Modern methods of remote sensing of buildings and structures. Remote sensing

It is difficult to imagine the effective operation of modern GIS without satellite methods for studying the territories of our planet. Satellite remote sensing has found wide application in geo information technology both in connection with the rapid development and improvement of space technology, and with the curtailment of aviation and ground-based monitoring methods.

Remote sensing(DZ) is a scientific direction based on collecting information about the Earth’s surface without actual contact with it.

The process of obtaining surface data includes probing and recording information about the energy reflected or emitted by objects for the purpose of subsequent processing, analysis and practical use. The remote sensing process is presented in and consists of the following elements:

Rice. . Stages of remote sensing.

Availability of a source of energy or illumination (A) is the first requirement of remote sensing, i.e. there must be an energy source that illuminates or energizes the objects of interest for research with the energy of the electromagnetic field.

Radiation and Atmosphere (B) – Radiation that travels from a source to an object, part of the path passing through the Earth's atmosphere. This interaction must be taken into account, since the characteristics of the atmosphere influence the parameters of energy radiation.

Interaction with the object of study (C) - the nature of the interaction of radiation incident on the object strongly depends on the parameters of both the object and the radiation.

Energy registration by sensor (D) - radiation emitted by the object of study hits a remote, highly sensitive sensor, and then the received information is recorded on a medium.

Transmission, reception and processing of information (E) - information collected by the sensitive sensor is transmitted digitally to the receiving station, where the data is transformed into an image.

Interpretation and analysis (F) - the processed image is interpreted visually or using a computer, after which information regarding the object under study is extracted from it.

Application of the information received (G) - the process of remote sensing reaches completion when we obtain the necessary information regarding the object of observation for a better understanding of its characteristics and behavior, i.e. when some practical problem has been solved.

The following areas of application of satellite remote sensing (SRS) are distinguished:

Getting status information environment and land use; assessment of agricultural land yield;

Study of flora and fauna;

Assessment of the consequences of natural disasters (earthquakes, floods, fires, epidemics, volcanic eruptions);

Assessment of damage from land and water pollution;

Oceanology.

SDZ tools make it possible to obtain information about the state of the atmosphere not only on a local, but also on a global scale. Sounding data comes in the form of images, usually in digital form. Further processing is carried out by a computer. Therefore, the problems of SDZ are closely related to the problems of digital image processing.

To observe our planet from space, remote methods are used, in which the researcher has the opportunity to obtain information about the object being studied from a distance. Remote sensing methods, as a rule, are indirect, that is, they are used to measure not the parameters of interest to the observer, but some quantities associated with them. For example, we need to assess the condition of forests in the Ussuri taiga. The satellite equipment involved in monitoring will only record the intensity of the light flux from the objects being studied in several sections of the optical range. To decipher such data, preliminary research is required, including various experiments to study the state of individual trees using contact methods. Then it is necessary to determine what the same objects look like from an airplane, and only after that judge the condition of the forests using satellite data.

It is no coincidence that methods of studying the Earth from space are considered high-tech. This is due not only to the use of rocket technology, complex optical-electronic devices, computers, high-speed information networks, but also with a new approach to obtaining and interpreting measurement results. Satellite studies are carried out over a small area, but they make it possible to generalize data over vast spaces and even over the entire globe. Satellite methods, as a rule, allow obtaining results in a relatively short time interval. For example, for the vast Siberia, satellite methods are most suitable.

Features of remote methods include the influence of the environment (atmosphere) through which the signal from the satellite passes. For example, the presence of clouds covering objects makes them invisible in the optical range. But even in the absence of clouds, the atmosphere weakens radiation from objects. Therefore, satellite systems have to operate in so-called transparency windows, given that absorption and scattering by gases and aerosols take place there. In the radio range, it is possible to observe the Earth through clouds.

Information about the Earth and its objects comes from satellites in digital form. Terrestrial digital image processing is carried out using computers. Modern satellite methods allow not only to obtain images of the Earth. Using sensitive instruments, it is possible to measure the concentration of atmospheric gases, including those causing the greenhouse effect. The Meteor-3 satellite with the TOMS instrument installed on it made it possible to assess the state of the entire ozone layer of the Earth within a day. The NOAA satellite, in addition to obtaining surface images, makes it possible to study the ozone layer and study vertical profiles of atmospheric parameters (pressure, temperature, humidity).

Remote methods are divided into active and passive. Using active methods the satellite sends a signal from its own energy source (laser, radar transmitter) to Earth and registers its reflection, Fig. 3.4a. Passive methods involve recording solar energy reflected from the surface of objects or thermal radiation from the Earth.

Rice. . Active (a) and passive (b) remote sensing methods.

When remotely sensing the Earth from space, the optical range of electromagnetic waves and the microwave part of the radio range are used. The optical range includes the ultraviolet (UV) region of the spectrum; visible area - blue (B), green (G) and red (R) stripes; infrared (IR) - near (NIR), mid and thermal.

In passive sensing methods in the optical range, the sources of electromagnetic energy are solid, liquid, and gaseous bodies heated to a sufficiently high temperature.

At waves longer than 4 microns, the Earth's own thermal radiation exceeds that of the Sun. By recording the intensity of the Earth's thermal radiation from space, it is possible to accurately estimate the temperature of land and water surfaces, which is the most important environmental characteristic. By measuring the temperature of the cloud top, you can determine its height, taking into account that in the troposphere with height the temperature decreases by an average of 6.5 o / km. When registering thermal radiation from satellites, the wavelength range of 10-14 microns is used, in which absorption in the atmosphere is low. At a temperature of the earth's surface (clouds) equal to –50o, the maximum radiation occurs at 12 microns, at +50o – at 9 microns.

REMOTE SENSING
collection of information about an object or phenomenon using a recording device that is not in direct contact with this object or phenomenon. The term "remote sensing" usually includes the registration (recording) of electromagnetic radiation through various cameras, scanners, microwave receivers, radars and other such devices. Remote sensing is used to collect and record information about the seabed, the Earth's atmosphere, and the solar system. It is carried out using sea ​​vessels, airplanes, spacecraft and ground-based telescopes. Field-oriented sciences, such as geology, forestry and geography, also commonly use remote sensing to collect data for their research.
see also
COMMUNICATIONS SATELLITE;
ELECTROMAGNETIC RADIATION .

ENGINEERING AND TECHNOLOGY
Remote sensing covers theoretical research, laboratory works, field observations and data collection from aircraft and artificial Earth satellites. Theoretical, laboratory and field methods They are also important for obtaining information about the Solar system, and someday they will begin to be used to study other planetary systems in the Galaxy. Some of the most developed countries regularly launch artificial satellites to scan the Earth's surface and interplanetary space stations for deep space exploration.
see also
OBSERVATORY;
SOLAR SYSTEM ;
EXTRA-ATMOSPHERE ASTRONOMY;
SPACE EXPLORATION AND USE.
Remote sensing systems. This type of system has three main components: an imaging device, a data acquisition environment, and a sensing base. As simple example Such a system can be used by an amateur photographer (base), who uses a 35 mm camera (visualization device that forms an image), which is charged with highly sensitive photographic film (recording medium), to photograph a river. The photographer is at some distance from the river, but records information about it and then stores it on photographic film.
Imaging devices, recording medium and base. Imaging instruments fall into four main categories: still and film cameras, multispectral scanners, radiometers, and active radars. Modern single-lens reflex cameras create an image by focusing ultraviolet, visible or infrared radiation coming from a subject onto photographic film. After the film is developed, a permanent image (capable of being preserved for a long time) is obtained. The video camera allows you to receive an image on the screen; The permanent record in this case will be the corresponding recording on the videotape or a photograph taken from the screen. All other imaging systems use detectors or receivers that are sensitive at specific wavelengths in the spectrum. Photomultiplier tubes and semiconductor photodetectors, used in combination with optical-mechanical scanners, make it possible to record energy in the ultraviolet, visible, and near, mid, and far infrared regions of the spectrum and convert it into signals that can produce images on film. Microwave energy (microwave energy) is similarly transformed by radiometers or radars. Sonars use the energy of sound waves to produce images on photographic film.
see also
ULTRA HIGH FREQUENCY RANGE;
RADAR;
SONAR. The instruments used to render images are located on a variety of bases, including on the ground, ships, airplanes, balloons and spacecraft. Special cameras and television systems are used every day to photograph physical and biological objects of interest on land, sea, atmosphere and space. Special time-lapse cameras are used to record changes in the earth's surface such as coastal erosion, glacier movement and vegetation evolution.
Data archives. Photographs and images taken as part of aerospace imaging programs are properly processed and stored. In the US and Russia, archives for such information data are created by governments. One of the main archives of this kind in the United States, EROS (Earth Resources Obsevation Systems) Data Center, subordinate to the Department of the Interior, stores approx. 5 million aerial photographs and approx. 2 million images from Landsat satellites, as well as copies of all aerial photographs and satellite images of the Earth's surface held by the National Aeronautics and Space Administration (NASA). This information is open access. Various military and intelligence organizations have extensive photo archives and archives of other visual materials.
Image analysis. The most important part of remote sensing is image analysis. Such analysis can be performed visually, by computer-enhanced visual methods, and entirely by computer; the latter two involve digital data analysis. Initially, most remote sensing data analysis work was done by visually examining individual aerial photographs or by using a stereoscope and overlaying the photographs to create a stereo model. Photographs were usually black and white and color, sometimes black and white and color in infrared, or - in rare cases - multispectral. The main users of data obtained from aerial photography are geologists, geographers, foresters, agronomists and, of course, cartographers. The researcher analyzes the aerial photograph in the laboratory to directly extract useful information from it, then plot it on one of the base maps and determine the areas that will need to be visited during field work. After field work, the researcher re-evaluates the aerial photographs and uses the data obtained from them and from field surveys to create the final map. Using these methods, many different thematic maps are prepared for release: geological, land use and topographic maps, maps of forests, soils and crops. Geologists and other scientists conduct laboratory and field studies of the spectral characteristics of various natural and civilizational changes occurring on Earth. The ideas from such research have found application in the design of multispectral MSS scanners, which are used on aircraft and spacecraft. The Landsat 1, 2 and 4 artificial Earth satellites carried MSS with four spectral bands: from 0.5 to 0.6 μm (green); from 0.6 to 0.7 µm (red); from 0.7 to 0.8 µm (near IR); from 0.8 to 1.1 µm (IR). The Landsat 3 satellite also uses a band from 10.4 to 12.5 microns. Standard composite images using the artificial coloring method are obtained by combining MSS with the first, second and fourth bands in combination with blue, green and red filters, respectively. On the Landsat 4 satellite with the advanced MSS scanner, the thematic mapper provides images in seven spectral bands: three in the visible region, one in the near-IR region, two in the mid-IR region and one in the thermal IR region . Thanks to this instrument, the spatial resolution was improved almost threefold (to 30 m) compared to that provided by the Landsat satellite, which used only the MSS scanner. Since the sensitive satellite sensors were not designed for stereoscopic imaging, it was necessary to differentiate certain features and phenomena within one specific image using spectral differences. MSS scanners can distinguish between five broad categories of land surfaces: water, snow and ice, vegetation, outcrop and soil, and human-related features. A scientist who is familiar with the area under study can analyze an image obtained in a single broad spectral band, such as a black-and-white aerial photograph, which is typically obtained by recording radiation with wavelengths from 0.5 to 0.7 µm (green and red regions of the spectrum). However, as the number of new spectral bands increases, it becomes increasingly difficult for the human eye to distinguish between important features similar tones in different parts of the spectrum. For example, only one survey shot from the Landsat satellite using MSS in the 0.5-0.6 µm band contains approx. 7.5 million pixels (picture elements), each of which can have up to 128 shades of gray ranging from 0 (black) to 128 (white). When comparing two Landsat images of the same area, you're dealing with 60 million pixels; one image obtained from Landsat 4 and processed by the mapper contains about 227 million pixels. It clearly follows that computers must be used to analyze such images.
Digital image processing. Image analysis uses computers to compare the gray scale (range of discrete numbers) values ​​of each pixel in images taken on the same day or on several different days. Image analysis systems perform classification specific features shooting plan in order to compile a thematic map of the area. Modern image reproduction systems make it possible to reproduce on a color television monitor one or more spectral bands processed by a satellite with an MSS scanner. The movable cursor is placed on one of the pixels or on a matrix of pixels located within some specific feature, for example a body of water. The computer correlates all four MSS bands and classifies all other parts of the satellite image that have similar sets of digital numbers. The researcher can then color code areas of "water" on a color monitor to create a "map" showing all the bodies of water in the satellite image. This procedure, known as regulated classification, allows systematic classification of all parts of the analyzed image. It is possible to identify all major types of earth's surface. The computer classification schemes described are quite simple, but the world around us is complex. Water, for example, does not necessarily have a single spectral characteristic. Within the same shot, bodies of water can be clean or dirty, deep or shallow, partially covered with algae or frozen, and each of them has its own spectral reflectance (and therefore its own digital characteristic). The interactive digital image analysis system IDIMS uses a non-regulated classification scheme. IDIMS automatically places each pixel into one of several dozen classes. After computer classification, similar classes (for example, five or six water classes) can be collected into one. However, many areas of the earth's surface have rather complex spectra, which makes it difficult to unambiguously distinguish between them. An oak grove, for example, may appear in satellite images to be spectrally indistinguishable from a maple grove, although this problem is solved very simply on the ground. According to their spectral characteristics, oak and maple belong to broad-leaved species. Computer processing with image content identification algorithms can significantly improve the MSS image compared to the standard one.
APPLICATIONS
Remote sensing data serves as the main source of information in the preparation of land use and topographic maps. NOAA and GOES weather and geodetic satellites are used to monitor cloud changes and the development of cyclones, including hurricanes and typhoons. NOAA satellite imagery is also used to map seasonal changes in snow cover in the northern hemisphere for climate research and to study changes in sea currents, which can help reduce shipping times. Microwave instruments on the Nimbus satellites are used to map seasonal changes in ice cover in the Arctic and Antarctic seas.
see also
GOLFSTREAM ;
METEOROLOGY AND CLIMATOLOGY. Remote sensing data from aircraft and artificial satellites are increasingly being used to monitor natural grasslands. Aerial photographs are very useful in forestry because of the high resolution they can achieve, as well as the accurate measurement of plant cover and how it changes over time.

Yet it is in the geological sciences that remote sensing has received its widest application. Remote sensing data is used to compile geological maps indicating the types of rocks, as well as the structural and tectonic features of the area. In economic geology, remote sensing serves as a valuable tool for locating mineral deposits and geothermal energy sources. Engineering geology uses remote sensing data to select construction sites that meet specified requirements and determine the location of building materials, control over mining operations from the surface and land reclamation, as well as for carrying out engineering work in the coastal area. In addition, these data are used in assessments of seismic, volcanic, glaciological and other geological hazards, as well as in situations such as forest fires and industrial accidents.

Remote sensing data forms an important part of research in glaciology (relating to the characteristics of glaciers and snow cover), geomorphology (relief shapes and characteristics), marine geology (morphology of the sea and ocean floors), and geobotany (due to the dependence of vegetation on underlying mineral deposits) and in archaeological geology. In astrogeology, remote sensing data is of primary importance for the study of other planets and moons in the solar system, and in comparative planetology for the study of Earth's history. However, the most exciting aspect of remote sensing is that satellites placed in Earth orbit for the first time have given scientists the ability to observe, track and study our planet as a complete system, including its dynamic atmosphere and landforms as they change under the influence of natural factors and human activities. Images obtained from satellites may help find the key to predicting climate change, including those caused by natural and man-made factors. Although the United States and Russia have been conducting remote sensing since the 1960s, other countries are also contributing. The Japanese and European Space Agencies plan to launch a large number of satellites into low-Earth orbits designed to study the Earth's land, seas and atmosphere.
LITERATURE
Bursha M. Fundamentals of space geodesy. M., 1971-1975 Remote sensing in meteorology, oceanology and hydrology. M., 1984 Seibold E., Berger V. Ocean bottom. M., 1984 Mishev D. Remote sensing of the Earth from space. M., 1985

Collier's Encyclopedia. - Open Society. 2000 .

Benefits of Remote Sensing

Remote sensing is the process of obtaining information about objects without coming into physical contact with them. However, this definition is too broad.

Therefore, we will introduce some restrictions that allow us to specify the features of the concept of “remote sensing”, and in particular, the concept of remote sensing of the atmosphere, which is important for ensuring aviation safety. Firstly, it is assumed that information is obtained using technical means.

Secondly, we are talking about objects located at significant distances from technical means, which fundamentally distinguishes remote sensing from other scientific and technical areas, such as non-destructive testing of materials and products, medical diagnostics, etc. We add that remote sensing uses indirect methods measurements.

Remote sensing includes studies of the atmosphere and the earth's surface, and subsurface sensing methods have recently developed. The use of methods and means of remote non-contact obtaining information about the state and parameters of the troposphere contributes to aviation safety.

The main advantages of remote sensing are the high speed of obtaining data on large volumes of the atmosphere (or large areas of the earth's surface), as well as the ability to obtain information about objects that are practically inaccessible for research by other means. With traditional meteorological measurements in the upper atmosphere carried out using balloons, sophisticated remote sensing techniques have been widely and systematically applied.

Remote sensing is quite expensive, especially from space. Despite this, comparative analysis costs and results obtained proves high economic efficiency probing. In addition, the use of sensing data, particularly from weather satellites, ground-based and airborne radar, has saved thousands human lives by preventing natural disasters and avoiding dangerous meteorological phenomena. Therefore, research. experimental, design and operational activities in the field of remote sensing, which are intensively developing in the leading countries of the world, are fully justified.

Objects and applications of remote sensing

The main objects of remote sensing are:

weather and climate (precipitation, clouds, wind, turbulence, radiation);

environmental elements (aerosols, gases, atmospheric electricity, transfer, i.e. redistribution of a particular substance in the atmosphere);

oceans and seas (sea waves, currents, amount of water, ice);

earth's surface (vegetation, geological research, resource studies, altitude).

Information obtained by means of remote sensing is necessary for many branches of science, technology and economics. The number of potential consumers of this information is constantly growing.

In order to ensure flight safety, remote sensing is used:

meteorology, climatology and atmospheric physics (operational data for weather forecasting, determining the profile of temperature, pressure and water vapor content in the atmosphere, measuring wind speed, etc.);

satellite navigation, communications, radar observations and radio navigation (these areas require data on the conditions of radio wave propagation, which are quickly obtained by remote sensing means);

aviation, for example, forecasting weather conditions at airports and on air routes, prompt detection of dangerous meteorological phenomena such as hail, thunderstorm, turbulence, wind shear, micro-explosion and icing.

In addition, the following areas are important in which aircraft are used as carriers of remote sensing equipment:

hydrology, including assessment and management water resources, snow melt forecasting, flood warnings;

agricultural areas (weather forecast and control, control of the type, distribution and condition of vegetation, construction of soil type maps, determination of humidity, hail prevention, crop forecast);

ecology (control of air and land surface pollution);

oceanography (for example, measuring sea surface temperature, studying ocean currents and sea wave spectra);

glaciology (for example, mapping the distribution and movement of ice sheets and sea ​​ice, determining the possibility of maritime navigation in ice conditions);

geology, geomorphology and geodesy (e.g. identification of rock types, localization of geological defects and anomalies, measurement

Earth parameters and observation of tectonic movement);

topography and cartography (in particular, obtaining accurate data on height and linking them to a given coordinate system, producing maps and making changes to them);

natural disaster control (including monitoring the volume of floods, warning about sand and dust storms, avalanches, landslides, determining avalanche routes, etc.);

planning in other technical applications (eg land use inventory and change control, land resource assessment, traffic monitoring);

military applications (monitoring the movement of equipment and military units, terrain assessment).

Remote sensing systems and methods

The classification of remote sensing systems is based on the differences familiar to radar specialists between active and passive systems. Active systems irradiate the medium under study with electromagnetic radiation (EMR), which is provided by the sensing system, i.e. in this case, the sensing device generates electromagnetic energy and emits it in the direction of the object under study. Passive systems perceive EMR from the object under study in a natural way. This can be either its own EMR, arising in the sensing object itself, for example, thermal radiation, or scattered EMR from some natural external source, for example, solar radiation. The advantages and disadvantages of each of the two indicated types of remote sensing systems (active and passive) are determined by a number of factors. For example, a passive system is practically inapplicable in cases where there is no sufficiently intense intrinsic radiation of the objects under study in a given wavelength range. On the other hand, an active system becomes technically infeasible if the radiated power required to obtain a sufficient reflected signal is too high.

In some cases, to obtain the necessary information, it is desirable to know the exact parameters of the emitted signal in order to provide some special analysis capabilities, for example, measuring the Doppler frequency shift of the reflected signal to assess the movement of the target in relation to the sensor (receiver) or changes in the polarization of the reflected signal relative to the probing signal. Like any information-measuring systems that use EMR, remote sensing systems differ in frequency ranges of electromagnetic oscillations, for example, ultraviolet, visible light, infrared, millimeter, centimeter, decimeter.

Let's consider the remote sensing of the atmosphere, in particular, the troposphere - that part of the earth's atmosphere that is directly adjacent to the Earth's surface. The troposphere extends to altitudes of 10-15 km, and in tropical latitudes - up to 18 km. The use of remote sensing for the purpose of meteorological ensuring flight safety requires attention to systems that consider the atmosphere as a three-dimensional, volumetrically distributed object, and allow obtaining atmospheric profiles in different sensing directions.

Sensing objects, or targets, can be fluctuations that naturally occur in the atmosphere, as well as fixed objects at a certain distance from the remote sensing device. It is important to understand the essence of the different types of interaction between EMR and the atmosphere. Different types of such interaction are convenient way classification of remote sensing methods. They are based on the attenuation, scattering and emission of electromagnetic oscillations by sensing objects. Schemes of the main processes of interaction of electromagnetic oscillations with atmospheric inhomogeneities in relation to remote sensing problems.

In the first case, radiation from a given known source (transmitter) arrives at the input of the receiver after it has passed through the object under study. The amount of radiation attenuation along the propagation path from the transmitter to the receiver is estimated, and it is assumed that the amount of electromagnetic energy loss when passing through an object is related to the properties of this object. The cause of loss may be absorption or a combination of absorption and scattering, which is the basis for obtaining information about an object. Many remote sensing methods are essentially based on this approach.

In the second case, when the source itself is a source of radiation, the task usually arises of measuring infrared and/or microwave emission, which is used to obtain information about the thermal structure of the atmosphere and its other properties. In addition, this approach is typical for studying a lightning discharge based on its own radio emission and for detecting thunderstorms at long distances.

The third case is to use the scattering of electromagnetic oscillations by an atmospheric formation to obtain information about it. Based on the scattering property various ways DZ. One of them is characterized by the fact that the medium under study is illuminated by some source of incoherent radiation, for example, sunlight or infrared radiation that comes from the surface of the Earth, and the sensor of the remote sensing device receives the radiation scattered by the object. Another is that the object is irradiated by a special artificial (coherent or incoherent) source, for example, a laser or a source with a wavelength of decimeters to millimeters (as in the case of radar). This radiation is scattered by an object, detected by a receiver, and used to extract information about the scattering object.

Note that the first of the considered cases corresponds to an active sensing system, the second to a passive one, and the third is implemented in both passive and active versions.

An active remote sensing system can be mono-static, when the transmitter and receiver of the remote sensing device are located in one position, bistatic, or even multi-static, when the system consists of one or more transmitters and several receivers located in different positions.

The classification will not be complete enough if the main technical means Remote sensing: radars, radiometers, leaders and other devices or systems used as remote sensing sensors.

The study of the atmosphere using remote sensing includes the use of instruments installed on artificial Earth satellites and orbital stations, airplanes, rockets, balloons, as well as equipment located on the ground. Most often, remote sensing equipment is carried by satellites, aircraft and ground-based platforms.

Inverse problems

Remote control problems are inverse problems, i.e., those in the solution of which we are forced to go from the result to the cause. These include all tasks of processing and interpreting observational data. The theory of inverse problems is an independent mathematical discipline, and remote sensing of the atmosphere is only one of the scientific and technical areas for which the theory of inverse problems is important. In the applied aspect, it is necessary to have a good understanding of how EMR interacts with the atmospheric objects under study, generating signals that are used to obtain information about the atmosphere. In the ideal case, there is a one-to-one correspondence between the measured signal parameter and the estimated atmospheric characteristic. But in real situations, problems characteristic of inverse problems always arise.

Let's consider a simple example that relates to passive atmospheric sensing. Let us assume that the absorbing gas in the atmosphere is characterized by its own radiation, depending on the temperature of the gas. This radiation is detected by a sensor located on the satellite. Let us also assume that there is a connection between the wavelength of radiation and temperature, and temperature depends on the height of the atmospheric layer. Knowing the relationship between radiation intensity, radiation wavelength, and gas temperature then provides a way to estimate the temperature of the atmospheric gas as a function of wavelength and therefore altitude. In fact, the situation is much more complicated than the ideal case described. Radiation at a given wavelength does not come from a single layer at the corresponding height, but is distributed throughout the atmosphere, so there is no one-to-one correspondence between wavelength and height, as assumed for the ideal case, which causes this relationship to be blurred. This example is typical of many inverse problems, where the limits of integration depend on the features of a particular problem. This equation is known as the Fredholm integral equation of the first kind. It is characterized by the fact that the boundaries of the integral are fixed and appear only in the integrand. The function is called the kernel or kernel function of the equation.

Various remote sensing problems are reduced to an equation or similar equations. To solve such problems, it is necessary to perform an inverse transformation so that, based on the measurement results, g. receive distribution. Such inverse problems are called ill-posed or ill-posed problems. Their solution is associated with overcoming the following three difficulties. In principle, the solution to an ill-posed problem may turn out to be mathematically non-existent, ambiguous, or unstable. Lack of solution

From the remote sensing point of view, hazardous meteorological phenomena (HME) can be considered as volumetrically distributed objects that occupy certain spatial zones in cloudiness or in a cloudless atmosphere (clear sky). The physical signs of the external manifestation of an NME are, as a rule, described by parameters that characterize the intensity of an NME and which, in principle, can be measured, for example, parameters of wind speed, electric and magnetic field strength, and precipitation intensity. The physical parameters of the PMN are considered.

Regions of the atmosphere in which the parameters characterizing the intensity of the NME exceed a certain specified level are called NME zones. The process of detecting MN and assigning their zones to certain spatial coordinates at a given time based on remote sensing results is called localization of MN zones.

Thus, in the process of localization by means of microwave remote sensing of the atmosphere, EM zones are detected and their location in a given coordinate system is determined. In some cases, it is also possible to evaluate the degree of intensity of the AMN.

Localization of dangerous flight zones by airborne radar means is the rapid detection and determination of location using weather navigation radars (MNRS) and other drilling devices that can be interfaced with MNRLS.

6.1. Earth remote sensing concept

Remote sensing of the Earth (ERS) is understood as a non-contact study of the Earth, its surface, near-surface space and subsoil, individual objects, dynamic processes and phenomena by recording and analyzing their own or reflected electromagnetic radiation. Registration can be performed using technical means installed on aero- and spacecraft, as well as on the earth’s surface, for example, when studying the dynamics of erosion and landslide processes, etc.

Remote sensing, rapidly developing, has become an independent area of ​​using images. The relationship between the main directions of using images and the names of the directions can be represented by a diagram (Fig. 34).

Rice. 34. Diagram of the relationship between the main processes of obtaining and processing images

Currently most Earth remote sensing data is obtained from artificial Earth satellites (AES). Remote sensing data are aerospace images that are presented in digital form in the form of raster images, so the problems of processing and interpretation remote sensing data closely related to digital image processing.

Space image data has become available to a wide range of users and is actively used not only for scientific, but also for industrial purposes. Remote sensing is one of the main sources of current and operational data for geographic information systems (GIS). Scientific and technical achievements in the field of creation and development of space systems, technologies for obtaining, processing and interpreting data have greatly expanded the range of problems solved with the help of remote sensing. The main areas of application of remote sensing from space are studying the state of the environment, land use, studying plant communities, assessing crop yields, assessing the consequences of natural disasters, etc.

6.2. Applications of remote sensing data

The use of satellite images can be carried out to solve five problems.

1. Using the image as a simple map or, more precisely, a basis on which data from other sources can be applied in the absence of more accurate maps that reflect the current situation.

2. Determination of the spatial boundaries and structure of objects to determine their sizes and measure the corresponding areas.

3. Inventory of spatial objects in a certain territory.

4. Assessment of the condition of the territory.

5. Quantitative assessment of some properties of the earth's surface.

Remote sensing is a promising method for generating databases, the spatial, spectral and temporal resolution of which will be sufficient to solve problems of rational use natural resources. Remote sensing is an effective method for inventorying natural resources and monitoring their condition. Since remote sensing allows one to obtain information about any area of ​​the Earth, including the surface of seas and oceans, the scope of application of this method is truly limitless. The basis for the exploitation of natural resources is the analysis of information on land use and the state of land covers. In addition to collecting such information, remote sensing is also used to study natural disasters such as earthquakes, floods, landslides and subsidence.

Technologies for Earth remote sensing (ERS) from space is an indispensable tool for studying and constantly monitoring our planet, helping to effectively use and manage its resources. Modern technologies Remote sensing is used in almost all areas of our lives.

Today, technologies and methods for using remote sensing data developed by Roscosmos enterprises make it possible to offer unique solutions for ensuring safety, increasing the efficiency of exploration and production of natural resources, introducing the latest practices in agriculture, preventing emergency situations and eliminating their consequences, protecting the environment and controlling climate change.

Images transmitted by remote sensing satellites are used in many industries - agriculture, geological and hydrological research, forestry, environmental protection, land planning, education, intelligence and military purposes. Space remote sensing systems make it possible to obtain the necessary data from large areas(including hard-to-reach and dangerous areas).

In 2013, Roscosmos joined the activities of the International Charter on Space and Major Disasters. To ensure its participation in the activities of the International Charter, a specialized Roscosmos Center for interaction with the Charter and the Russian Ministry of Emergency Situations was created.

The head organization of the Roscosmos State Corporation for organizing the reception, processing and dissemination of Earth remote sensing information is the Scientific Center for Operational Earth Monitoring (SC OMZ) of the Russian Space Systems holding (part of the Roscosmos State Corporation). NC OMZ performs the functions of a ground-based complex for planning, receiving, processing and distributing space information from Russian spacecraft Remote sensing.

Areas of application of Earth remote sensing data

• Updating topographic maps
• Updating navigation, road and other special maps
• Forecast and control of flood development, damage assessment
• Monitoring Agriculture
• Control of hydraulic structures at reservoir cascades
• Real location of sea vessels
• Tracking the dynamics and state of forest felling
• Environmental monitoring
• Forest fire damage assessment
• Compliance with licensing agreements during the development of mineral deposits
• Monitoring oil spills and oil slick movement
• Ice monitoring
• Control of unauthorized construction
• Weather forecasts and monitoring of natural hazards
• Monitoring of emergency situations associated with natural and man-made impacts
• Emergency response planning in areas of natural and man-made disasters
• Monitoring of ecosystems and anthropogenic objects (expansion of cities, industrial zones, transport highways, drying up reservoirs, etc.)
• Monitoring the construction of road transport infrastructure facilities

Regulations, defining the procedure for obtaining and using geospatial information

• « Concept for the development of the Russian space system for remote sensing of the Earth for the period until 2025»
• Decree of the Government of the Russian Federation No. 370 of June 10, 2005, as amended on February 28, 2015 No. 182 “ On approval of the Regulations on the planning of space surveys, reception, processing and dissemination of high linear resolution Earth remote sensing data on the ground from spacecraft of the "Resurs-DK" type»
• Decree of the Government of the Russian Federation No. 326 of May 28, 2007 “ On the procedure for obtaining, using and providing geospatial information»
• Order of the President of the Russian Federation No. Pr-619GS dated April 13, 2007 and Order of the Government of the Russian Federation No. SI-IP-1951 dated April 24, 2007. " On the development and implementation of a set of measures to create in the Russian Federation a system of federal, regional and other operators of services provided using remote sensing data from space»
• The plan for the implementation of these instructions, approved by the Head of Roscosmos on May 11, 2007 “ On the implementation of a set of measures to create in the Russian Federation a system of federal, regional and other operators of services provided using remote sensing data from space»
• Government program Russian Federation « Russian space activities for 2013 - 2020» approved by Decree of the Government of the Russian Federation dated April 15, 2014 No. 306
• Basics public policy of the Russian Federation in the field of space activities for the period until 2030 and beyond, approved by the President of the Russian Federation dated April 19, 2013 No. Pr-906
• Federal Law of July 27, 2006 N 149-FZ “On information, information technologies and information protection» with amendments and additions from: July 27, 2010, April 6, July 21, 2011, July 28, 2012, April 5, June 7, July 2, December 28, 2013, May 5, 2014

Federal, regional and local authorities To the executive branch, in order to meet state needs, satellite imagery materials of the first level of standard processing (space images that have undergone radiometric and geometric correction) are provided free of charge. If it is necessary for the specified bodies to obtain satellite imagery materials of higher levels of standard processing, a fee for their production services is charged in accordance with the approved price list.