 4 major textbooks on the theoretical foundations of radar and radar warfare between 1968 and 1974. From 1975, Yakov turned his attention to the training of radar engineers in digital signal processing, publishing in 1981 his book Theory and Technique for Radar Data Processing in the Presence of Noise. From 1980, Professor Shirman remained active in a number of radar fields ranging from target recognition, noise radar, Bayesian estimation, and radar backscatter modeling. He published several books in English on these topics and continued to present at conferences on a wide range of topics, despite approaching his ninetieth birthday.
His contributions to filtering and waveform techniques were used in virtually every Soviet radar designed in the 1960s and 70s, developed independent of roughly time-coincident activities in the Western world, and now implemented digitally on virtually every radar system. Professor Shirman was among other honors, a Laureate of USSR State Premia; a Meritorious Scientist of Ukraine; and an IEEE Fellow.