Defence Research Agency

About: Defence Research Agency is a based out in . It is known for research contribution in the topics: Synthetic aperture radar & Radar. The organization has 1211 authors who have published 1109 publications receiving 31542 citations.

Evaluation of an experimental high power, short-pulse radar

Abstract: This paper reports on UK experience in the trials and evaluation of an experimental I/J-Band (10 GHz) radar, using a microwave relativistic backward-wave oscillator as transmitter, generating very high peak power (500 MW) in pulses of 7 ns duration. A Russian radar experiment, using a similar generator as the transmitter, was conducted at the Kulyman test range overlooking the Ob river in Western Siberia in 1985. Under a collaborative arrangement between the UK MoD and GEC-Marconi, the main participants in the original radar programme were contracted in early 1993 to design and build a second system, incorporating improvements to the original design, for delivery to the UK as an experimental test bed.

Long term radiometric calibration of ERS-1 SAR

Abstract: Accurate radiometric calibration of space SAR is vital for several operational applications such as crop and forest monitoring, and ice classification. In particular, it is important to know whether the SAR calibration is constant over the mission life. This paper presents the results of long term calibration measurements made for ERS-1 SAR, using accurately made trihedral reflectors as calibration targets. The results show that even after correction for all known errors variations in target signatures were observed which may be attributed to variation in gain of the high power amplifier. However these variations seem to be within the overall specification of the instrument. >

The Development Status of the Space Technology Research Vehicle Programme

Abstract: In order to test in orbit a wide variety of new systems and technologies and to carry out associated research, the Royal Aerospace Establishment is developing two small 50 kg satellites, designated Space Technology Research Vehicles 1a and 1b. They are scheduled to be launched into the geostationary transfer orbit by an Ariane 4 in 1993; in this orbit they will be able to investigate the effects of a very high radiation dose, atomic oxygen erosion and spacecraft charging. The paper discusses the design of the spacecraft and describes the development status as at September 1991. Details are also given of a selection of the payload experiments.

Infrared signature visualization

Abstract: Methods for visualizing scalar and spectral measurements taken from multiple observation angles around an object are presented in this paper. Scalar data measured at varying orientation and elevation angles can be visualized in the form of a signature globe, and spectral data from different orientation angles as a ring chart. The new visualizations are contrasted with standard charting methods and are shown to supplement them considerably, presenting a clear picture of the overall thermal signature.

The use of microscopy in the evaluation of fibre-matrix interfacial properties

Abstract: SUMMARY Microscopy plays an important role in the evaluation of the micromechanical properties of fibre-matrix interfaces. The methods rely on the use of microscopy to undertake each test successfully. Physical parameters are evaluated quantitatively and the interface morphology is assessed qualitatively. This paper reviews the use of microscopy in evaluating the fibre–matrix interfacial properties of composites.