GEOGRAPHICAL NAMES IN UNINHABITED REGIONS AND THE CONTROVERSY OVER THE MOUNT EVEREST MAP

Abstract

(I) The deserts of India and Baluchistan.—In the eastern half of the Great Indian Desert there are rock-outcrops projecting above the sand at in tervals averaging twenty miles; these have been landmarks for travellers for centuries, and consequently they all have native names. In the western desert there are no outcrops and no objects to name; but the desert nomads and the camel-breeders do have names for vague undefined areas, which seem to move as the sandhills move. The rock-outcrops in Baluchistan are larger and more numerous, and many are consequently without Baluchi names. Nothing would have been gained from inventing names; names are for use, not for show, and the desert people know their own requirements. It is better on a map to limit the nomenclature to the names that have been born of the people and that have stood the test of time than to supplement them with fictitious names. Survey stations on unnamed hills are therefore generally designated by symbols such as B45.     

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.     

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.     

Identifying damage caused by the 2008 Wenchuan earthquake from VHR remote sensing data

Abstract

The paper discusses the potential of very high resolution (VHR) satellite imagery for post-earthquake damage assessment in comparison with the role of aerial photographs. Post-disaster optical and radar satellite data are assessed for their ability to resolve collapsed buildings, destroyed transportation infrastructure, and specific land cover changes. Optical VHR imagery has shown to be effective in quantifying building stock and for assessing damage at the building level. High-resolution synthetic aperture radar (SAR) imagery requires further research to identify optimum information extraction procedures for rapid assessment of affected buildings. Based on current technical and operational capabilities increasing efforts should be devoted to the generation of spatial datasets for disaster preparedness.     

基于中型固定翼无人机航摄系统的大比例尺测图精度评估探讨

针对低空无人机航摄系统工作效能与测量精度方面的问题,笔者所在团队研发了一套无人机航摄系统,在新疆和田某荒漠区开展了航摄试验,对无人机航摄系统获取的航摄影像平面精度及测高精度进行评估,结果表明:成像结果可以满足1∶1 000地形图测图的平面精度要求。     

非球形冰晶的毫米波k-Ze关系研究

针对毫米波雷达处理数据的实际需要,应用离散偶极子近似法DDA,获得了非球形冰晶的后向散射及衰减截面并进行了参数化,并主要基于细化的冰云模型,假设冰晶粒子谱为Γ分布,通过模拟取样各1330次（代表1330种粒子分布）,分别计算得到了W波段（94 GHz）与Ka波段（35 GHz）毫米波雷达探测的冰云衰减系数k及雷达反射率因子Z_e,而且利用数值模拟的方法,建立了k-Z_e关系的具体表达式。计算表明,非球形和非瑞利散射对W波段毫米波雷达衰减的影响较大,而且在同样滴谱分布条件下,W波段毫米波雷达的衰减比Ka波段毫米波雷达的大几倍,此外细化的冰云模型对k-Z_e关系具有影响。本研究对中纬度非降水性冰云的毫米波雷达的衰减订正具有参考价值,并对中国的毫米波雷达应用具有借鉴作用。     

Geological interpretation of radar images

Side-looking airborne radar systems (SLAR), which produce fair quality images of the earth’s surface, have been developed over the past twenty years. These systems provide synoptic information over large areas with great speed. In regions where constant cloud cover prevents or hampers aerial photography, radar can be a source of valuable information: however, in less adverse weather conditions and at larger scales single radar images, until quite recently the normal presentation, cannot compete with conventional, stereoscopically viewed aerial photographs. It has now become common practice to take parallel strips with a large, 30–60%, overlap and scanned from the same direction. In this way a stereoscopic effect may be obtained, which considerably improves the interpretation possibilities of such radar images. The same analytical techniques used in photo-geology can also be applied to radar-interpretation. In order to obtain optimal results, the geologist who interprets radar images should have some understanding of radar operation.     

无人机航测应用于沙漠地区1∶2000地形测图

无人机低空航测摄影技术已成为目前最重要的测绘手段,其具有快速获取信息、地面分辨率高的优势。本文根据沙漠地形地貌的特点,选取飞前布控野外地标点的方案来进行空三解算与正射纠正,提高了影像的几何精度。利用点云地形点采集方法便捷高效的生成等高线,使最终地形图的平面和高程精度达到了1∶2000地形图的要求,为无人机在沙漠地形测量中的应用提供了一套完整的解决方案。     

THE MAPPING AND STUDY OF THE ISSYK-KUL' SHORELINE WITH AIR PHOTOS

Efforts to monitor and map the changing water level and shoreline of a large mountain lake in Central Asia with aerial photographs are described. The essence of the work involved the mapping of the shoreline and position of river deltas from air photos from various years during the period 1949-1980, at uniform scale and at a level of accuracy permitting the quantitative (cartometric) as well as qualitative assessment of change. The sequence of work in compilation of map-diagrams for different parts of the shoreline involved the preliminary referencing of photos to a map, photo interpretation and compilation of large-scale “graphic diagrams,” preparation of a cartographic base, reduction and placement of diagrams on the base, and transformation of the image as a whole. Results of analysis of these map-diagrams are summarized. Translated from: Vestnik Leningradskogo Universiteta, ser. 7: geologiya, geografiya, 1986, No. 2, pp. 44-48.     

ANALYSIS OF THE CHEMICAL POLLUTION OF BUFFER ZONES BY MODELING AND SUB-SATELLITE EXPERIMENTS

Principles are outlined for the use of sub-satellite soil, air, water, and vegetation samples as an auxiliary source of information in remote sensing studies of vegetation stress caused by air pollution. More specifically, procedures for satellite-synchronous aerial overflights, vegetation transects, water quality measurements, and soil tests are described as a basis for delineating boundaries between areas of vegetation stress and unpolluted areas in an industrialized area in the central Urals. Translated from: Kosmicheskiy monitoring biosfery, Yu. A. Izrael', V. V. Bugrovskiy, and Yu. V. Novikov, eds. Leningrad: Gidrometeoizdat, 1985, pp. 93-99.     

REMOTE SENSING IMAGERY AND ECOLOGICAL PROBLEMS OF COASTAL ZONES

Materials derived from aerial and space surveys provided the basis for compilation of a series of geomorphological, geological, morphostructural, and lithodynamic maps as well as a map showing sources of manmade pollution. A derivative map of geoecological regions based on these maps makes it possible to estimate qualitatively the ecological state of any coastal region. The Buor-Khaya Gulf of the Laptev Sea is used as a test case. Translated by Edward Torrey, Alexandria, VA 22308 from: Geomorfologiya, 1995, No. 4, pp. 23-34.     

THE STUDY AND MAPPING OF HUMAN IMPACTS ON NATURE IN DIFFERENT REGIONS OF THE USSR USING SPACE IMAGERY

The authors present the results of experiments in the use of remote sensing imagery for construction of maps depicting human modification of nature. Four diverse areas within the USSR were selected as mapping sites, providing a broad range of environmental and land-use characteristics for investigation. Human impacts were most effectively mapped for two desert sites. The authors recommend combining satellite imagery with terrestrial spectrometric observations or color-infrared photography in investigations of environmental change in steppeland and forested territory. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1984, No. 6, pp. 11-18.     

REMOTE SENSING IN THE SOLUTION OF SCIENTIFIC AND ECONOMIC PROBLEMS IN CUBA

Remote sensing inventories of the land and marine resources of Cuba, both from satellite and aerial platforms, are assessed in terms of their contributions to research on the country's physical and economic geography. Under the auspices of an international cooperative program “Interkosmos,” maps of many types have been upgraded, the costs of surveys have been reduced dramatically, and the potential for monitoring natural and human-induced change is being realized more fully. In addition, a study of weather and other conditions affecting image quality led to a determination of optimal times for conducting remote sensing surveys. Translated from: Vestnik Moskovskogo Universiteta, geografiya, 1988, No. 3, pp. 36-41, by Edward Torrey, Alexandria, VA 22308.     

Use of Kendall's coefficient of concordance to assess agreement among observers of very high resolution imagery

Ground-based vegetation monitoring methods are expensive, time-consuming and limited in sample size. Aerial imagery is appealing to managers because of the reduced time and expense and the increase in sample size. One challenge of aerial imagery is detecting differences among observers of the same imagery. Six observers analysed a set of 1-mm ground sample distance aerial imagery for graminoid species composition and important ground-cover characteristics. Kendall's coefficient of concordance (W) was used to measure agreement among observers. The group of six observers was concordant when assessed as a group. When each of the observers was assessed independently against the other five, lack of agreement was found for those graminoid species that were difficult to identify in the aerial images.     

Co-polarization channel imbalance determination by the use of bare soil

This paper describes a novel technique which determines the co-polarization channel imbalance by the use of natural bare soil, instead of a trihedral corner reflector (CR). In polarimetric synthetic aperture radar (PolSAR) remote sensing, the polarimetric calibration (PolCAL) is the key technique in quantitative earth parameter measurement. In general, the current PolCAL process can be separated into two parts. The first part tries to estimate the crosstalk and the cross-polarization (x-pol) channel imbalance components by the reflection symmetry and the reciprocity properties, without a CR. Then, at least one trihedral CR is required to determine the co-polarization (co-pol) channel imbalance; however, it is not always possible to deploy a CR in difficult terrain such as desert. In this paper, we utilize bare soil as a stable reference target, and four common natural constraints of bare soil are evaluated to determine the co-pol channel imbalance, without the use of a CR. It should be mentioned that we do not propose to replace the CR by a natural target, but we utilize the natural target to enhance the PolCAL accuracy when a CR is missing. The four constraints are: (1) the consistency of the polarimetric orientation angle (CPOA) between the PolSAR POA and the digital elevation model (DEM) derived POA; (2) the unitary zero POA (UZPOA) of a flat ground surface; (3) the zero helix (ZHEX) component of the ground surface; and (4) the unitary version of the previous zero helix (UZHEX). In the theoretical part of this paper, we demonstrate that the forth constraint is the most suitable in different scenes. We then propose a multi-scale algorithm to further improve the robustness of the co-pol channel imbalance determination. In the experimental part, we apply our new methods to simulated airborne SAR (AIRSAR) and real uninhabited aerial vehicle SAR (UAVSAR) data. Without the use of any CR, the recovered results show that the estimated amplitude and phase error of the co-pol channel imbalance are less than 0.5 dB and 5°, respectively.     

京西地区多种遥感图像地质解译效果评价

笔者以京西王平村地区作为评价区,对多种遥感图像在地质上的解像能力进行了比较和评述。指出了彩红外像片,侧视雷达像片和陆地卫星图像的应用条件,并分析了各种图像在解译中的优势和不足。     

Utilizing Geo-information Tools for Mapping Spatio-temporal Changes in Population of <Emphasis Type="Italic">Prosopis cineraria</Emphasis> (khejri) in Agroforestry System of Arid Western Rajasthan

The present study is an attempt to assess the spatial variability and the changes in the population of Prosopis cineraia (khejri) trees in the agroforestry systems of arid part of western Rajasthan. This tree is regarded as an important natural resource for the rural livelihood of desert dwellers because of its multifarious uses. The tree populations were mapped in a geographical information system using available information from aerial photographs, google earth images and IRS-LISS-III satellite images to compare their populations between the past and the very recent period. Mapping carried out in a part of Nagaur district in western part of Rajasthan, indicated increase in khejri trees in the region in 2013–2014 compared to 1960s. The number and tree density were higher under irrigated croplands than under rainfed. Increase in rainfall, multiple uses of the tree, societal and scientific support are the key reasons for the observed changes in their population.     

Representation of Populated Places on Radar Imagery

Russian specialists in the application of radar imagery to the study of geographical problems survey its use in the study of urban settlements. More specifically, they are concerned with the types of patterns and tonal signatures (optical densities) manifest on centimeter-band radar imagery, corresponding to buildings and other structures of various heights, dimensions, and construction materials. Cities and smaller urban and rural settlements in Vitebsk Oblast of Belarus and Voronezh Oblast of Russia are compared with respect to such information derived from radar images. Translated by Edward Torrey, Alexandria, Virginia from: Geografiya i prirodnyye resursy, 2002, No. 4, pp. 138-140.     

Calibration of digital camera integration accuracy for low-cost oblique aerial photogrammetry

This work describes a calibration process for inexpensive consumer cameras integrated into a low cost and compact aerial multi-view imager for remote sensing and photogrammetry. The main advantage of this design is to make the filming component lightweight and rapidly deployable, as well as reducing cost when compared with mainstream commercial oblique imagery. An in situ flight test was carried out in Guiyang. In that experiment, a meridian convergence-based approach was adopted to adjust preprocessing, the residue error and the captured images’ exterior orientation linear and angular parameters were calculated by means of the direct geo-referencing approach yielding a favorable outcome for exterior orientation linear parameters of the camera, around 0.2–0.3 m deviation from the actual measured results at 1000 m flight above ground level. The camera’s exterior orientation angular parameters φ, ω whose difference compared with the standard aerial aero triangulation approach reached a high accuracy level within the intended endurance of 0.005°. These results indicate that the compact implementation of the oblique aerial imager comprised of consumer level off-the-shelf digital cameras achieved competitive accuracy at a low cost and high versatility.     

Relationship of local incidence angle with satellite radar backscatter for different surface conditions

This paper examines the relationship of C-band radar backscatter from the Advanced Synthetic Aperture Radar on board the ENVISAT satellite with the local angle of incidence, whose influence on the received signal is significant, particularly in the modes of sensor operation that use the full swath of the orbit track. Linear regression is carried out for each pixel throughout a large time series of radar data over the whole of the state of Queensland, Australia, and at Great Salt Lake, Utah, USA. In the first case, the resultant coefficients are analysed for correlation against various parameters, with regolith showing the highest correlation. Class separability analysis shows the potential to use the resultant coefficients as a supplement to absolute threshold values in order to distinguish between classes of vegetation and/or geology, where cloud cover may preclude the use of optical data. It is observed that the separability between water and land is greatly higher using the slope coefficient B than using backscatter σ⁰, which may be of great benefit in the remote sensing of water where cloud cover is present (from which radar is largely independent). This is especially the case when considering the observed overlapping of backscatter values from water, with values from aeolian sand and lacustrine and alluvial sediments, rendering the use of backscatter alone problematic. In order to test the potential use of B to map water extents, the study over the Great Salt Lake compares the classification accuracy of B against that of σ⁰. It is found that the σ₀ classification misrepresents desert, salt flat and dry lake basin areas, where the B classification differentiates these regions accurately. The resultant classification achieves a kappa statistic around 0.9, which shows very high conformance. An accurate and novel method to classify water is therefore demonstrated, which awaits the launch of anticipated improved synthetic aperture radar instruments on satellite missions in the coming few years.