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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.