摘要:

This opening address to the Conference points out that although progress in electronics since the end of World War II has been spectacular, its performance might have been even more impressive if a larger proportion of all the prophecies which were made of new devices, techniques, materials and functions had come to pass. Some of these hoped for developments are discussed and the reasons for their unfulfilled promise suggested.Lessons learned from this study of the past include the importance of both technical timeliness and commercial timeliness and can be applied to present-day forecasts of probable developments. Guide-lines for the future include the digital concept rather than the analogue, parallelism rather than serialism; and the importance of achieving function without the limitations of circuits.

DOI:10.1049/ree.1968.0003

出版商:IERE    

年代:1968

数据来源: IET

摘要:

Ariel IIIcarries equipment from five scientific groups in the U.K. to measure ionospheric and high atmosphere properties. The project management structure is described.The spacecraft configuration evolved from two fundamental requirements—spin stabilization and power supply by solar cells. The evolution of the structure and sub-systems, together with the operation of various mechanisms, is outlined. The reliability, needed and achieved, of electronic ground equipment is stressed, and operations at the Western Test Range are discussed.The choice of orbit was a compromise between several experimental requirements and the capability of theScoutlaunch vehicle. Data acquisition and processing are discussed.

DOI:10.1049/ree.1968.0004

出版商:IERE    

年代:1968

数据来源: IET

摘要:

This paper discusses the design of an economical wideband array suitable for low-frequency radio astronomy applications. The array consists of 32 non-uniformly spaced, uniformly excited, log periodic antennae designed to operate over a 2 : 1 frequency band. At the highest operating frequency, the array has a beam-width of approximately 1°and side-lobes at least 16–5 dB below the main beam level. The theoretical limit to which the'side-lobes of an idealized array, having the same gain and length, can be suppressed is 17 dB.

DOI:10.1049/ree.1968.0005

出版商:IERE    

年代:1968

数据来源: IET

摘要:

The factors affecting the thermal design of a spacecraft are first discussed in general terms. Attention is then given to the thermal design problems onUK-3, and in particular to the difficulties associated with the gold plateand white paint which had to be used as the main thermal control surfaces. The distribution of the thermal control surfaces finally chosen is given together with the predicted temperatures for the more critical items of equipment.The form of the simulation of space heating conditions provided by the R.A.E. 1/2 metre Space Test Chamber is discussed together with the details of the trials performed on theUK-3to ensure the accuracy of its thermal design.Finally, a comparison is made between the temperatures predicted and the temperatures measured in orbit: an overall correspondence to better than 5 deg C was obtained.

DOI:10.1049/ree.1968.0007

出版商:IERE    

年代:1968

数据来源: IET

摘要:

Recent papers have described controlled shift register systems with which conversion can be made between pure binary code and 8421 binary-decimal code. This paper shows how this technique may be extended to other weighted binary-decimal codes, and puts forward a wider theory of which 8421 b.c.d. is a special case.

DOI:10.1049/ree.1968.0008

出版商:IERE    

年代:1968

数据来源: IET

摘要:

An experiment to measure ionospheric electron densities based upon the detection of permittivity changes in a parallel plate capacitor is discussed briefly, together with a method of determining electron temperatures based on the comparison of differential currents to identical probes. The application of these techniques to theAriel IIIsatellite and some preliminary results are also described.

DOI:10.1049/ree.1968.0011

出版商:IERE    

年代:1968

数据来源: IET