Computing the trajectories for the development of optimal routes

Planning the construction of new transport routes or power lines on terrain is usually carried out manually by engineers, with no guarantee of optimality. We introduce a new approach for the computation of an optimal trajectory for the construction of new transit routes and power lines between two locations on a submanifold $$U\subset \mathbb {R}^{3}$$ U ⊂ R 3 representing the topography of a terrain. U is approximatively modeled by a special weighted grid. On this grid, the shortest paths for the construction of new routes are determined, whereby we consider three optimization criteria: routes with minimum distance, routes with lowest construction costs and routes with minimum absolute altitude variations or minimum absolute gradients. Subsequently, a combination of these criteria is used to expand this problem into a multi-criteria optimization problem. A shortest path algorithm, such as the Dijkstra algorithm, is used to compute optimal compromises for the construction of new routes.

Geographical distribution and ecological-phitocenotic features of orchids of the Southern Altai in the Kazakh Altai

According to the results of the study, 14 species of orchids were found in the flora of the southern Altai in2019, which is 52 % of the species diversity of the Orchid flora of Kazakhstan. It is established that the coenopopulationsof orchids in the region develop and exist within the boundaries of specific phytocenoses and are characterized by a certainecological and phytocenotic amplitude of the development of natural environment conditions. They are distributed in thelower, middle and upper mountain zones. The widest altitude range is typical for species from the genus Dactylorchiza(absolute altitude 462–1365 m). In terms of life forms, species with a stem-like tuberoid (genera Dactylorhiza, Herminium,Orchis) predominate, while short-rooted and long-rooted species (genera Cypripedium, Epipactis) are less represented. InKaton-Karagai district, 10 species of orchids were recorded growing in 19 cenopopulations, in Kurchum – 5 species in 6cenopopulations. Vegetation cover in habitats is formed from 35 to 90 %. Due to the weak competition of orchids, theirshare in the addition of phytocenoses does not exceed 2 %.

ON IMPROVEMENT OF PARACHUTE-RETROROCKET AIRDROP SYSTEM

The paper is devoted to the study of the prospects for improving the parachute-retrorocket airdrop system (PRS) in order to increase its reliability and enable the ability to adjust the orientation of a load in the horizontal plane depending on the slope of the earth's surface at the landing site. The primary task is to improve the accuracy of the altimeter, which determines the triggering moment of the PRS jet engines. The replacement of a mechanical altimeter of an outdated design with a modern electronic radio altimeter based on phased array radar is proposed, which allows to improve the accuracy of determining the absolute altitude(distance to the ground) and to take into account a roll of the load during the descent. The ways of determining the slope of earth's surface at the estimated landing site are also discussed. The results obtained make it possible to increase the accuracy of radio altimeter operation and significantly reduce the probability of an error in determining the absolute altitude due to rocking or static roll of the object. In addition to determining the current values of the height and speed of the descent of the vehicle, the use of a scanning radar makes it possible to estimate the inclination angle of the Earth’s surface at the landing site (in the radar scanning plane). If a certain angle of inclination of the earth surface at the landing site turns out to be too large, the probability of a successful landing can be increased by correcting the object's descent path, taking into account the information received. One of the easiest ways to correct a descent trajectory is to equip an object with small aerodynamic elements (rudders) and electromechanical actuators, ensuring their necessary orientation based on the results of determining the surface relief with radar. As one of the options, the authors propose the use of additional jet engines, which are structurally located on opposite sides of the object of landing in such a way as to form a torque of rotation of the object in a space from 0 ° to 90 ° in the horizontal plane due to the kinetic energy of motion from the actuation of jet engines. The triggering moment of the squibs is calculated based on determining the optimal distance of the object to the ground surface, and the need for triggering the squibs to rotate the object (correcting its position in space) depends on a certain value of the slope angle of the earth surface and comparing it with the admissible critical values of the angle, at which the object loses its stability during landing.

Quantitative model of hematologic and plasma volume responses after ascent and acclimation to moderate to high altitudes

Despite decades of research, the magnitude and time course of hematologic and plasma volume (PV) changes following rapid ascent and acclimation to various altitudes are not precisely described. To develop a quantitative model, we utilized a comprehensive database and general linear mixed models to analyze 1,055 hemoglobin ([Hb]) and hematocrit (Hct) measurements collected at sea level and repeated time points at various altitudes in 393 unacclimatized men ( n = 270) and women ( n = 123) who spent between 2 h and 7 days at 2,500–4,500 m under well-controlled and standardized experimental conditions. The PV change (ΔPV) was calculated from [Hb] and Hct measurements during a time period when erythrocyte volume is stable. The results are 1) ΔPV decreases rapidly (~6%) after the 1st day at 2,500 m and [Hb] and Hct values increase by 0.5 g/dl and 1.5 points, respectively; 2) ΔPV decreases an additional 1%, and [Hb] and Hct increase an additional 0.1 g/dl and 0.2 points every 500-m increase in elevation above 2,500 m after the 1st day; 3) ΔPV continues to decrease over time at altitude, but the magnitude of this decrease and subsequent increase in [Hb] and Hct levels is dependent on elevation and sex; and 4) individuals with high initial levels of [Hb] and Hct and older individuals hemoconcentrate less at higher elevations. This study provides the first quantitative delineation of ΔPV and hematological responses during the first week of exposure over a wide range of altitudes and demonstrates that absolute altitude and time at altitude, as well as initial hematologic status, sex, and age impact the response.

Altitude registration of limb-scattered radiation

One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh scattering attitude sensing (RSAS) and absolute radiance residual method (ARRM), are able to determine altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but, because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosol contamination. ARRM, a new technique introduced in this paper, can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of RSAS to Limb Profiler (LP) measurements from the Ozone Mapping and Profiler Suite (OMPS) on board the Suomi NPP (SNPP) satellite indicates tangent height (TH) errors greater than 1 km with an absolute accuracy of ±200 m. Results using ARRM indicate a ∼ 300 to 400 m intra-orbital TH change varying seasonally ±100 m, likely due to either errors in the spacecraft pointing or in the geopotential height (GPH) data that we use in our analysis. ARRM shows a change of ∼ 200 m over ∼ 5 years with a relative accuracy (a long-term accuracy) of ±100 m outside the polar regions.

Altitude Registration of Limb-Scattered Radiation

One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh Scattering Attitude Sensing (RSAS) and Absolute Radiance Residual Method (ARRM), have been developed to determine the altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances, and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosols. ARRM can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of these methods to Ozone Mapping and Profiler Suite (OMPS) Limb Profiler (LP) measurements showed that, at launch, the OMPS LP instrument had a 1–2 km altitude registration error, resulting in a 50 % error in the derived ozone density at some altitudes. Though some of the error has been attributed to thermal shifts in the focal plane of the instrument, most of it appears to be due to misalignment of the spacecraft star trackers or the OMPS LP focal plane with respect to the spacecraft axes. In addition, there are ±200 m seasonally varying errors that could either be due to errors in the spacecraft pointing information or in the geopotential height (GPH) data that we use in our analysis.