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The Pacific theater of World War II represents a turning point in the history of navigation: whether a ship’s commander should entrust the safety of his vessel to his own judgment based on years of practical experience at sea or rely instead on radio broadcasts, the beginnings of “big data,” and the output of detection systems, including radar. U.S. naval campaigns in the Northwest Pacific during World War II, when some of the largest armadas of naval vessels ever assembled were continuously at sea in a relatively restricted maritime area for months at a time, provide notable occasions when the old and the new knowledge were tested under extreme weather conditions and the exigencies of wartime operations. [ABSTRACT FROM AUTHOR]

The article presents an overview of research conducted on the development of camouflage coating systems in the range of ultraviolet, visible, near infrared and radar waves, as well as operational tests of these systems. Among other things, the influence of temperature on coating systems and tests in chambers with cyclically changing conditions is presented. [ABSTRACT FROM AUTHOR]

RADAR plays a vital role in military applications since its origin in the 2nd world war. Recently it has been used in surface inception, health monitoring, infrastructure health monitoring, etc. In these applications, Ultra-wideband RADAR systems are more popular than traditional RADAR systems. Impulse RADAR is a special kind of ultra-wideband RADAR, which is mostly used for surface penetration, through-wall imaging, antimissile detection, anti-stealth technology, etc. because of its high resolution and low center frequency. Out of all these applications, impulse RADAR has been used intensively as a ground-penetrating RADAR for the detection of land mines, underlying pipelines, buried objects, etc. This report has attempted to provide the steps for designing the impulse ground penetrating RADAR (GPR) as well as provides the value of crucial parameters required in the design process of commercial GPR systems. [ABSTRACT FROM AUTHOR]

An electronic warfare (EW) simulator is presented to investigate and evaluate the tracking performance of radar system under the electronic attack situations. The EW simulator has the input section in which the characteristic parameters of radar threat, radar warning receiver, jammer, electromagnetic wave propagation, and simulation scenario can be set up. During the process of simulation, the simulator displays the situations of simulation such as the received signal and its spectrum, radar scope, and angle tracking scope and also calculates the transient and root-mean-squared tracking errors of the range and angle tracking system of radar. Using the proposed EW simulator, we analyze the effect of concealment according to the noise and signal powers under the noise jamming and also analyze the effect of deception by calculating errors between the desired value and the estimated one under the deceptive jamming. Furthermore, the proposed EW simulator can be used to figure out the feature of radar threats based on the information collected from the EW receiver and also used to carry out the electronic attacks efficiently in electronic warfare. [ABSTRACT FROM AUTHOR]

Ship detection by Unmanned Airborne Vehicles (UAVs) and satellites plays an important role in a spectrum of related military and civil applications. To improve the detection efficiency, accuracy, and speed, a novel ship detection method from coarse to fine is presented. Ship targets are viewed as uncommon regions in the sea background caused by the differences in colors, textures, shapes, or other factors. Inspired by this fact, a global saliency model is constructed based on high-frequency coefficients of the multi-scale and multi-direction wavelet decomposition, which can characterize different feature information from edge to texture of the input image. To further reduce the false alarms, a new and effective multi-level discrimination method is designed based on the improved entropy and pixel distribution, which is robust against the interferences introduced by islands, coastlines, clouds, and shadows. The experimental results on optical remote sensing images validate that the presented saliency model outperforms the comparative models in terms of the area under the receiver operating characteristic curves core and the accuracy in the images with different sizes. After the target identification, the locations and the number of the ships in various sizes and colors can be detected accurately and fast with high robustness. [ABSTRACT FROM AUTHOR]

The technological development of the last decades has brought to light more and more important possibilities for improving the technologies applied in aviation. Among other things, the low-speed aircrafts can be in the near future equipped with electric engines of a totally new type. But for this, we must first establish theoretically how the direct conversion of the magnetic energy can be done and also, we have to study the properties of the magnetic materials and how they can be used in the design of a new type of a prime mover. Aviation should be one of the first areas that would benefit from the results of this research and development activity. [ABSTRACT FROM AUTHOR]

This issue's "Historical Corner" column hosts an article by Francisco Saez de Adana of the University of Alcal? concerning the history of radar from the Spanish point of view. The history of radar often attracts interest, and several articles on the topic have appeared in IEEE Antennas and Propagation Magazine, see, e.g.,: [ABSTRACT FROM AUTHOR]

In previous papers, bounds on the root-mean-square miss of a radar-guided missile for different types of target maneuvers and the terminal phase period have been presented. In this paper, bounds on the miss of multiple-model-based terminal guidance laws are presented. Analytical formulas of bounds on the root-mean-square miss of a radar-guided missile that implements multiple-model estimation and guidance scheme against a maneuvering target are presented. These formulas use a set of core parameters that affect the miss distance, thus, they can be used for synthesis and analysis of the performance of radar-guided tactical missiles with the multiple-model estimation and guidance. The bounds are derived subject to the assumption that the missile guidance law and the estimator are fully matched to the missile dynamics, target maneuver, and glint noise. The glint is the dominant noise source, the missile applies frequency agility, there is no missile acceleration limit and heading error, and there is no limitation on the computing resources. [ABSTRACT FROM AUTHOR]

In order to make full utilization of resources and reduce electromagnetic interference, integration of radar and communication on the electronic warfare platform shows great significance. Since the multi-carrier signal has been widely used in communication and also shows good performances in radar detecting, an integrated radar and communication signal based on direct-sequence spread spectrum OFDM(Orthogonal Frequency Division Multiplexing) is put forward. How to achieve the system is discussed afterwards. The ambiguity function of the integrated signal is worked out to analyze the radar characteristics in detail. The conclusions that signal resolution performance grows with the increase of the sub-carrier number and random sequence only influences adjacent channel interference of the ambiguity function define research directions to improve the signal sidelobe performance. Theoretical analysis and simulation results show that the integrated signal not only satisfies conventional radar detection but also shows good communication performance. [ABSTRACT FROM AUTHOR]

The structure of a new type of elevation-azimuth antenna pedestal which is convenient in disassembly or assembly and can be carried by single soldier was studied. Rotary table azimuth rotating pedestal and repeatably assembled pitching turntable were used in order to meet the mass requirement of every part disassembled. While the structure of the antenna pedestal was analyzed by using the finite element method, some joints like screws, pins and flat keys were neglected and the key joints were checked by theoretical formula to ensure its connection strength. The results showed that the structure of the antenna pedestal was reasonable and its mechanical property also met the use requirements. [ABSTRACT FROM AUTHOR]

The author discusses the history of the digital computer algorithms for the Ministry of Defense of the Russian Federation including the development of prototypes in 1957 under the Moscow Scientific Research Institute of Instrument Automation. He mentions the radar information processing system Mezha was developed in 1960 composed of Kurs-1 mobile electronic semiconductor, radar unit control, and power trainer. He concludes the efforts were terminated in 1987.

The Square Kilometre Array (SKA) will operate in frequency ranges often used by military radar and other communications technology. It has been shown that if extraterrestrial intelligences (ETIs) communicate using similar technology, then the SKA should be able to detect such transmissions up to distances of ~100 pc (~300 light years) from Earth. However, Mankind has greatly improved its communications technology over the last century, dramatically reducing signal leakage and making the Earth ‘radio quiet’. If ETIs follow the same pattern as the human race, will we be able to detect their signal leakage before they become radio quiet? We investigate this question using Monte Carlo realization techniques to simulate the growth and evolution of intelligent life in the Galaxy. We show that if civilizations are ‘human’ in nature (i.e. they are only ‘radio loud’ for ~100 years, and can only detect each other with an SKA-like instrument out to 100 pc, within a maximum communication time of 100 years), then the probability for such civilizations accidentally detecting each other is low (~10−7), much lower than if other, dedicated communication techniques are permissible (e.g. optical SETI or neutrino communication). [ABSTRACT FROM AUTHOR]

Louis Essen (1908–1997), working at the National Physical Laboratory in Teddington, England, was the first scientist to realize that the value for the velocity of light used widely during World War II was incorrect. In 1947 he published his first determination of it, which was 16 kilometers per second higher than the accepted value, causing a great deal of controversy in the scientific community. His new value was not accepted for several years, until it was shown that it improved the precision of range-finding by radar. Essen’s result has remained as the internationally accepted value despite a number of attempts to improve on it. I discuss Essen’s work and also examine other optical and nonoptical determinations that were made in the United States, and their limits of accuracy. I also identify the reasons why it took so long for Essen’s new value to be accepted, and how it led to changes in the definition of the units of length and time. [ABSTRACT FROM AUTHOR]

The article discusses the early use of the radio telescope at the Jodrell Bank Observatory in England as a radar early-warning system capable of detecting the launch of intercontinental ballistic missiles (ICBM) by the Soviet Union. The construction of the telescope in 1957 under observatory director Bernard Lovell is discussed, as is the British government's interest in its unique ability to track the launch of the Soviet satellite Sputnik I, and its subsequent secret role in early missile defense programs, including during the Cuban Missile Crisis of 1962.

Ground Penetrating Radar (GPR) is a promising sensor for landmine detection, however there are two major problems to overcome. One is the rough ground surface. The other problem is the distance between the antennas of GPR. It remains irremovable clutters on a sub-surface image output from GPR by first problem. Geography adaptive scanning is useful to image objects beneath rough ground surface. Second problem makes larger the nonlinearity of the relationship between the time for propagation and the depth of a buried object, imaging the small objects such as an antipersonnel landmine closer to the antennas. In this paper, we modify Kirchhoff migration so as to account for not only the variation of position of the sensor head, but also the antennas alignment of the vector radar. The validity of this method is discussed through application to the signals acquired in experiments. [ABSTRACT FROM AUTHOR]

An automatic target recognition (ATR) algorithm, based on greedy learning of Gaussian mixture model (GMM) is developed. The GMMs were obtained for a wide range of ground surveillance radar targets such as walking person(s), tracked or wheeled vehicles, animals, and clutter. Maximum-likelihood (ML) and majority-voting decision schemes were applied to these models for target classification. The corresponding classifiers were trained and tested using distinct databases of target echoes, recorded by ground surveillance radar. ML and majority-voting classifiers obtained classification rates of 88% and 96%, correspondingly. Both classifiers outperform trained human operators. [ABSTRACT FROM AUTHOR]

Focuses on several methods of identifying enemy aircraft effectively through radar systems, in which a radar signature is not available. Scheme of making a detailed radar measurement of relevant aircraft; Use of Inverse Synthetic Aperture Radar imagery of aircraft; Codes that can be used to simulate the detailed range profiles of a warplane. INSET: EMRS DTC.

Focuses on the use of multilevel agents in radar systems to improve the ability to track radar objects that prove difficult for conventional techniques. Radar systems that allow all round measurements of both the range and Doppler of targets in high-clutter environments to be made; Difficulty of distinguishing between unwanted moving targets on the ground and targets of interest with low closing rates; Key concept of a pre-track system that exploits spatio-temporal Doppler correlations to help reduce ghost targets.