DOI:10.1049/ree.1971.0106

出版商:IERE    

年代:1971

数据来源: IET

摘要:

The installation of a complex electronic scanning sonar in a fishery research vessel is described. It includes a versatile hydraulically-operated stable platform to which the electroacoustic transducer is attached. Problems of electrical and acoustic noise are discussed in relation to detection ranges. Applications include fish detection and fish behaviour studies, observations of trawls both in midwater and on the seabed, detection and classification of wrecks, and studies of sand waves and other seabed features, including detailed survey of gravel extraction.

DOI:10.1049/ree.1971.0107

出版商:IERE    

年代:1971

数据来源: IET

摘要:

An ultrasonic radar simulator has been built for the production, at reasonable cost, of the large quantities of data required for the evaluation of radar system performance. A fully automated short range simulator is described together with its mode of operation. The manual long-range system is also described together with studies, at present in progress, aimed at automating this work.

DOI:10.1049/ree.1971.0108

出版商:IERE    

年代:1971

数据来源: IET

摘要:

The programming of a small digital computer (8k store) is described for use in conjunction with a network analyser. The object was to remove automatically from swept-frequency measurements of microwave admittance the effects of loss and reflexion due to transitions between the network analyser and the device or circuit under test, as well as various intrinsic errors arising within the analyser. The work is divided into two phases, the first of which pertains to loss-less junctions only and ignores intrinsic errors in the amplitude of reflexion coefficient. In the second phase, which introduces a number of refinements, the scattering parameters of an equivalent error network are evaluated and by using these a more complete system of error correction is achieved.

DOI:10.1049/ree.1971.0109

出版商:IERE    

年代:1971

数据来源: IET

摘要:

Describes a new approach to deriving an algorithm which allows the completely automatic computation of root-loci sections at high speed. The storage requirements are very small and the program can be run on a 4k, 12-bit word computer using FORTRAN 2, together with a cathode-ray display, probe and tracker board.

DOI:10.1049/ree.1971.0110

出版商:IERE    

年代:1971

数据来源: IET

DOI:10.1049/ree.1971.0111

出版商:IERE    

年代:1971

数据来源: IET

DOI:10.1049/ree.1971.0112

出版商:IERE    

年代:1971

数据来源: IET

摘要:

The magnitude and direction of horizontal ocean currents are measured as a function of depth by a new free-fall instrument utilizing geomagnetic induction. Electric fields are induced within the instrument and the surrounding seawater due to motion through the Earth's magnetic field. The instrument measures the induced electric field, pressure and temperature and acoustically telemeters this data to the ship. With this instrument the structure of ocean currents in a vertical profile can be studied in great detail.

DOI:10.1049/ree.1971.0113

出版商:IERE    

年代:1971

数据来源: IET

摘要:

This paper describes a new graphical method for analysing the transient phenomena of some important non-linear lumped parameter networks as well as simple transmission line networks. The method is based on the approximation of the lumped networks by ideal homogeneous transmission lines. The transient behaviour of the transmission line circuits is then obtained by graphical means from the finite difference equations describing these networks. A number of examples such as a tunnel diode oscillator, a π-equivalent pulse transformer circuit and others, illustrate the method. The graphical approach is extremely well suited for investigation of various sine-wave and square-wave oscillators, monostable and bistable circuits, as well as simple transmission line circuits.

DOI:10.1049/ree.1971.0114

出版商:IERE    

年代:1971

数据来源: IET