A. S. Bugaev

Bioradar for monitoring of human adaptive capabilities

This paper sums up the results of bioradiolocation experiments dedicated to the monitoring of human adaptive capabilities, which were conducted at Remote Sensing Laboratory (Bauman Moscow State Technical University) during last two years. The main task of bioradiolocation is remote or non-contact measurement of movement, breathing and pulse parameters of biological objects behind an obstruction or in open space at some distance. This method can be used in sleep medicine, functional diagnostics, pharmacology, zoo-psychology, restorative medicine and disaster medicine. Description of the bioradar experimental procedure is given.

Automated data acquisition system for holographic subsurface radar

Manual data acquisition with holographic subsurface radar is quite tedious as it requires monotonous scanning with precise positioning at the beginning of each scan line and requirement to move along straight lines to obtain a microwave hologram. A good result with manual scanning requires some practice, which still leaves such difficulties as maintaining constant press to evade image interlace and rapidly degrading performance of the operator. To address these issues an electromechanical scanning system equipped with holographic subsurface radar is considered in the paper. The system allows automated acquisition of microwave holograms over an area with maximum dimension 77 by 84 cm and gives reproducible results through precise positioning. The scanning is performed with an adjustable distance to the surface without direct contact. The influence of a gap between scan plane and the sounding surface is later compensated by hologram reconstruction technique. The main mechanical and electronics components of the system are described as well as driver control strategy. A selection of acquired images is presented. The system is shown has significant increase in performance over manual scanning and recommended for automated data acquisition with other types of contact sensors.

Microwave holography in detection of hidden objects under the surface and beneath clothes

Proposed in the article design of a continuous wave radar with programmable frequency switching and quadrature receiver is targeted as base component to a variety of radars: ground penetrating radar, body scanner, and bio-radar. Algorithms of reconstructing holograms are outlined for planar and circular apertures. High achievable resolution is demonstrated in experiments involving measurements and reconstruction of holograms in air and opaque media.

Detection of mine-like objects in high-resolution aerial images

A system for mine detection in aerial images is considered as an interactive system in which the operator is responsible for making iterative queries to the database of images and analyzing the results. Preliminary, each image undergoes formal decomposition into a set of feature vectors. Each feature vector is calculated for every irregularity found at a scale-invariant salient point detection stage where a blob detector is used. Assuming that every small object in the image can be described by a single invariant feature vector calculated on a patch around the salient point, formalization of search algorithms is feasible. While the template-based search is straightforward in the terms of one object - one feature vector, we focus on another important option when searching for mines - similar object search. For similar object search a hierarchical clustering algorithm is considered. The mentioned steps of image processing as well as similar object search are illustrated by performing on aerial mine field images taken by an electronic camera from a height of 27 meters. Encouraging preliminary results lead to the formulated plan for future research. The developed algorithms are planned to be used in an image search engine allowing the operator to interactively search for mines in a database of aerial images in humanitarian de-mining operations.

Non-linear instability under resonance

The nonlinear instability threshold of acoustic modes being in phase synchronism with exchange spin modes has been investigated experimentally. Experiments were made in planar ferrite film - dielectric substrate structures in the range of magnetic fields and frequencies where exchange MSW (spin-wave resonances) are in phase synchronism with transversal acoustic waves (i.e. spin-wave resonances have the same wavelength as transversal acoustic modes wavelength). Strong oscillations of the nonlinear threshold has been revealed in the narrow range of the spectrum which are due to strong reconstruction of the spectrum which results in reconstruction of the each mode and the secondary waves modification.

Interaction of magnetoacoustic waves with flux-line lattice in superconducting-ferrite layered structure

We consider vortex lattice interaction with transverse surface magnetoacoustic wave in high- Tc superconductor--ferrite structure. It has been found that the magnetoacoustic waves excited in the ferrite can be efficiently coupled with vortex structure in superconducting film. The nonlinear effect of vortex drift as well as the possibility of the wave amplification are discussed.