IMAGE INTERPRETATION AS A SYSTEM OF SCIENTIFIC RESEARCH

The article provides insights derived from conceptualization of the totality of elements (subsystems) of image interpretation as part of a larger system of scientific research. Among the elements discussed in some detail in terms of their impacts on the appearance of features interpreted on remote sensing imagery include solar radiation, the atmosphere, distinctive characteristics of the surface of the area being imaged, the remote sensors employed for image recording, processing techniques, the image medium, and the “human” element (interpreter). It then describes an evolutionary process in image interpretation by which knowledge gained in early stages represents an input leading to refinement of approaches employed in later stages. A final section describes factors contributing to dynamics (“scintillation” or “flickering”) of features on imagery of the same area but recorded at different times or under different imaging conditions. Translated by Edward Torrey, Alexandria, VA 22308 from: Izvestiya Akademii Nauk, seriya geograficheskaya, 1993, No. 3, pp. 102-109.     

Terrain radiometric calibration of airborne UAVSAR for forested area

In the field of biomass estimation, terrain radiometric calibration of airborne polarimetric SAR data for forested areas is an urgent problem. Illuminated area correction of σ -naught could not completely remove terrain features. Inspired by Small and Shimada, this paper tested gamma-naught on one mountainous forested area using airborne Uninhabited Aerial Vehicle Synthetic Aperture Radar data and found it could remove most terrain features. However, a systematic increasing trend from far range to near range is found in airborne SAR cases. This paper made an attempt to use the relationship between distance to SAR sensor and γ-naught to calibrate γ -naught. Two quantitative evaluation methods are proposed. Experimental results demonstrate that variation of γ -naught can be constrained to a limited extent from near range to far range. Since this method is based on ground range images, it avoids complicated orthorectification.     

SELECTION OF AN OPTIMAL ALGORITHM FOR RECOGNITION OF NATURAL FEATURES

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.     

USE OF SPACE IMAGERY IN THE STUDY OF MASS EXCHANGE IN GLACIER SYSTEMS

The author surveys the use of remote sensing imagery in the study of mass exchange in glaciers, i.e., glacier dynamics resulting from phase changes in the water which they contain. A program of research now underway at the Institute of Geography (USSR Academy of Sciences) in conjunction with the “Priroda” Remote Sensing Center (Moscow) focuses on improving methods of data collection and mapping of glacier dynamics from space imagery, and particularly on identifying natural glacioclimatic zones believed to represent specific mass exchange conditions or regimes. The boundary of glacier nourishment separating areas of accumulation and ablation represents a key glacioclimatic indicator of mass exchange on satellite imagery and aerial photography. Translated from: Geodeziya i kartografiya, 1986, No. 5, pp. 26–31.     

Analysis of population dynamics using satellite remote sensing and US census data

The population dynamics from 1991 to 2006 for the seven-county Twin Cities Metropolitan Area (TCMA), Minnesota, USA, was analysed in this study. Per cent impervious surface areas (%ISA) for 1991, 1999 and 2006 were derived from Landsat Thematic Mapper (TM) images and were modified using two different masking methods. The modified %ISA images of 1991 and 1999 were correlated with 1990 and 2000 census block group data of the ‘two highly developed counties’, ‘five suburban counties’ and ‘all seven counties.’ Populations of both years were then modelled, assessed and compared. Next, the statistical models based on the 1999 %ISA and 2000 census data were applied to the 2006 residential %ISA image to estimate the 2006 population. These 2006 estimates were compared with census county-level population projections for 2006. In comparison to Method A, which uses ‘adjusted %ISA images’ by masking out highway centrelines and areas that have greater than 75% imperviousness, Method B based on ‘pure residential %ISA image’ has higher coefficient of determination (R ²) and much lower, consistent mean absolute relative errors (MARE). For both methods, the strongest R ² and lowest MARE values between modelled population density and true density were found in the five-county model, followed by the seven-county model. The two-county model ranks last in terms of model performance for both years. In general, populations for the two highly developed counties were underestimated whereas the opposite was true for the five suburban counties. Population was most accurately estimated based on data from counties with the same or similar characteristics. By comparing the 1990/1991 and 1999/2000 models, we also found that the rate of population density per unit of impervious surface declined from 1991 to 1999. High accuracy was achieved when applying the 1999/2000 model to predict the 2006 population, suggesting that the relationship between per cent imperviousness and population density were relatively stable between 1999 and 2006.     

REMOTE SENSING IN THE MORPHOMETRIC ANALYSIS OF CHANNELS AND FLOODPLAINS

The first of two papers devoted to the analysis and mapping of river channels and floodplains describes Soviet work in the photogrammetric and cartometric analysis of floodplain morphology based on remote sensing imagery. The emphasis of the present paper is on the creation of digital terrain models for the automated measurement and mapping of floodplain features. Considerable attention is focused upon analysis of indicators of channel and floodplain dynamics (channel deposition, bankside erosion, meanders) appearing on aerial photographs. The results of channel analyses based on aerial photographic and field methods (determinations of channel width, depth, etc.) are compared for a test site. Translated from: Geomorfologiya, 1986, No. 4, pp. 51-57.     

Automated geometric correction of multispectral images from High Resolution CCD Camera (HRCC) on-board CBERS-2 and CBERS-2B

China–Brazil Earth Resource Satellite (CBERS) imagery is identified as one of the potential data sources for monitoring Earth surface dynamics in the event of a Landsat data gap. Currently available multispectral images from the High Resolution CCD (Charge Coupled Device) Camera (HRCC) on-board CBERS satellites (CBERS-2 and CBERS-2B) are not precisely geo-referenced and orthorectified. The geometric accuracy of the HRCC multispectral image product is found to be within 2–11 km. The use of CBERS-HRCC multispectral images to monitor Earth surface dynamics therefore necessitates accurate geometric correction of these images. This paper presents an automated method for geo-referencing and orthorectifying the multispectral images from the HRCC imager on-board CBERS satellites. Landsat Thematic Mapper (TM) Level 1T (L1T) imagery provided by the U.S. Geological Survey (USGS) is employed as reference for geometric correction. The proposed method introduces geometric distortions in the reference image prior to registering it with the CBERS-HRCC image. The performance of the geometric correction method was quantitatively evaluated using a total of 100 images acquired over the Andes Mountains and the Amazon rainforest, two areas in South America representing vastly different landscapes. The geometrically corrected HRCC images have an average geometric accuracy of 17.04 m (CBERS-2) and 16.34 m (CBERS-2B). While the applicability of the method for attaining sub-pixel geometric accuracy is demonstrated here using selected images, it has potential for accurate geometric correction of the entire archive of CBERS-HRCC multispectral images.     

结合UPSCALING技术与对象多特征的土地利用覆盖信息提取研究

应用SPOT融合数据,以北京密云地区为例,提出了整合Upscaling技术与对象多特征方法的新思路,通过基于半变异函数的 空间变异特征分析,建立了面向对象多特征与多分辨率数据集的多尺度分类决策树,并对自动分类效率进行了初步探讨。     

GROUND CONTROL DETERMINATION FOR REGISTRATION OF SATELLITE IMAGERY USING DIGITAL MAP DATA

Work is reported on the production of terrain elevation data from SPOT imagery. An important step in this process is determination of exterior orientation parameters for the images. Although an initial estimate is available in the SPOT header, refinements are required based on plan and height data. These are generally derived from photogrammetric measurements (or sources such as global positioning satellite systems), but accurate manual determination is time consuming. This paper reports an alternative approach by investigating the use of existing map data (located on the earth's surface and in a known projection) to find corresponding “ground control points” in both map and image. Available maps may be in digital or paper form depending on the state of development of mapping in the part of the world being studied. The last revision date and the cartographic generalisation employed will also effect the fidelity of the final result. Practical semi-automatic techniques for determining the height of ground control points from existing map data are described, including multiple profiles through digitised contour data, a commercial terrain modelling package based on Delaunay triangulation and the use of triangulation points on prominent features. Comparisons between the methods are made and results obtained are compared with Institut Géographique National datasets and photogrammetric measurements. Methods for fully automating not only the height determination but also the location of ground control features within a map database are discussed. Map and image registration is described and illustrated using Laser-Scan's Rover software. Interactive and automated methods of registration are discussed.     

DEVELOPMENT OF QUANTITATIVE METHODS OF STUDYING THE EARTH FROM SPACE

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.     

AERIAL PHOTOGRAPHIC STUDIES OF THE MARINE ECOLOGY OF THE WHITE SEA

Aerial photographic surveys of the White Sea have proven to be an effective means for studying the character of bottom relief and bottom sediments in shallow areas along its coast, particularly when film sensitive to visible radiation in the yellow-green range of the spectrum is used. More specifically, the article discusses methods of aerial photographic surveying, keys for the interpretation of different types of bottom sediments, methods of mapping underwater vegetation from air photos, and the potential of radar imagery for the indirect interpretation of bottom features. Sample interpretation maps from the White Sea are included. Translated by Edward Torrey, Alexandria, VA 22308 from Izvestiya Vsesoyuznogo Geograficheskogo Obshchestva, 1988, No. 4, pp. 314-321.     

Retrieving spatial variations of land surface temperatures from satellite data–Cairo region,Egypt

Cairo region is characterized by a range of physiographic features, including: flat agricultural lands, bare sandy deserts, highlands, calcareous terrains and urban land use. A time series data-set (300 images) acquired from the Moderate Resolution Imaging Spectroradiometer for the period July 2002–June 2015 were utilized to retrieve the spatial variations in the mean land surface temperature (LST) for the above-mentioned surface features. Results showed that vegetation, topography and surface albedo have negative correlations with LST. Vegetation/LST correlation has the maximum regression coefficient (R² = 0.68) and albedo/LST has the minimum (R² = 0.03). Cultivated lands reveal the lowest mean LST (<32 °C), whereas industrial lands exhibit the highest LST (>40 °C) of Cairo region. There is a considerable urban heat island formed at Helwan south of Cairo, where heavy industries are settled. Industrial activities raised the mean LST of the region by at least 4 °C than the surrounding urban lands.     

SPOT-7遥感图像融合技术对比研究

随着高分辨率影像研究的发展,影像融合成为遥感影像处理领域中一个重要的研究方向。目前对于影像的融合已有很多的方法,如IHS法、HPF法等。本文将以SPOT-7高分辨率影像作为研究对象,探讨经PCA法、Pansharpening法、Gram-Schmidt法、NNDiffuse法这4种融合方法,融合后的影像在保持地物的波谱特征,以及信息识别效果等多方面的各自优势,并通过定性和定量评价来确定适合SPOT-7高分辨率影像的融合方法,实验结果表明:NNDiffuse方法的融合结果最为理想。     

NEW IDEAS IN A QUANTITATIVE APPROACH TO IMAGE PROCESSING

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.     

Semi-automatic delineation of badlands using contrast in vegetation activity: a case study in the lower Chambal valley,India

Population growth worldwide leads to an increasing pressure on the land. Recent studies reported that many areas covered by badlands are decreasing because parts of badlands are being levelled and converted into arable land. It is important to monitor these changes for environmental planning. This paper proposes a remote-sensing-based detection method which allows mapping of badland dynamics based on seasonal vegetation changes in the lower Chambal valley, India. Supervised classification was applied on three Landsat (Thematic Mapper) images, from 3 different seasons; January (winter), April (summer) and October (post-monsoon). Different band selection methods were applied to get the best classification. Validation was done by ground referencing and a GeoEye-1 satellite image. The image from January performed best with overall accuracy of 87% and 0.69 of kappa. This method opens the possibilities of using semi-automatic classification for the Chambal badlands which is so far mapped with manual interpretations only.     

短基线INSAR相干点探测及应用

提出一种结合子孔径相关测度的时序高相干点探测方法,首先对时序SAR影像进行谱分解获得子孔径视图,通过时序子孔径相关测度进行强散射点筛选,然后分别根据振幅离差和干涉相位空间相关性,对目标点进行相位稳定性分析,探测出既满足强散射且在时间序列上散射稳定的高相干点。利用改进的点探测方法和短基线INSAR技术,对北京2003—2009年间40景ASAR影像进行相位建模,获取地面沉降时空分布特征,分析典型地物时序沉降过程,研究北京地面沉降与地下水开采关系。结果表明:相比已有方法,本文结合子孔径相关测度的高相干点探测结果更准确可靠;利用本文点探测方法反演的历史累积沉降信息,与水准结果一致,平均速率之差在3.69 mm/a以内,中误差为1.36 mm/a;研究区地面沉降最大速率达92.25 mm/a,空间不均匀分布明显,地面沉降量与地下水开采量呈分段的非线性相关。     

AN EXPERIMENT IN SYSTEMATIZING THE CARTOGRAPHIC IMAGES OF GEOMORPHOLOGICAL FEATURES

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.     

Detection of impervious surface change with multitemporal Landsat images in an urban–rural frontier

Mapping and monitoring impervious surface dynamic change in a complex urban-rural frontier with medium or coarse spatial resolution images is a challenge due to the mixed pixel problem and the spectral confusion between impervious surfaces and other non-vegetation land covers. This research selected Lucas do Rio Verde County in Mato Grosso State, Brazil as a case study to improve impervious surface estimation performance by the integrated use of Landsat and QuickBird images and to monitor impervious surface change by analyzing the normalized multitemporal Landsat-derived fractional impervious surfaces. This research demonstrates the importance of two-step calibrations. The first step is to calibrate the Landsat-derived fraction impervious surface values through the established regression model based on the QuickBird-derived impervious surface image in 2008. The second step is to conduct the normalization between the calibrated 2008 impervious surface image with other dates of impervious surface images. This research indicates that the per-pixel based method overestimates the impervious surface area in the urban-rural frontier by 50%-60%. In order to accurately estimate impervious surface area, it is necessary to map the fractional impervious surface image and further calibrate the estimates with high spatial resolution images. Also normalization of the multitemporal fractional impervious surface images is needed to reduce the impacts from different environmental conditions, in order to effectively detect the impervious surface dynamic change in a complex urban-rural frontier. The procedure developed in this paper for mapping and monitoring impervious surface area is especially valuable in urban-rural frontiers where multitemporal Landsat images are difficult to be used for accurately extracting impervious surface features based on traditional per-pixel based classification methods as they cannot effectively handle the mixed pixel problem.     

THE CURRENT STATUS OF BATHYMETRIC MAPPING

A review article on world bathymetric mapping activity over the last quarter century from a Soviet perspective provides information about Soviet mapping programs of the deep sea and continental shelf. In addition, it addresses a number of methodological issues in bathymetric mapping which are attributed to the lag between advances in practical mapping activity and the development of cartographic theory—the selection of isobath intervals and appropriate scales for different sea floor features and intended map uses, and the proper use of layer tinting and other graphic techniques to depict variations in water depth without obscuring details of submarine topography. Translated from: Vestnik Leningradskogo Universiteta, seriya 7 [geologiya, geografiya], 1987, No. 2, pp. 62-71.     

Spatio‐temporal prediction of land surface temperature using semantic kriging

Spatio‐temporal prediction and forecasting of land surface temperature (LST) are relevant. However, several factors limit their usage, such as missing pixels, line drops, and cloud cover in satellite images. Being measured close to the Earth's surface, LST is mainly influenced by the land use/land cover (LULC) distribution of the terrain. This article presents a spatio‐temporal interpolation method which semantically models LULC information for the analysis of LST. The proposed spatio‐temporal semantic kriging (ST‐SemK) approach is presented in two variants: non‐separable ST‐SemK (ST‐SemK_NSep) and separable ST‐SemK (ST‐SemK_Sep). Empirical studies have been carried out with derived Landsat 7 ETM+ satellite images of LST for two spatial regions: Kolkata, India and Dallas, Texas, U.S. It has been observed that semantically enhanced spatio‐temporal modeling by ST‐SemK yields more accurate prediction results than spatio‐temporal ordinary kriging and other existing methods.