We examine thermal effect of a 2.1 tm Holmium laser on the internal stress and shape of cartilage. For 2.1 microns radiation, the absorption depth is more by an order of magnitude than that, for 10 jim radiation. We have studied the influence of laser intensity, pulse duration, pulse repetition rate, and of cartilage thickness on its shaping conditions. Spatial and temporal locality of Ho laser radiation as well as the bulk character of the heating allow to produce the stress relaxation without overheating of the surface irradiated and to prevent undesirable effects of tissue carbomsation and destruction.
The article deals with the estimation of the radial velocity when using a coherent burst of radio pulses as applied to the presence of correlated fluctuations of the initial phases in the radio pulses reflected from the target. The accuracy of the measurement of the burst frequency is evaluated for case of coordinated processing without taking into account the phase fluctuations. The signals at the input of the radar's receiver is an additive mixture of signals reflected from the targets, and uncorrelated Gaussian noise, that is the assumption of investigating. It is assumed, that the phase fluctuations of the received radio pulses bursts are distributed according to normal probability laws with zero mean, and correlations of phase fluctuations decrease with exponential or alternating, sign-variable laws by increasing interval between radio pulses within the bursts. This analysis makes it possible to determine the conditions under which the complication of the processing algorithm for this radar signal is considered justified. K e ywor d s : coherent pulse radar; burst of radio pulses; phase fluctuations; radial velocity; Gaussian noise; radar surveillance; optimization efficiency.
The multichannel and fixed parameters radars for tracking targets with the phased array antennas are widely used in modern military surveillance systems. The modular integration of a phased antenna array with digital processors allows to realize the command and control functions of antenna patterns for tracking multiple targets in the time resolution modes. Tracking of the air targets in range, radial speed and angular coordinates of evaluations and azimuth is provided by means of the multichannel radars without adaptation modes to the characteristics of external influences. Thus, adjusting the algorithms of tracking systems to the maximum maneuverability of the air targets can lead to a significant reduction in the accuracy of surveillance in comparison with the potentially achievable accuracy for such radars of tracking the linear flight targets in the long duration of time. In the case of adjusting the algorithms of tracking systems to either low intensity of flying targets, or lack of the aircraft maneuvering, it is possible to significantly increase the error of the aircraft flying information, and as a result to have a disruption of tracking the air targets. The increase in the parameters of the tracking error in relation to the influence of external interference were obtained as a result of the study. As a result of research, it is possible to assess the feasibility of adapting to certain characteristics of external influences, and provide recommendations for selecting and fixing the parameters of algorithms of tracking systems to ensure their versatility to surveillance targets with both high maneuverability, and implementing the stealth technology.
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