scholarly journals Determination of the Spatial Resolution of Radar Images in Remote Sensing of the Earth

2021 ◽  
Vol 24 (3) ◽  
pp. 72-80
Author(s):  
S. N. Gusev ◽  
S. V. Zhuravlev ◽  
A. V. Popov
Keyword(s):  
Spatial Resolution ◽  
A Priori ◽  
Analytical Data ◽  
Radar Signal ◽  
Radar Images ◽  
Radar Systems ◽  
Current State ◽  
A Priori Estimation

Introduction. The analysis of the current state and prospects of space-based radar surveillance tools is important for determining their functions in global aerospace information systems, which aim to monitor air and space, as well as the Earth's surface. Radar surveillance information is used for the purposes of economic analysis, environmental monitoring, mineral search, emergency monitoring, detection and recognition of specified object s at sea and on land, as well as for ensuring national security. In this regard, it is of relevance to develop methods for preliminary assessment of the resolution capacity of novel high-precision onboard radar systems installed on a spacecraft, considering their main technical characteristics, the parameters of the spacecraft movement and the influence of the atmosphere. A priori estimation of spatial resolution values requires a method for calculating the corresponding indicators meeting the required quality of the synthesized radio holograms.Aim. To derive mathematical dependencies and logical rules allowing a priori estimation of the spatial resolution of radar images obtained by the onboard equipment of a radar complex.Materials and methods. Analytical methods were used to determine the resolution error of onboard radar systems with a synthesized aperture in the lateral (azimuthal) direction and range, as well as the theory of radar signal processing.Results. A comparison of the experimental and analytical data on the resolution capacity of an actual radar system confirmed the validity on the proposed method. The developed methodology was used to determine the procedure of calculating the error when estimating the resolution capacity in terms of azimuth and range. Conclusion. The proposed method can be used for both designing novel radar systems and comparing existing radar complexes, depending on the resolution requirements.

Experimental assessment of the information content of long-range portraits of radar objects

2021 ◽  
Author(s):  
V.E. Turov ◽  
A.V. Zyuzin ◽  
A.V. Timoshenko ◽  
V.P. Grutsya
Keyword(s):  
Experimental Data ◽  
Information Content ◽  
Long Range ◽  
A Priori ◽  
Complex Signals ◽  
Technical Literature ◽  
Radar Systems ◽  
Priori Information

At present, the scientific and technical literature discusses in detail the issues of obtaining information about the geometric characteristics of airborne radar targets (RC), which can be used as recognition signs. However, these issues and the methods being developed are considered in relation to single-position radar stations (radars) using simple or complex signals. Purpose of the work is determination of the informative value of the parameters of the long-range portraits of the RLS obtained by the method of statistical and physical modeling based on the processing of experimental data. A method is proposed for assessing the informativeness of long-range portraits of radar objects obtained as a result of processing reflected signals by various methods, including using weight processing based on a priori information about the structure of probing signals. Based on the analysis of the experimental data, it was found that the weight processing of the long-range portraits of the RLS provides an increase in the contrast of the portraits (an increase in the steepness of the portrait peaks and the depth of the dips), which, in turn, leads to an increase in the information content of each element of the long-range portrait and the totality of the features of the long-range portrait as a whole when recognizing RLO. The use of the technique allows us to assess the quality of the long-range portraits of the radar, obtained by various methods of processing radar signals and develop algorithms that increase the information content of radar systems with the recognition mode both for air and space radar and for objects against the background of the underlying surface during remote sensing.

scholarly journals Evaluation of a class of NLFM radar signals

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Sebastian Alphonse ◽  
Geoffrey A. Williamson
Keyword(s):  
Search Space ◽  
Frequency Function ◽  
Radar Signal ◽  
Optimized Design ◽  
Nonlinear Frequency ◽  
Signal Design ◽  
Signal Model ◽  
Radar Systems ◽  
Comprehensive Comparison

AbstractSignal design is an important component for good performance of radar systems. Here, the problem of determining a good radar signal with the objective of minimizing autocorrelation sidelobes is addressed, and the first comprehensive comparison of a range of signals proposed in the literature is conducted. The search is restricted to a set of nonlinear, frequency-modulated signals whose frequency function is monotonically nondecreasing and antisymmetric about the temporal midpoint. This set includes many signals designed for smaller sidelobes including our proposed odd polynomial frequency signal (OPFS) model and antisymmetric time exponentiated frequency modulated (ATEFM) signal model. The signal design is optimized based on autocorrelation sidelobe levels with constraints on the autocorrelation mainlobe width and leakage of energy outside the allowed bandwidth, and we compare our optimized design with the best signal found from parameterized signal model classes in the literature. The quality of the overall best such signal is assessed through comparison to performance of a large number of randomly generated signals from within the search space. From this analysis, it is found that the OPFS model proposed in this paper outperforms all other contenders for most combinations of the objective functions and is expected to be better than nearly all signals within the entire search set.

scholarly journals DATABASE DEVELOPMENT OF THE MANAGEMENT INNOVATIVE ACTIVITY IN THE INDUSTRIAL ENTERPRISE

2018 ◽  
Vol 2018 (1) ◽  
pp. 21-27
Author(s):  
Алексей Курлов ◽  
Aleksey Kurlov ◽  
Андрей Гулевитский ◽  
Andrey Gulevitsky
Keyword(s):  
System Analysis ◽  
Innovation Management ◽  
A Priori ◽  
Industrial Enterprise ◽  
Information Support ◽  
Industrial Enterprises ◽  
Preparatory Stage ◽  
Implementation Of Innovations

This article focuses on the decision of problems of increase of efficiency of introduction of innovation in industrial enterprise. The publication includes a description of the author's approach to innovation in the industrial enterprise, implemented in the form of a database. The main functions of the database are divided into two main stages – preparatory and informative. The functions of the preparatory stage include the collection of information about the industrial enterprise, the rationale for the choice of innovation, determination of the composition and administration of training (retraining), justification of the technical appearance of innovation. At the supporting stage, the database allows information support in the development and implementation of innovations in terms of timing, volume and costs, to carry out a priori and a posteriori evaluation of the quality of innovation on the basis of situational norms, as well as support for decision-making on innovation management in the industrial enterprise. The database is based on the theory of system analysis, the basic principles of the theory of innovation, methods of situational modeling, graph theory and probability theory. The results of the developed database can be used by modern industrial enterprises in the implementation of innovations.

scholarly journals ORGANIZATION OF MONITORING OF QUALITY OF INNOVATION PROCESSES IN ENTERPRISES OF ELECTRONIC INDUSTRY

2019 ◽  
Vol 1 (7) ◽  
pp. 110-116 ◽  
Author(s):  
A. Yu. Gulevitskij ◽  
A. V. Kurlov ◽  
V. V. Kurlov
Keyword(s):  
System Analysis ◽  
Innovation Management ◽  
A Priori ◽  
Industrial Enterprise ◽  
Information Support ◽  
Industrial Enterprises ◽  
Preparatory Stage ◽  
Implementation Of Innovations

This article focuses on the decision of problems of increase of efficiency of introduction of innovation in industrial enterprise. The publication includes a description of the author’s approach to innovation in the industrial enterprise, implemented in the form of a database. The main functions of the database are divided into two main stages – preparatory and informative. The functions of the preparatory stage include the collection of information about the industrial enterprise, the rationale for the choice of innovation, determination of the composition and administration of training (retraining), justification of the technical appearance of innovation. At the supporting stage, the database allows information support in the development and implementation of innovations in terms of timing, volume and costs, to carry out a priori and a posteriori evaluation of the quality of innovation on the basis of situational norms, as well as support for decision-making on innovation management in the industrial enterprise. The database is based on the theory of system analysis, the basic principles of the theory of innovation, methods of situational modeling, graph theory and probability theory. The results of the developed database can be used by modern industrial enterprises in the implementation of innovations.

An interlaboratory study of the determination of digoxin by immunoassay.

1980 ◽  
Vol 26 (3) ◽  
pp. 480-486
Author(s):  
D M Fast ◽  
W H Hannon ◽  
C A Burtis ◽  
D D Bayse
Keyword(s):  
Frequency Distribution ◽  
Statistical Difference ◽  
Analytical Data ◽  
Statistical Information ◽  
Mean Values ◽  
Clinical Laboratories ◽  
The Mean ◽  
Computational Procedures

Abstract We conducted a voluntary survey of laboratories and manufacturers to assess the current quality of analytical assays for serum digoxin. More than 300 clinical laboratories and 18 manufacturers responded, giving data on methods, instruments, computational procedures, and results for five survey samples. We sorted the analytical data to provide statistical information on the grand mean values separately for manufacturers and clinical laboratories, the frequency distribution of all reported values, and the mean values by method of interpolation and algorithms used for linear transformation. There was no statistical difference (alpha = 0.05) between the means for each specimen as determined by the kit manufacturers as a group and the clinical laboratories as a group.

scholarly journals Issues in Outcomes Research: An Overview of Randomization Techniques for Clinical Trials

2008 ◽  
Vol 43 (2) ◽  
pp. 215-221 ◽  
Author(s):  
Minsoo Kang ◽  
Brian G. Ragan ◽  
Jae-Hyeon Park
Keyword(s):  
Clinical Trials ◽  
Athletic Training ◽  
A Priori ◽  
Evidence Based ◽  
Random Assignment ◽  
Treatment Groups ◽  
The Past ◽  
Adaptive Techniques

Abstract Objective: To review and describe randomization techniques used in clinical trials, including simple, block, stratified, and covariate adaptive techniques. Background: Clinical trials are required to establish treatment efficacy of many athletic training procedures. In the past, we have relied on evidence of questionable scientific merit to aid the determination of treatment choices. Interest in evidence-based practice is growing rapidly within the athletic training profession, placing greater emphasis on the importance of well-conducted clinical trials. One critical component of clinical trials that strengthens results is random assignment of participants to control and treatment groups. Although randomization appears to be a simple concept, issues of balancing sample sizes and controlling the influence of covariates a priori are important. Various techniques have been developed to account for these issues, including block, stratified randomization, and covariate adaptive techniques. Advantages: Athletic training researchers and scholarly clinicians can use the information presented in this article to better conduct and interpret the results of clinical trials. Implementing these techniques will increase the power and validity of findings of athletic medicine clinical trials, which will ultimately improve the quality of care provided.

scholarly journals THE ESTIMATION OF PRECISIONS IN THE PLANNING OF UAS PHOTOGRAMMETRIC SURVEYS

2018 ◽  
Vol XLII-2 ◽  
pp. 837-843
Author(s):  
D. Passoni ◽  
B. Federici ◽  
I. Ferrando ◽  
S. Gagliolo ◽  
D. Sguerso
Keyword(s):  
A Priori Estimates ◽  
A Priori ◽  
Surface Model ◽  
Ground Sample ◽  
Quality Of Results ◽  
Small Areas ◽  
Priori Estimates ◽  
Real Geometry ◽  
A Priori Estimation

The Unmanned Aerial System (UAS) is widely used in the photogrammetric surveys both of structures and of small areas. Geomatics focuses the attention on the metric quality of the final products of the survey, creating several 3D modelling applications from UAS images. As widely known, the quality of results derives from the quality of images acquisition phase, which needs an a priori estimation of the expected precisions. The planning phase is typically managed using dedicated tools, adapted from the traditional aerial-photogrammetric flight plan. But UAS flight has features completely different from the traditional one. Hence, the use of UAS for photogrammetric applications today requires a growth in knowledge in planning.<br> The basic idea of this research is to provide a drone photogrammetric flight planning tools considering the required metric precisions, given a priori the classical parameters of a photogrammetric planning: flight altitude, overlaps and geometric parameters of the camera. The created “office suite” allows a realistic planning of a photogrammetric survey, starting from an approximate knowledge of the Digital Surface Model (DSM), and the effective attitude parameters, changing along the route. The planning products are the overlapping of the images, the Ground Sample Distance (GSD) and the precision on each pixel taking into account the real geometry. The different tested procedures, the obtained results and the solution proposed for the a priori estimates of the precisions in the particular case of UAS surveys are here reported.

scholarly journals ESTIMATION OF THE EFFECT OF PARTINGS TO THE QUALITY OF RECOVERABLE LIGNITE MINED FROM MULTI-LAYERS DEPOSITS

2004 ◽  
Vol 36 (1) ◽  
pp. 274
Author(s):  
Μ. Γαλετάκης ◽  
Κ. Παπανικολάου
Keyword(s):  
Expert System ◽  
Analytical Data ◽  
Quality Parameters ◽  
Quality Characteristics ◽  
Borehole Data ◽  
Basic Quality ◽  
Estimation Precision ◽  
Lignite Deposits

The evaluation of multi-layers lignite deposits is mainly based on borehole data. The lack of sufficient number of analytical data of waste and carbonaceous layers, leads to the use of indicative values during the evaluation and consequently affects the estimation precision of recoverable lignite quality. In the present work the possibility of determination of basic quality parameters of waste and carbonaceous layers by using an expert system was investigated. The development of the expert system was based on the available analytical data of waste and carbonaceous layers and the coded descriptions of corresponding cores. The expert system was used for the estimation of quality characteristics of waste and carbonaceous layers from selected core of Southern Field mine of Ptolemais area. The quality characteristics of the estimated recoverable lignite shows a more intense fluctuation compared with this obtained by using indicative values for waste and carbonaceous layers.

An interlaboratory study of the determination of digoxin by immunoassay.

1980 ◽  
Vol 26 (3) ◽  
pp. 480-486 ◽  
Author(s):  
D M Fast ◽  
W H Hannon ◽  
C A Burtis ◽  
D D Bayse
Keyword(s):  
Frequency Distribution ◽  
Statistical Difference ◽  
Analytical Data ◽  
Statistical Information ◽  
Mean Values ◽  
Clinical Laboratories ◽  
The Mean ◽  
Computational Procedures

Abstract We conducted a voluntary survey of laboratories and manufacturers to assess the current quality of analytical assays for serum digoxin. More than 300 clinical laboratories and 18 manufacturers responded, giving data on methods, instruments, computational procedures, and results for five survey samples. We sorted the analytical data to provide statistical information on the grand mean values separately for manufacturers and clinical laboratories, the frequency distribution of all reported values, and the mean values by method of interpolation and algorithms used for linear transformation. There was no statistical difference (alpha = 0.05) between the means for each specimen as determined by the kit manufacturers as a group and the clinical laboratories as a group.

Determination of relative position of antenna system and RGB-D sensor in combined microwave imaging system

Antennas ◽  
2021 ◽  
Author(s):  
V. V. Razevig ◽  
S. I. Ivashov ◽  
А. S. Bugaev ◽  
A. V. Zhuravlev
Keyword(s):  
Computer Modeling ◽  
Relative Position ◽  
Imaging System ◽  
Antenna System ◽  
Microwave Imaging ◽  
Optical Data ◽  
Radar Signal ◽  
Radar Images ◽  
Base Points

Microwave imaging technique allows obtaining images of hidden objects in structures and media using microwaves. This technique has various applications such as: nondestructive testing, medical imaging, concealed weapon detection, through-the-wall imaging, etc. Obtaining radar images in these applications is based on processing phase and amplitude of the reflected signal recorded over an aperture (a microwave hologram). Recently, systems began to appear in which the radar part is supplemented by an RGB-D sensor, which allows to obtain new capabilities. For example, there is the a microwave screening system architecture in which inverse synthetic aperture is formed by the natural motion of the subject in the vicinity of a stationary linear antenna array. The microwave system is complemented with an synchronous RGB-D video sensor which captures the trajectory of the moving subject in 3D and allows coherent processing of the radar signal. Another system detects objects buried under irregular surface and uses RGB-D sensor for capturing the surface relief for suppressing reflection of the sounding signal from the surface. Calibration between a radar and an RGB-D sensor is an essential process for microwave and optical data fusion. This article presents a novel approach for calibration, using a planar calibration target which is made of radiotransparent material (such a foam plastic sheet) with square marker and six small metal balls embedded in target surface and representing point objects. The proposed method exploits 3D-3D correspondences between coordinates of point objects in two coordinate systems associated to the sensor and to the radar. One points set is extracted from optical data, using marked corners of the target as a base points. Second points set is obtained from microwave data as local maxima of 3D volume of data reconstructed from one-frequency microwave hologram. Computer modeling were performed using Autodesk 3ds Max software by which models of all components of the system were built and the optical image from the sensor was modeled. Test experiments were carried out using a measurement system composed of the following components: a compact vector network analyzer (VNA), two mechanical scanners with stepper motors, one transmitting and one receiving horn antennas, mounted on the VNA, an RGB-D sensor, a microcontroller board, and a computer. The high accuracy of the method is confirmed both by computer modeling and physical experiment. The accuracy of determination of relative position between the radar and the sensor is about one fifth of the signal wavelength used.

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