首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 906 毫秒
1.
Algorithms, designed for digital image processing in standard mainframe computers and representing sequential stages in a land-use classification procedure, are used to produce maps of agricultural crop types from multispectral satellite imagery. Pixel reflectance values are first grouped according to an unsupervised “rapid classification algorithm,” or data compression procedure. Mean reflectance values of the resulting classes then go into a supervised “sequential clustering algorithm” where classes are refined according to training value and other parameter inputs. The objective is to increase the accessibility of automated image interpretation while balancing classification accuracy and processing time. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1984, No. 4, pp. 63-69.  相似文献   

2.
Two widely used Soviet algorithms for the classification of hydromete-orological features are compared for the purposes of mapping water temperature, electrical conductivity, pH, transparency/turbidity, dissolved surface concentration of chemical elements, depth, etc. The KLASS algorithm, using a solution to the “traveling salesman” problem for classifying objects in feature space, produced higher intra-class proximity and greater inter-class “distances” than the KSS algorithm, based on optimizing “shortest-path” criteria. This was determined through the use of five similar measures of recognition quality. Translated from: Vestnik Leningrad-skogo Universiteta, 1985, No. 14, pp. 95-100.  相似文献   

3.
  相似文献   

4.
The authors present a statistical approach for multi-band image processing based on “synthesizing” processing methods, i.e., methods which transform N original band-specific images into a smaller number of (synthetic) image products. Such techniques are increasingly replacing “one-dimensional” methods (one-to-one correspondence between number of original and processed images) because of the normally greater informational content and enhanced feature discrimination capability afforded by composite image products. The ultimate objective is development of a complex of image processing strategies balancing user demands for information quantity, image diversity, and efficient use of computer time. Translated from: Metody kompleksnykh aerokosmicheskikh issledovaniy Sibiri, L. K. Zyat'kova, ed. Novosibirsk: Nauka, 1985, pp. 84-87.  相似文献   

5.
The authors attempt to identify and standardize the cartographic symbols (“images”) used to represent a variety of specific geomorphological features. A large number of cartographic representations of landform features found on geological-geomorphological maps are classified in terms of their basic pattern/configuration and the level of complexity within each major pattern type. It is argued that the pattern or configuration of a cartographic symbol used to represent a geomorphological feature should represent the spatial structure of that feature with sufficient reliability to serve as a key to an understanding of its genesis. Translated from: Geomorfologiya, 1987, No. 2, pp. 62-66.  相似文献   

6.
The paper surveys the development of “space geography”–a field of knowledge applying the methods of remote sensing, the physical sciences, and mathematics in the solution of geographic problems. Early advances featured methodological improvements (use of quantitative methods in image processing), whereas future research must focus upon perfecting our knowledge of: (a) relationships underlying the use of these methods, i.e., between environmental parameters and reflectance values, (b) methods of effectively combining different types of imagery, and image products and field work, in research, and (c) appropriate quantitative indices for feature recognition. Examples of the operationalization of such concerns are demonstrated for land-use and soil mapping projects. Translated from: Izvestiya, AN SSSR, seriya geograficheskaya, 1985, No. 5, pp. 110–116.  相似文献   

7.
Principles and objectives governing Soviet thematic mapping of nearby planets are outlined, types of information sources for such mapping categorized, and the suitability of different types of information sources for thematic mapping are evaluated. This is followed by a classification of thematic planetary maps according to type. The need for a standardized, systems approach to the determination of map scales, compilation and generalization, symbolization, and map design is emphasized as an essential prerequisite for the development of complex atlases of individual planets, atlases of “comparative planetology,” and the establishment of “planetary information systems.” Translated by Jay Mitchell; PlanEcon, Inc.; Washington, DC 20005 from: Vestnik Moskovskogo Universiteta, geografiya, 1987, No. 6, pp. 60-67.  相似文献   

8.
Heterochronous multispectral imagery from the “Fragment” scanner is used to identify and map a series of “natural-agricultural complexes,” or agricultural landscapes, of southern European Russia. Interpretation is based on imagery in the green, orange, red, and near-infrared zones of the spectrum (0.5-1.1 μm). Interpretation keys and other information designed to facilitate feature discrimination (optimal wavelengths, best seasons for imagining) are provided in many instances. Natural landscape and soil erosion maps are also compiled from the imagery, which supply information (an optimal crop rotation scheme and needed reclamation measures) used on the agricultural landscape map. Translated from: Vestnik Moskovs-kogo Unlversiteta, geografiya, 1985, No. 2, pp. 34-41.  相似文献   

9.
Feature classification maps derived from visual and automated methods of interpreting band-specific and composite imagery from the “Fragment” multispectral scanning system are compared in the study of vegetation and related features along the Gulf of Riga. The automated method, featuring a two-stage unsupervised/supervised classification algorithm developed at Moscow University (see MSRS, 1984, No. 3, pp. 255-261) provided for enhanced discrimination of wetland areas, farm land, and settlements, as well as for the elimination of extraneous components (especially the above) visually classified as deciduous forest. Translated from: Vestnilk Moskovskogo Universiteta, geografiya, 1988, No. 3, pp. 49-57 by Jay K. Mitchell, PlanEcon, Inc., Washington, DC 20005.  相似文献   

10.
《测量评论》2013,45(11):264-268
Abstract

I may say at once that this article has nothing to do with either the Gaiety chorus or the “Old Firm”: it is merely a statement of what seem to me the fancies in Dr. de Graaff Hunter's paper “Figures of Reference for the Earth”, E.S.R., No. 8,pp. 73–8. Many readers of the Review will share my gratitude to Dr. Hunter for his lucid presentation of the theory underlying the usual geodetic processes. I disagree with only one of his points, and its implications, but unfortunately that point is fundamental.  相似文献   

11.
This first installment in a series of papers extracted from a Soviet “manual” of remote sensing describes the design, operation, and payloads of the “Meteor” and “Meteor-Priroda” earth observation satellites-the latter as name given to “Meteor” satellites used for economic land-use studies, instead of their original meteorological applications. Issues such as orbit parameters, spatial resolution, scan width, and telemetry are also addressed. Translated from: Priroda Zemli iz kosmosa, A.P. Tishchenko and S.V. Viktorov, eds. Leningrad: Gidrometeoizdat, 1984, pp. 16-24.  相似文献   

12.
G. T. M. 《测量评论》2013,45(12):346-352
Abstract

19. Formulae.—In Nos. 6, vol. i, and 9, vol. ii, pp. 259 and 156, there has been described a new method for dealing with long geodesics on the earth's surface. There the so-called “inverse” problem has claimed first attention: given the latitudes and longitudes of the extremities of a geodesic, to find its length and terminal azimuths. It remains to discuss the “direct” problem : a geodesic of given length starts on a given azimuth from a station of known latitude and longitude; to find the latitude and longitude of its extremity and the azimuth thereat. The solution of this direct problem demands a certain recasting of the formulae previously given. In order of working the several expressions now assume the forms below.  相似文献   

13.
The Annotation Process in OpenStreetMap   总被引：2，自引：1，他引：1  
In this article we describe the analysis of 25,000 objects from the OpenStreetMap (OSM) databases of Ireland, United Kingdom, Germany, and Austria. The objects are selected as exhibiting the characteristics of “heavily edited” objects. We consider “heavily edited” objects as having 15 or more versions over the object's lifetime. Our results indicate that there are some serious issues arising from the way contributors tag or annotate objects in OSM. Values assigned to the “name” and “highway” attributes are often subject to frequent and unexpected change. However, this “tag flip‐flopping” is not found to be strongly correlated with increasing numbers of contributors. We also show problems with usage of the OSM ontology/controlled vocabularly. The majority of errors occurring were caused by contributors choosing values from the ontology “by hand” and spelling these values incorrectly. These issues could have a potentially detrimental effect on the quality of OSM data while at the same time damaging the perception of OSM in the GIS community. The current state of tagging and annotation in OSM is not perfect. We feel that the problems identified are a combination of the flexibility of the tagging process in OSM and the lack of a strict mechanism for checking adherence to the OSM ontology for specific core attributes. More studies related to comparing the names of features in OSM to recognized ground‐truth datasets are required.  相似文献   

14.
The author reviews the contributions of the “aerospace” disciplines (remote sensing, photogrammetry, photometry) in the training of cartographers at Moscow University. Changes in the present curriculum are advocated, leading to the emergence of a unified educational discipline referred to alternately as “remote mapping methods,” or “remote sensing and mapping.” Training in this discipline is designed to enhance the interpretation and map compilation skills of cartographers working with space imagery. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1984, No. 5, pp. 40-43.  相似文献   

15.
《测量评论》2013,45(5):207-214
Abstract

Artillery Survey.—Included in the term “Artillery Survey are two distinct problems, the first that of determining the “line” and “range” at which fire should be opened, and the second that of laying the gun in the required line. To appreciate these problems it. is necessary to know a little about the technique of gunnery, and for the benefit of those who have no acquaintance with the subject the following brief résumé may be given.  相似文献   

16.
A survey of the use of topologic concepts of space in map transofrmation supports the author's contention that so-called “transformed images” represent for the most part rather arbitrary distortions of conventional maps constructed in Euclidean space. This paper demonstrates how truly topologic images can be created “from scratch,” i.e., without manipulation of either the sizes or shapes of areal units on preexisting maps. Images created by quantitatively defining “graphic ratios” of areal units can thus be replicated by other cartographers with a minimum of subjectivity. Translated from: Geodeziya i kartografiya, 1984, No. 12, pp. 28-31.  相似文献   

17.
《测量评论》2013,45(25):136-140
Abstract

In a previous article on this subject (Empire Survey Review, January 1937) the writer sought to show that for trigonometrical observations of vertical angles made near noon in the Tropics the coefficient of refraction depends chiefly on height above ground level in the case of stations sited within a few hundred feet above the general level of the ground surface. Indeed, the computed values of the coefficient K show a definite and appreciable increase with “h”, the height of the observing station above ground level; it is usually assumed that K decreases with increase in height above the Mean-Sea-Level surface. From analysis of the results obtained by varying h but holding the heights above Mean Sea Level fixed the writer came to the conclusion that the variations in K could only be due to abnormal values of dt/dh and d2t/dh2, “t” denoting the air temperature. Now it is generally recognized by meteorologists that abnormal lapse-rates of temperature do frequently occur in the lower air layers in the Tropics; but up to the present time no temperature soundings in Nigeria are available. Recently, however, the writer came across the results of the aerological soundings made by an expedition in East Africa during the year 1908. The results of many of the soundings were of no use for the purpose of this paper; many of the observations were not taken at or near noon, and in others counterlapses of temperature in the lower layers indicated that conditions were not normal. A set of observations taken at Mombasa between 10 and 11 a.m. were eventually chosen as offering an example of what might reasonably occur in the lower layers of the atmosphere.  相似文献   

18.
本文首先分析了遥感影像尺度的三层次内涵。重点针对遥感像元尺度,分析了遥感像元尺度效应及其分形机理,由于现有分形方法没有考虑影像本身尺度(空间分辨率),造成尺度间分形维数的比较时像元尺度效应变化难以有效反映,本文针对此问题提出了基于表面积的加窗分形布朗运动和加窗双层地毯两种改进分形方法。为验证改进分形方法的可靠性,采用了不同像元尺度下系列监督分类进行验证。试验结果表明,每种地物的分维数都随着空间分辨率的降低或像元尺度的缩小,呈总体下降趋势,在某些特征尺度上会出现预示着某些地物结构的拐点,这些拐点对观测该区域地物具有一定指示意义。系列监督分类精度也一定程度上证明了以上两种改进分形方法在分析尺度效应中的可行性。因此本文的方法对于分析遥感像元尺度效应和探索地物尺度聚合规律具有一定的理论意义。  相似文献   

19.
《测量评论》2013,45(12):329-330
Abstract

Major Hotine (E.S.R., No. II, pp. 264–8) still finds the location of a reference spheroid to offer insuperable difficulties. I confess that my difficulty is to see his! In my previous article (E.S.R., No. 8) at the foot of page 76, I used the word “coincidence” in error for “parallelism”. This harmonizes the article and I am glad that Major Hotine has directed attention to the error.  相似文献   

20.
M.H. 《测量评论》2013,45(85):326-327
Abstract

Air.—Any good Guest Night tune which happens to fit to a first order, and remains more or less in tune after subsequent orders. “Coming down the Mountain” and “Kabul River” would do.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号