Defence Research and Development Laboratory

About: Defence Research and Development Laboratory is a facility organization based out in Hyderabad, India. It is known for research contribution in the topics: Turbulence & Mach number. The organization has 404 authors who have published 420 publications receiving 4183 citations. The organization is also known as: DRDL.

Effect of rocket exhaust of canisterized missile on adjoining launching system

Abstract: Transient numerical simulations are carried out to study missile motion in a vertical launch system and to estimate the effect of missile exhaust in the adjoining launch structure. Three-dimensiona...

Synthetic Aperture Radar : A Focus on Current Problems.

Abstract: Synthetic aperture radar (SAR) is a powerful tool for mapping and remote sensing. The theory and operation of SAR have seen a period of intense activity in recent years. This paper attempts to review some of the more advanced topics studied in connection with madern SAR systems based on digital processing . Following a brief review of the principles involved in the operation of SAR, attention is focussed on special topics such as advanced SAR modelling and ffocussing techniques, in particular clutterlock and autofocus, Doppler centroid (DC) estimation methods involving seismic migration technique, moving target, biststic radar imaging , effects of system nonlinearities,etc.

Frequency domain input identification for vibration testing of flexible structures

Abstract: Electronic equipments in flexible slender aerospace structures are subjected to severe vibration environments during the course of flight. In order to qualify the equipment for real life environment, they are subjected to vibrations levels using electrodynamic shaker tables on ground. Control sensors are placed at the critical locations and desired spectra are achieved on the electronic packages at the section level testing. During this testing, the flexible modes of the structure are ignored. In this present study, a methodology of vibration testing is described to achieve the desired spectra at the specified locations on the structure. The article discusses a frequency domain identification of the required input forces to achieve desired acceleration spectra at the specified control locations on the structure. A generalized formulation of input force identification for multiple input multiple output is presented for the vibration testing methodology. Three different configurations like single input sing...