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The article is devoted to the development of methods for mapping the bottom of shallow reservoirs by laser bathymetry. It is noted that the main factors influencing the depth of laser bathymetric studies are the correct choice of the emitter wavelength, turbidity of sea water, especially in coastal zones and undulation of the sea surface. The problem of developing a method for mapping the bottom relief of shallow-water reservoirs is formulated and solved. A laser installed on board the aircraft is used as an emitter. It is noted that one of the main problems in laser bathymetry is the issue of modeling the seabed. While the surface of various reservoirs is currently modeled by various continuous functions, such as Hermite polynomials, B-splines, etc., modeling of reflection from the bottom of a reservoir is mainly limited to a diffuse model, i.e. The bottom is considered as a Lambert reflector Based on the geometric representation of the course of optical rays in laser bathymetry and the analysis of known measurement results, a step model of the bottom of the reservoir is proposed, the height and width of the steps of which vary widely. Based on the wellknown method of mapping the bottom of a shallow reservoir from one point, as well as the proposed step model of the bottom of the reservoir, a method for mapping the relief of the bottom irregularity has been developed, according to which measurements are carried out at two spatial points, with respect to which the difference in the depth of the reservoir should be determined. At the same time, measurements are carried out using a laser beam of constant power and at constant nadir angles, model studies have shown that the measurement error of the proposed method is within ±4.5%.

The article describes the problem solution option to determine the size of the clear opening area for through-thickness damage in the underwater pipeline with encasement. The integrated method is proposed to determine damages like ruptures, bursts, kinks/breaks, etc., formed in the pipeline wall or in pipeline encasement joints. According to the proposed method, the main indicators that enable calculating the size of such damage – the distance to the point of damage occurrence and the pressure at the point of damage occurrence are determined separately – using fundamentally different methods. According to the method proposed, the distance to the point of through-thickness damage is determined by piezoelectric cells placed with a certain spacing in the pipeline – encasement annulus, and the pressure in the point of damage is estimated using classical design methods. The formula is obtained to calculate the size of the clear opening area for through-thickness damage according to the proposed integrated method.

The article is devoted on development of general concept for development of diagnostic-geodesy laser scanners useful for both the geodesy support of construction and exploitation of main gas pipelines. The carried out review of existing works on such an extension of functional capabilities of laser scanners in direction of combination of geodesy and diagnostic functions of laser at the stages of construction and exploitation of gas pipelines shown absence of any works in such direction. The possibility of technical realization of such extension of functions of laser scanner are considered. The general task on development of laser scanners operating in infrared band for construction and exploitation of gas pipelines is formulated. Optimization of functioning regime of laser scanner working in regime of detection of gas leaks in main gas pipelines is carried out. Synthesis of specialized laser scanner capable to realize functions of geodesy laser scanner during pipeline construction and functions of diagnostics that is detection of gas leaks in stage of pipeline exploitation is carried out. It is shown that technical realization of calculated optimum interrelation between main functional parameters of the system can be realized during serial measurements by organization of adaptive control of laser beam power depending on distance between measuring instrument and gas pipeline. At the same time the system should be equipped by laser distance meter included into gas leak detection system operating in adaptive regime.

It is noted that necessity of further increase of accuracy of GPS positioning systems requires de-velopment of more perfect methods to compensate information losses occurred due to residual ionospheric delay by using optimization procedures. According to the conditions of formulated optimization task, the signal/noise ratio in measurements of zenith wet delay depends on the second order ionospheric errors, geographic latitude and day of year. At the same time if we assume that the number of measurements at the fixed geographic site is proportional to geographic latitude and if we accept existence of only two antiphase scenarios for variation of residual ionospheric delay on latitude normed by their specific constant, there should be optimum functional dependence of precipitated water on latitude upon which the quantity of measuring information reaches the maximum. The mathematical grounding of solution of formulated optimization task is given.

The existing actual material on experimental assessment of positioning error in VRS GPS networks is analyzed where the mobile receiver is provided with virtual reference station. The method of highly informative zone is suggested for removal of initial uncertainty in reference station selection with the aim to develop minimal GPS network consisting of three reference stations. Methodical recommendations and directions are given for the suggested method application.

The Nernst-Ettingshausen effect is studied in thin conductive films in a strong transverse magnetic field. The expression is obtained for the NE coefficient Q for arbitrary charge carrier statistics and film thickness, assuming dimensional quantization and piezo-acoustic phonon scattering. It is shown that in the case of films with degenerate electron gas the NE coefficient oscillates with the variation of the thickness of the film d. The oscillation period is determined as a function of the concentration of the conduction electrons. Taking account of the surface scattering a detailed analysis of the NE coefficient dependence on the film thickness is given including films of thickness comparable to the mean free path of the charge carriers. Computer calculations show that under these conditions the function Q(d) is non-monotonous as well. [Russian Text Ignored]