DOI:10.1049/ree.1979.0106

出版商:IERE    

年代:1979

数据来源: IET

DOI:10.1049/ree.1979.0107

出版商:IERE    

年代:1979

数据来源: IET

DOI:10.1049/ree.1979.0108

出版商:IERE    

年代:1979

数据来源: IET

摘要:

The Global Weather Experiment now drawing to a close has depended heavily on observations made by meteorological satellites in obtaining weather information from both Hemispheres. The roles played by theMeteosatandTiros‘N’ systems are described in broad detail and a preliminary assessment of the meteorological data points the way to future improvements in weather forecasting techniques.

DOI:10.1049/ree.1979.0109

出版商:IERE    

年代:1979

数据来源: IET

摘要:

The most important property of a television system is the quality of the received picture as judged by the user. An explanation is offered of the way in which human beings quantify picture quality and the apparent magnitude of picture impairments. Although the explanation is speculative, it is hoped it will prove intuitively attractive, and will assist both the interpretation of the results of visual subjective studies and their application in terms of objective measurements. The psychological scale of apparent magnitude turns out to be also the scale along which co-existing impairments may be simply summed to determine their total effect. It is thus closely related to the IMP scale which has already found practical application.

DOI:10.1049/ree.1979.0110

出版商:IERE    

年代:1979

数据来源: IET

摘要:

This paper deals with the design of simple, and relatively inexpensive, dedicated equipment which is tailored to test a 6th-order analogue pitch rate compensation unit using sweep frequencies and return signal processing to estimate gain and phase characteristics. It is shown that the test time required for an optimum swept frequency test compares very favourably with the total test time needed using either automatic test equipment or manual steady state testing at a few frequencies. The test technique provides a ‘hard-copy’ signature of the system under test in a form which has found particular favour for maintenance purposes in such diversified areas as electronic circuits, aircraft structures, and air breathing systems. The technique should be regarded as complementary to more flexible frequency domain test methods in forming the complete inventory of equipment needed during system life-cycle testing.

DOI:10.1049/ree.1979.0111

出版商:IERE    

年代:1979

数据来源: IET

摘要:

During 1977, BBC Research Department was invited to participate in field trials of an experimental optical-fibre digital transmission system installed between the Post Office telephone exchanges at Hitchin and Stevenage. BBC equipment was specially adapted for these trials to provide multiplexed digital video and audio signals at 140 Mbit/s and to decode these signals after transmission.High-quality audio and video signals were sent between Hitchin and Stevenage, a total distance of some 18 km for the return path, over a period of one month during which time a number of tests were conducted. Brief descriptions of the equipment and tests are contained in this paper. No serious difficulties arose in the trials.

DOI:10.1049/ree.1979.0112

出版商:IERE    

年代:1979

数据来源: IET

摘要:

The harmonic heterodyne frequency measuring technique described here provides wide f.m. tolerance, high sensitivity and automatic amplitude discrimination. It requires only one microwave component—a sampler—and uses a microprocessor to perform the required computations. This minimizes the hardware content and facilitates data manipulation.

DOI:10.1049/ree.1979.0113

出版商:IERE    

年代:1979

数据来源: IET

摘要:

This paper describes an efficient method for the implementation of digital filters with special-purpose hardware. The second-order section is realized by applying the canonic form algorithm in conjunction with two's complement serial arithmetic. The pipeline implementation was used for high-speed performance. The objectives were to obtain a cascaded cellular structure with small circuit complexity and well suited for practical I.s.i. realization. The derived cellular filter is a functionally complete second-order section, that is, it provides the arithmetic operations, the delay requirements and the rounding using only one control signal. Also, it is expandable and permits flexible filter design. Higher-order digital filters can be obtained with repeated use of the proposed second-order section.

DOI:10.1049/ree.1979.0114

出版商:IERE    

年代:1979

数据来源: IET