Issledovanie Zemli iz Kosmosa

In this work, the dynamics of changes and trends in climatic conditions, the vegetation index NDVI, the humidity of the upper soil layer and the content of black carbon in the atmosphere in the conditions of steppe fires by ground and satellite measurements for the period 2000–2022 are traced for the “Burtinskaya Steppe” in the Orenburg region. The negative trend in the values of the Selyaninov hydrothermal coefficient (HTC) indicates a tendency to weaken the moisture supply of the territory, which contributes to the occurrence of steppe fires. The consequence of climatic trends is a positive trend in the values of black carbon in the atmosphere of the studied area, as well as a tendency to decrease the biomass and humidity of the upper soil layer. Absolute interannual values were marked in 2010: minimum values of NDVI, soil moisture and maximum values of black carbon.

The paper presents the results of monitoring natural forest regrowth on abandoned agricultural land in the Middle Volga Region using remote sensing methods. The Mari El Republic was chosen as the test site for this research. The use of modern remote sensing methods makes it possible to identify and evaluate areas of natural forest regrowth on abandoned agricultural lands with higher accuracy and at lower financial and labour costs. Minimum noise fraction transformed images (Landsat-8 OLI-8) were used in a combination of sixth (mid-infrared), fifth (near-infrared) and second (blue) spectral channels for the research. The findings revealed that there is a steady process of mass forest regrowth on abandoned agricultural land in Mari El. The total area of agricultural land used in the research was 763.69 thousand hectares. Reforestation with deciduous species is observed on a territory of 135.5 thousand hectares, which makes up 17.7% of the total area of agricultural land and 49.9% of the territory of fallow land in the Republic of Mari El. Reforestation with coniferous species is observed on 26.7 thousand hectares, which amounts to 3.5% and 9.85%, respectively. Future studies can address anthropogenic and natural impacts on the structure and dynamics of new forest stands. A comprehensive analysis of the density of forest regrowth on abandoned agricultural lands should be carried out using existing maps of agricultural land, population density, and other socio-economic factors.

For the first time, for the SW part of the Malouralskaya zone of the Polar Urals, an approach was applied. The testing of which was obtained as a result of combining (1) methods of mathematical processing of information and (2) a set of data obtained by the Earth remote sensing spacecraft Harmonized Landsat Sentinel-2. The first one is based on the analysis of search features and their functional and correlation relationships. The second is the integration of maps of the distribution of hydrothermal alterations and the lineament density scheme, created on the basis of the results of statistical processing of remote sensing data. As a result of the study, two new areas were delineated and new predictive and prospecting features of gold mineralization were identified within the study area. (1) Areas promising for the gold mineralization type in the SW part of the Malouralskaya zone are localized along transregional fault zones that intersect favorable horizons and structures and control ore mineralization, and within the volcanic-tectonic structure (large morphostructure 40 × 45 km) of the 1st order. Within this depression, the accepted systems of modern volcanic structures of the 2nd and higher order, the position of which is controlled by junctions of NE- and NW-trending faults with a length of more than 10 km. (2) Potentially ore-bearing volcanic edifices show subsidence calderas and large area of metasomatic aureoles (more than 30 km²) with elevated indices of hydroxyl-(Al-OH, Mg-OH) and carbonate-bearing minerals and iron oxides and hydroxides (limonite) and, to a lesser extent, ferrous oxides.

The total ozone content (TOC) measurements results by the ground-based MR-32 instrument in 2015–2022 at the Obninsk station (55.11N; 36.60E) are presented. Solar radiation was measured by the FTIR spectrometer of medium resolution of 0.12 cm⁻¹. Based on the analysis of the absorption spectra the relevant spectral intervals in the region of 4.7 microns were determined. The SFIT4 program was applied to retrieve total ozone content. A comparison of the results of TOC measurements by the MR-32 instrument with satellite data of OMPS, OMI, and SBUV(MOD) showed good agreement. The correlation coefficients are 0.93–0.97. According to spectral and cross-correlation wavelet analysis, ground and satellite oscillations with periods from 4 to 60 months occur of almost synchronously. The systematic discrepancies between daily average ground-based and satellite TO measurements are (−0.8 ± 3.6)%, (−0.2 ± 3.7)% and (−2 ± 5)% for OMPS, OMI and SBUV(MOD), respectively.

The in-flight experiment “Reper-Kalibr” was conducted on board the International Space Station, in which the fixed points referenced to melt transition temperatures of the gallium eutectic alloys Ga-In (~288,8 К), Ga-Sn (~293,6 К), Ga-Zn (~298,3 К) and the Ga (~302,9 K) were investigated. Investigation of zero-gravity impact on the low-temperature fixed points characteristics is required to develop an on-orbit calibration scale within the range ~(210–350) K for creating in the end high-stable on-board fixed-point blackbodies designed for the space-based IR instruments in-flight calibration. The main experimental results are the series of melt plateaus in cycles of melt – freeze of the selected substances. The experiment has shown that the selected fixed points are useful for achieving said object. The comparative analysis of the results of ground-based and in-flight stages of the experiment is performed.

In this paper, we present a description of the method for adjusting the georeference of the “high-frequency” channels of the microwave sounder MTVZA-GYa. Analysis of radiometric measurements at a frequency of 91.65 GHz showed that the lack of horizontal polarization does not allow the use of the generally accepted georeferencing technique. Therefore, an alternative approach/method has been proposed for a group of 52–91 GHz channels that share a common horn. The method is based on the analysis of the features of the spatial distribution of the scattering index, which is an auxiliary function in the problem of restoring precipitation zones from radio polarimetric satellite measurements. The values selected based on the proposed method were: roll (−0.37 ± 0.71)°, pitch (0.21 ± 0.65)° and yaw (−1.21 ± 0.76)°. The accuracy of georeferencing using the indicated angles was 7.62 km. The inclusion of the proposed approach in the procedure for automatically determining the orientation angles of a group of frequency channels 52–91 GHz will help improve the accuracy of their geographic location, as well as the accuracy of solving remote sensing problems using them.