Radar applications

It all started almost 60 years ago when P. Spencer, studying high-power microwave sources for radar applications, observed the melting of a chocolate bar in his pocket at least that is the story told. The first patent in this field was filed by him in 1946 and one year later the first commercial microwave oven appeared on the market. We had to wait until 1955 for domestic models, but by 1976 almost 60% of US households already had a microwave oven. 

Long decay time phosphor for use in radar applications. Green emission at 525 nmAs3+ added to promote longer decay... 

A family of vacuum-tube MMW sources is based on the propagation of an electron beam through a so-called slow-wave or periodic structure. Radiation propagates on the slow-wave structure at the speed of the electron beam, allowing the beam and radiation field to interact. Devices in this category are the traveling-wave tube (TWT), the backward-wave oscillator (BWO) and the extended interaction oscillator (EIO) klystron. TWTs are characterized by wide bandwidths and intermediate power output. These devices operate well at frequencies up to 100 GHz. BWOs, so called because the radiation within the vacuum tube travels in a direction opposite to that of the electron beam, have very wide bandwidths and low output powers. These sources operate at frequencies up to 1.3 THz and are extensively used in THZ spectroscopic applications [10] [11] [12]. The EIO is a high-power, narrow band tube that has an output power of 1 kW at 95 GHz and about 100 W at 230 GHz. It is available in both oscillator and amplifier, CW and pulsed versions. This source has been extensively used in MMW radar applications with some success [13]. 

But in real radar applications many different noise and clutter background signal situations can occur. The target echo signal practically always appears before a background signal, which is filled with point, area or even extended clutter and additional superimposed noise. Furthermore the location of this background clutter varies in time, position and intensity. Clutter is, in real applications, a complicated time and space variant stochastic process. 

But in real radar applications the average noise and clutter power level (/x) is unknown and must be estimated in the detection procedure first. This is done by several published CFAR procedures, which will be discussed in this section, where each specific CFAR technique is motivated by assumptions about a specific background signal or target signal model. 

In [28] the performance of OS-CFAR in a 77GHz radar sensor for car application is examined. In the automotive radar application case multiple target situations occur almost always. 

The military has had SiC on its radar screen for many years for radar applications, electronic warfare, more electric airplanes, more electric ships, more electric combat vehicles, and rail guns (which, we suppose, are also of the more electric variety). These applications require high-quality materials and large wafer sizes. Thanks to the military and its requirements for large wafers of high quality, the... 

From this discussion, it should be obvious that the two most important properties of cathode-ray phosphors are the response to electron-beaun excitation (brightness) and the decay time. We require a long-decay phosphor for radar applications and a short-decay phosphor for television usage. Nearly all the cathode-ray phosphors are based on the zinc and cadmium sulfides because they exhibit the highest efficiency to cathode-ray excitation. ZnS forms a series of solid solutions with CdS whose emission band can be shifted from the blue (ZnS Ag) to the red phosphor. 

K. Maatta, J. Kostamovaara, A high precision time-to-digital converter for pulsed time-of-flight laser radar applications, IEEE Transactions on Instrumentation and Mesurement 47, 521-536 (1998)... 

Ground penetrating radar applications in paleolimnology. Brian J. Moorman... 

The microwave and radar applications are in the form of yttrium-iron garnet (YIG) and its aluminum counterpart yttrium-aluminum garnet (YAG), which is used for lasers. 

Geoff A. Burrell Leon Peters, JR. 1979. Pulse propagation in lossy media using the low-frequency window for video pulse radar application. Proceedings of the IEEE, 67(7) 981-990. 

Fig. 7.3. Block diagram of the three-frequency nonlinear heterodyne system for radar application...

The three-frequency nonlinear heterodyne system can also be used for pulsed radar applications. The configuration is similar to that considered previously. Pulses are sent to the target and the maximum-likelihood test is used to determine whether the target is or is not present (reflected or scattered signal deemed present or absent). For a detailed treatment of conventional range-gated pulsed radar applications, the reader is referred to the book by Davenport and Root [7.74]. 

Much of microwave technology was developed during World War 11 for radar applications. The technology was developed secretly it became available for public use only after the war. In 1951, AT T s new microwave radio-relay skyway carried a telephone call via a series of 107 microwave towers that were spaced about 30 miles apart this was the first microwave application that could carry telephone conversations across the United States via radio (as opposed to wire or cable). The system could also carry television signals three weeks after the first telephone call, at least 30 million people saw and heard President Harry Truman open the Japanese Peace Treaty Conference in San Francisco. Then, in 1946, Percy Spencer, an engineer at the Raytheon Corporation, developed the now-ubiquitous micro-wave oven. 

Departs N, Loyez C, RoUand N, Rolland P-A (2006) Pulse generator for UWB communication and radar applications with PPM and time hopping possibilities. ISCAS 2006, pp. 661-665,2006. 

Fig. 1 presents a screenshot of the weather radar control panel, used to operate the weather radar application. This panel provides two functionalities to the crew. The first one is dedicated to the mode selection of weather radar and provides information about status of the radar, in order to ensure that the weather radar can be set up correctly. The operation of changing from one mode to another can be performed in the upper part of the panel. 

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