The article is devoted to the problem of determining the location of an object in space within the framework of various tasks of monitoring the state of the environment, in conditions of inaccessibility of traditional satellite positioning. As part of the task of monitoring the state of the environment, monitoring agricultural territories and observing the atmosphere, the use of traditional satellite navigation systems in many cases is not available. To solve it, it is proposed to use passive methods for determining the location of the object. To increase their reliability in solving environmental monitoring problems, a new algorithm was developed for the difference-ranging method by increasing the number of used differences of arrival times. The difference between the signal arrival times may be less than 0.02 us. Using the algorithm allowed to abandon the use of the reference station and move on to differences in arrival times between all pairs of stations. In this case, the accuracy of determining the position of the object increases by 20 - 45%. The error in determining the position of the object does not exceed 1 m. This value allows the operational search of weather balloons and other equipment for environmental monitoring.
The article of the methods for coordinates determination of the object coordinates are reviewed. The advantages of a passive method with the using of the direction finder are noted. The problems arising from the transmission of signals in the direction finder method are determined. The construction for the signal transmission of the fiber optic communication line is presented. It is established that the greatest influence on the error in determining the coordinates of the object by direction finder has a phase shift in the optical fiber during a change the temperature. The chart of the phase shift at the temperature for various cases of optical fiber placement are investigated. The obtained data of the experimental investigations are presented.
An important task in developing new materials is the study of their structure (substructure). The present study uses a number of complementary methods to determine the size, morphology, phase composition and volume fraction of dispersed precipitates in high-strength medium-carbon steel tempered in the temperature range of up to 600°C. The methods of small-angle neutron scattering, X-ray and neutron diffraction were used. Such an advantage of neutrons as the ability to use large samples, which significantly increases the maximum permissible grain size to obtain statistically reliable results and takes into account texture data, explains the use of neutron sources along with the X-ray ones. The disadvantages include a lower resolution and more complex equipment. The combined use of different techniques made it possible to determine the kinetics of structural changes in the dispersed particles during tempering of steel. The increase in tempering temperature up to 300°C results in a decrease in the amount of retained austenite. At the tempering temperature of 300°C, the growth of Fe 3 C particles instead of retained austenite starts and continues up to 600°C up to which the studies were done. The phases of retained austenite and cementite were identified by means of neutron diffraction, while changes in sizes were determined by means of small-angle neutron scattering. The results obtained do not contradict the previous transmission electron microscopy data. A comprehensive study by means of diffraction and scattering methods of X-rays and neutrons allows one to obtain exhaustive information about disperse particles in steels.
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