Aerospace Imagery Research Articles

THE ROLE OF REMOTE SENSING OF THE EARTH IN PRECISION AGRICULTURE

The paper provides a historical assessment of the increasing role of remote sensing data, the methods, services and tools used in their acquisition and applied in the information support of precision agriculture technologies. The main problems constraining the scalability of aerospace imagery application in precision crop production have been considered. The necessity to create a new research methodology, the formation of an appropriate physical, technical and experimental infrastructure to overcome them has been emphasized. The application of methodology for planning and conducting specialized experiments in conjunction with remote and ground-based monitoring of field experiments with test plots for detection within-field heterogeneity and the degree of its intensity has been depicted. For this purpose, has been created the functional that implements the capabilities of two new methods for within-field variability delineation and border marking based on aerospace images. The first one based on the main geostatistical tool – variogram analysis, and the other one is based on the systematic quantitative assessment of the dynamics of changes in the integral optical characteristics of the crop.

Влияние детальности аэрокосмических изображений на результаты классификации растительных сообществ тундры

Влияние детальности аэрокосмических изображений на результаты классификации растительных сообществ тундры

Assessment of ecological-geomorphological strength and risk of geosystems of the north-eastern slope of the Great Caucasus (within Azerbaijan)

Problem statement. The increased human pressure on natural geo-complexes is causing the revival of undesirable processes that create an extensive risk for the inhabitants of these regions. Alpine-type orogenic zones, which belong to the northeastern slope of the Greater Caucasus, are distinguished from many geomorphological systems by excessive activity of endo- and exogenous processes. Therefore, at this time, the task of diagnosing and assessing the ecological and geomorphological risk that the population faces in the development of new territories of the region seems to be important. Analysis of recent research and publications. After analyzing a number of techniques used to assess the landslide and mudflow hazards, the conclusion was made that most of them had their flaws. Research method. There are a large number of methods for assessing the risk of environmental management and predicting hazardous exodynamic processes. However, in modern conditions, these techniques are not sufficiently reliable. This, in turn, determines the relevance and the need to develop new or modernised methods of strategies for the prevention, protection, and elimination of the consequences of catastrophes and natural disasters. The purpose of this work is to reveal the geomorphological features and dynamics of the development of the most dangerous and often repeating landslide and mudflow processes based on field geomorphological studies, as well as fund literature, indicate the reasons for their formation and propose measures to combat them. Research results. The article discusses the results of ecological and geomorphological surveys on the northeastern slope of the Greater Caucasus, dedicated to the assessment of landslide and mudflow risk for the period from 1990 to 2020. To assess them in order to obtain morphometric characteristics (including the down gradient of slopes, the length and shape of slopes, areas of mudflow centers), large-scale (M 1:100000) topographic maps were used, as well as interpretation materials for different-scale and multi-temporal ASP. Based on the interpretation of the ASP within the studied region, in order to clarify the general picture of the dissection of the modern relief of the studied region, a map of morphometric tension was compiled, which includes the degree of vertical dissection of the territory, the down gradient of slopes, etc., and also maps of the risk of landslides and mudflows were compiled according to the degree of danger of landslide and mudflow processes, and the area of their distribution was calculated. Landslide and mudflow risk analysis mainly used high-resolution aerospace imagery (ASI) from CNES / Airbus, Maxar Technologies (GeoEye-1), and medium resolution Sentinel-2A and 2B. Thus visual and semi-automatic interpretation (classification with training) was performed in the ArcGIS environment. As a result, taking into account the morphometric tension, as well as the mudflow and landslide hazards, a map of the morphodynamic tension of the northeastern slope of the Greater Caucasus was compiled, which makes it possible to reveal the modern nature of the manifestation of exodynamic processes, to predict and assess the risk coming from them. Conclusion. The results of the research will make it possible to use the obtained data for the development of the Program for the safe and sustainable functioning and development for the purpose of recreational and tourist development of the difficult of access mountain geosystems of Azerbaijan.

ASSESSMENT OF NATURAL CONDITIONS FOR THE CONSTRUCTION OF LANDFALL OF TRANSITION OF THE BOVANENKOVO-UKHTA GAS PIPELINE THROUGH THE BAIDARATSKAYA GUBA (KARA SEA) ACCORDING TO REMOTE SENSING DATA

The results of multi-temporal aerospace imagery of the coast of the Baydaratskaya Bay (Kara Sea) interpretation are presented. In order to draw up a sketch map for the estimated zoning of the territory according to the construction conditions of the onshore sections of the Bovanenkovo-Ukhta gas pipeline, studies were carried out. The methods, consisting of 3 stages, was used: 1) sequential of aerial photographs and satellite images interpretation of different scales; 2) spatial comparison of the obtained interpretation results with the available cartographic materials of geotechnical surveys; 3) drawing up maps and sketch maps of various contents, including the final sketch map of the estimated zoning according to the degree of favorableness of the territory for the construction of gas pipelines. Landsat satellite images (1999–2000) with a resolution of 30 m, as well as aerial photographs of 1949–1950, scale 1:60 000, covering the southern part of the coast of the Baydaratskaya Bay were used for interpretation. The retreat of the gulf coasts, changes in the configuration of the coastline, river channels in their deltaic parts, changes in the size of thermokarst lakes have been discovered over the past 50 years in the course of analysis and interpretation of Earth remote sensing data. The amount of coastal retreat varies in different parts of the coast of the Baydaratskaya Bay from 30 to 90 m, i.e. the rate of retreat of the coastline is between 0.6 and 1.8 m / year has been established. The places of development of thermokarst and polygonal wedge ice, as well as active river erosion, have been identified by deciphering signs. At the third, final stage of the studies performed, based on the analysis of natural factors that determine the patterns of distribution of the studied hazardous processes and phenomena, a schematic assessment zoning of the studied territory was carried out according to the degree of its favorableness for the construction of onshore sections of the gas pipeline. Three types of areas: unfavorable, relatively unfavorable and favorable are noted on the sketch map

АНАЛИЗ МЕТОДИК СОЗДАНИЯ МАКЕТНЫХ СНИМКОВ ДЛЯ ПРОВЕРКИ ТОЧНОСТИ ФОТОГРАММЕТРИЧЕСКИХ ПОСТРОЕНИЙ

Digital photogrammetry is based on the use of specialized photogrammetric software (or digital photogrammetric systems) to solve problems related to the aerospace imagery processing. A wide range of programs and high price motivate consumers to choose the right software that responds to requirements of processing accuracy, amount of work, time of execution, etc. The main goal of this study is to analyze the existing methods of benchmark images creating to test photogrammetric pro-grams. The article carries out the analysis of existing techniques of creating benchmark images, classi-fication, selection of benchmark images types suitable for testing of photogrammetric software, and substantiates the necessity for checking of aerial survey results quality in specialized software.

Оценивание состояния растительности на основе аппарата нечёткой логики

Assessment of forest vegetation is based on multispectral space imagery processing. The issues of the formation of initial data and selection of test sites for automated identification of landscape elements are considered. The aim of the work is to present an assessment technology for natural objects that applies the mathematical apparatus of fuzzy logic to automated processing of multispectral aerospace imagery. An example of assessing the forest state and determining the consequences of a forest fi re is presented.

USE OF REMOTE GEOINFORMATION TECHNOLOGIES FOR FOREST PATHOLOGY MONITORING IN THE ZHYTOMYR POLISSYA

USE OF REMOTE GEOINFORMATION TECHNOLOGIES FOR FOREST PATHOLOGY MONITORING IN THE ZHYTOMYR POLISSYA

Hough Transform Application to Digitize Rectangular Spatial Objects on Aerospace Imagery

The paper describes the method of development for the remote sensing data processing to speed up the digitizing workflow. The method is designed to digitize rectangular objects using their approximate spatial positions and provides an automatic estimation of the orientation and aspect ratio. 
 The paper contains a formal statement of the problem of digitizing an object with the desired geometric shape using it’s apriori known spatial position on a source image. The method creates polygonal representations of rectangular spatial objects from one or a few reference points set by an operator. It is based on source image’s pixels clustering using spectral bands as a feature space. The following Hough transform incorporates local direction of intensity gradient to estimate object’s orientation and reduce computational complexity together with low-pass filtering within an accumulation process to improve robustness. It is shown that the developed method can be modified to digitize objects of any analytically described shape. 
 The method is designed to allow easy user interaction without any significant delays and to provide transparent and predictable control of an output object’s polygon size.
 To investigate the developed method a test dataset with more than 700 rectangular objects was used. The root-mean-square error of object’s points positioning, mean rotation error in polar coordinates and a Jaccard index were used to measure a precision of the digitized objects. The experiment results demonstrate that digitizing workflow is accelerated by 25–40% using the software implementing the developed method without a significant precision loss.

Spectral features for identification of the typical contaminations of sea water from aerospace imagery

Features of the spectral characteristics of clear and contaminated water bodies revealed in theoretical and experimental researches are considered. An original system of stable spectral features is formed and can be used to identify and estimate qualitative and quantitative characteristics of pollution of sea by oil products and mineral suspensions.

Methods for retrieval of sea wave spectra from aerospace image spectra

An approach to the retrieval of sea wave spatial spectra based on satellite optical imagery in linear and nonlinear approximations is described. Physical mechanisms of the formation of disturbed sea surface brightness fields recorded by remote sensing equipment are analyzed. Wave spectra retrieval methods using brightness field formation models that consider linear and nonlinear dependencies on sea surface slopes are suggested. A method for the construction of operators that retrieve the spatial spectra of surface wave slopes and elevations from aerospace imagery and take into account nonlinear modulations of disturbed sea surface brightness fields is developed. This method is based on the numerical simulation of sea surface images and the construction of a retrieving operator with respect to a set of parameters determined by aerospace imaging conditions. Examples of the use of the developed methods are given.

Retrieving sea-wave spectra using satellite-imagery spectra in a wide range of frequencies

A method to register sea-wave spectra using optical aerospace imagery has been developed. The method is based on the use of retrieval operators both in areas of high and low spatial frequencies, including the areas of spectral maximum. The approach to adjust and validate the method developed using sea truth data obtained by string wave recorders has been suggested. This paper presents the results of using the suggested method to study sea-wave spectra using high-resolution satellite imagery for various water areas under different conditions of wave generation.

Оптимизация состава спектральных каналов гиперспектральных аэрокосмических изображений при решении тематических задач дистанционного зондирования Земли

Оптимизация состава спектральных каналов гиперспектральных аэрокосмических изображений при решении тематических задач дистанционного зондирования Земли