基于直升机平台的南极非量测数码航空摄影测量技术研究

使用直升机作为飞行平台并应用哈苏H1D非量测数码相机进行南极中山站和拉斯曼丘陵地区摄影测量。通过对非量测相机标定,获取相机的内方位元素,从而可进行航空摄影测量。两个区域的具体试验表明基于直升机平台和非量测数码相机的航空摄影测量可应用于南极等困难地区的地形图测绘。     

An inexpensive system for continuous lake core photography

Representative images of split sediment cores document geological records, serve as visual aids for multimedia, and provide samples for image analysis. Existing core imaging systems, often containing integrated hardware and software, are capable of providing excellent images; unfortunately these systems are also bulky and expensive, and are therefore limited to labs that process large volumes of core and those actively involved in image analysis. For most research groups such systems are unfeasible to buy and maintain. Producing good quality core images with a hand-held digital camera is very difficult without a consistent lighting source, and changes in camera angle (in all three spatial dimensions) between photographs may prevent accurate image compositing. Tripods allow for camera stability, but typically do not accommodate downward-facing photography. Presented here is an easily constructed core-imaging system that minimizes many of the drawbacks of personal digital cameras. Software necessary for using this system is readily available and can be run from a personal computer.     

The application of remote sensing techniques to landscape level environmental research: A hybrid approach combining visual and digital interpretation

The development of new technology for use in environmental research provides us with numerous sophisticated tools such as remote sensing and Geographical Information Systems (GIS). However, throughout recent decades there have been debates regarding the appropriate use of these tools. The question still remains as to whether they can strengthen environmental research, or whether perhaps more conventional methods are better suited? This paper focuses on the use of remote sensing in environmental applications, such as strategic or regional environmental assessments. By providing a case study from Sri Lanka, it is shown how the benefits from a visual interpretation of satellite imagery can be combined with a digital supervised classification in a hybrid approach. The use of these techniques in environmental assessments is further discussed in the light of 'best practicable science' as proposed by the International Association of Impact Assessment (IAIA). The intention is not to discourage the use of digital techniques, but to discuss how they should be utilized to their fullest extent. The approach argued for here provides data of a more general and possibly integrative nature. It may therefore be well suited for the early screening and scoping stages of environmental assessments at a landscape level.     

An algorithm to aid varve counting and measurement from thin-sections

An algorithm has been implemented to count and measure laminations from digital images of petrographic thin-sections. Boundaries and limits of laminations are first marked manually using imaging software. These marks are then exported to a workable format output file. Using the output file, the algorithm extracts the relevant information for lamination counts and thickness measurements along one or more parallel vertical lines. Compared to manual counts, the use of the algorithm improves the accuracy of measurements and speeds up the process. The method requires tools commonly available in most laboratories, i.e., a digital camera or a flat bed scanner with transparency capability and a desktop computer with 64 MB of RAM. From the algorithm, two utilities are implemented in Visual Basic for Applications and Fortran to be used on both Apple Macintosh and a PC-compatible, with Adobe^® Photoshop^®.     

云南南滚河自然保护区大中型陆生哺乳动物初步调查

During surveys for wild felids in Nangunhe Nature Reserve, Yunnan province, China, we conducted a wider mammal survey of the core nature reserve area, using camera trapping techniques. Forty motion-triggered digital camera traps had been set in oldest forest tract of protected area to conduct a species inventory. The total camera trapping effort of 2460 camera trap nights yielded 232 digital photographs of mammals represented by 17 species in five orders. The species photographed include rare and elusive species and those that are of high conservation value, such as IUCN endangered species Asiatic elephant (Elephas maximus), and Phayre’s leaf monkey (Trachypit hecus phayrei). In addition, IUCN vulnerable species including Asiatic black bear (Ursus thibetanus), sambar (Rusa unicolor), northern pig-tailed macaque (Macaca leonine), and marbled cat (Pardofelis marmorata), and more common species were found. All mammals were also listed as key protected wild animals by the State Forestry Administration of China. Of particular importance were the carnivores, with 7 different species recorded. Ungulates and other taxa forming a prey base for these predators,such as rhesus macaque (Macaca mulatta), red muntjac (Muntiacus muntjac), sambar, wild boar (Sus scrofa), and Chinese serow (Capricornis milneedwardsii), were found to be the most frequently photographed and most widespread species. Opportunities for local people to develop standardized monitoring designs for targeted species were identified by these initial assessment results. Local nature reserve staff lacked technical ability to produce standardized survey designs, yet a by product of this type of non-standardized data collection can be very informative and produce inventory information that gives a species richness analysis, as well as initial estimates for occupancy and detection probability for abundant species to drive future standardized survey designs and efforts.     

AUTOMATED GEOGRAPHY

Analytical methods and computer technology for spatial analysis have advanced rapidly. Geographers can now consider a general form of automated geography which integrates all of the new techniques into an analytical whole. Computer cartography, computer graphics, digital remote sensing, geographic information systems, spatial statistics, and quantitative spatial modeling can be combined eclectically with traditional manual techniques to address geographic problems that are too large and complex for manual treatment alone. Small systems are widely available to facilitate small, less complex problems. Automation can assist in all forms of geography—scientific and humanistic, nomothetic and idiographic, basic and applied—but its adoption is likely to be highest among applied scientists. The immediate challenge is to prepare for a major shift toward computer instruction and automated geography in the late 1980s. Long term effects will include improved contributions by geographers to national and international policy analyses, a greater emphasis on team-work and sharing, stronger ties with other disciplines, and a generally more viable discipline.     

三维遥感信息处理系统的设计和应用

利用机载三维遥感技术能够同步获取三维位置和光谱数据的一体化信息。三维遥感信息处理系统利用获取的三维遥感数据生成遥感地学编码图像和DEM (数字表面模型 )。该文阐述了此信息处理系统的数据处理流程和软件构成 ,同时对该系统的各处理模块进行了描述。通过对中关村地区 30 0多km2 的三维遥感信息数据的处理 ,检验了三维遥感信息处理系统的可行性     

无人机遥感在河流岸线资源监管中的应用

以广东省一村级河长监管河段岸线管理范围为研究区域,利用民用轻型无人机采集现场数据,经影像拼接、目标解译和相关资料叠加分析,快速获取了岸线侵占后的界桩、围栏与补种乔灌草等整改措施实施情况,通过整改设计图与遥感判读出的现状结果对比,精准筛查整改措施未落实或整改不到位等监管所需掌握的现存问题区域。研究结果显示：相比传统现场核查,基于无人机遥感方法对于点状目标（如界桩）和线状目标（如围栏）的排查更加高效直观,对面状分布目标（如植被栽植）的复核更具备现场核查所无法比拟的优势,部分不易到达区域的复核的任务也都能较好地解决。无人机遥感作为获取空间数据的重要手段之一,具有机动灵活、影像分辨率高等特点,基于无人机技术的岸线监管可较好解决当前日常监管中存在的问题,对河流岸线监管具有重要意义,应用前景广阔。     

Greenness Index from Phenocams Performs Well in Linking Climatic Factors and Monitoring Grass Phenology in a Temperate Prairie Ecosystem

Near-surface remote sensing (e.g., digital cameras) has played an important role in capturing plant phenological metrics at either a focal or landscape scale. Exploring the relationship of the digital image-based greenness index (e.g., Gcc, green chromatic coordinate) with that derived from satellites is critical for land surface process research. Moreover, our understanding of how well Gcc time series associate with environmental variables at field stations in North American prairies remains limited. This paper investigated the response of grass Gcc to daily environmental factors in 2018, such as soil moisture (temperature), air temperature, and solar radiation. Thereafter, using a derivative-based phenology extraction method, we evaluated the correspondence between key phenological events (mainly including start, end and length of growing season, and date with maximum greenness value) derived from Gcc, MODIS and VIIRS NDVI (EVI) for the period 2015-2018. The results showed that daily Gcc was in good agreement with ground-level environmental variables. Additionally, multivariate regression analysis identified that the grass growth in the study area was mainly affected by soil temperature and solar radiation, but not by air temperature. High frequency Gcc time series can respond immediately to precipitation events. In the same year, the phenological metrics retrieved from digital cameras and multiple satellites are similar, with spring phenology having a larger relative difference. There are distinct divergences between changing rates in the greenup and senescence stages. Gcc also shows a close relationship with growing degree days (GDD) derived from air temperature. This study evaluated the performance of a digital camera for monitoring vegetation phenological metrics and related climatic factors. This research will enable multiscale modeling of plant phenology and grassland resource management of temperate prairie ecosystems.     

Watermarking of digital geospatial datasets: a review of technical,legal and copyright issues

Gathering data accounts for more than 80% of the cost of any GIS project. Fast Internet connections and digital datasets threaten the investments of data producers through data piracy. Outside the GIS community this problem has been known for a long time, and possible solutions exist for digital imagery, formatted text, 3D meshes and so on, showing possible links to typical spatial data. This is largely achieved through embedding hidden information in a dataset without producing perceptible changes in the data, a process known as watermarking. The producer can recover the embedded information on request in order to produce evidence of ownership in a court, so the overall strategy relies on a legal basis rather than technical ones. This paper analyses the state-of-the-art for watermarking protection in digital geographical datasets. Digital imagery is demonstrably a more mature area than geographical information, even with multiple commercial vendors offering watermarking protection. 2D vector and point datasets have received less attention from the research community; however, 3D meshes have been considered by the CAD community and a handful of techniques are available for that case, and they are reviewed here.     

传感器交叉辐射定标综述

 当前遥感应用逐渐从定性向定量化发展的趋势对辐射定标的可靠性提出了更高的要求。传统的场地替代定标法虽然定标精度较高,但是其对场地及测量过程有很严格的要求,能够提供的数据非常有限。交叉定标是国际上新近发展起来的一种无场地定标技术,它的应用弥补了场地定标的不足。对光线匹配交叉定标、光谱匹配交叉定标、基于辐射传输模型交叉定标以及基于瑞利散射交叉定标4种交叉定标方法原理进行了详细介绍,并针对每种方法分析了其适用性。     

Application of time-lapse digital imagery for ground-truth verification of satellite indices in the boreal forests of Alaska

Satellite remote sensing studies of snow cover in high-latitude boreal forests require ground-truth verification based on ground observation networks. In this study, we used time-lapse digital images to precisely detect the extent of snow cover at nine locations in the boreal forests of Alaska, and to demonstrate the relationship of these ground-truth measurements to satellite indices of snow cover. Our results show that normalized difference vegetation indices (NDVIs) and normalized difference water indices (NDWIs) show significant variations at the end and beginning periods of continuous snow cover: the NDVIs on the last days of continuous snow cover ranged from 0.12 to 0.37, and those on the first days of continuous snow cover ranged from 0.16 to 0.38. The normalized difference snow indices (NDSIs) were also positive during periods of continuous snow cover and negative during periods of no snow cover. The NDWIs varied significantly from the beginning to the end of periods of continuous snow cover. This study confirms that continuous snow cover is important for accurate phenological studies using NDVIs in the region of the trans-Alaska camera network. Simple cameras can be effectively utilized in ground-based networks, functioning not only as a ground-truth verification tools for calibrating satellite indices, but also as a source of data to fill data gaps in satellite records.     

A proposed base for a geographical information system for India

Abstract

Attempts have been made by different organizations in India to organize data in order to develop a suitable information system. These attempts were oriented towards specific uses, such as natural resources, data management, thematic mapping and the like. In some attempts software has been developed for some specific purpose. It is not an easy task to develop an information system for a country such as India. Its extent in latitude and longitude is well above average. There are federal and state agencies for the collection of data and the preparation of maps. The geographical information concerning India is available from the following sources: the administrative areas of states, union territories, districts, sub-districts and villages; survey sheets; remote sensing images; aerial photographs; and thematic base maps of the National Atlas and Thematic Mapping Organisation. There are other map series available which have been used for socio-economic mapping. By the end of 1987 the Indian Remote Sensing Satellite will be launched and then remotely-sensed data will be readily available. Considering the geographical bases available in the country, five levels can be identified for developing an information system for India. Some of the thematic maps at 1:1000 000 scale can be used for initiating such a geographical information system.     

GIS-based Analysis of Temporal Evolution of Rural Landscape: A Case Study in Southern Italy

The apparent features of a rural landscape are the final result of the interaction among several natural and anthropic factors. The analysis of a landscape, as well as the identification of its best management strategies, can be improved when useful information about its modifications along a wide time period is available, so as to assess the effect of the transformations that have taken place there. The implementation within a geographic information system (GIS) of geographical information derived from ancient historical maps, combined with modern digital cartography and recent remote sensing images may provide a very powerful tool for a better-informed analysis and targeted decision-making strategies about the most appropriate rural landscape planning. With the purpose to detect the land use changes in a typical rural landscape in the Basilicata Region (Southern Italy), spatial analysis using free and open-source GIS tools, in which data covering a period of about two centuries, from 1829 to 2017, were implemented. This multi-temporal analysis was carried out to investigate the landscape structure transformations through the assessment of land use change and the implementation of a methodology for the identification of areas in which there has been a natural evolution of the rural landscape. Then, using landscape metrics and spatial analysis tools, some areas in which the landscape has naturally evolved without any anthropic intervention during these 188 years have been identified, and changes occurred on the rural landscape were assessed quantitatively.

     

Remote sensing: the use of polarized visible light (PVL) to estimate surface soil moisture

Sunlight is unpolarized; if it is reflected from a soil surface it will become partially polarized. The degree of polarization will be dependent upon the soil surface roughness and moisture content. The study of polarized visible light (PVL) reflectance has developed in the past two decades, from the use of a non-imaging photometer-polarimeter to record the surface roughness of laboratory samples, to the use of a camera and polarizing filter to estimate surface soil moisture in the field. It is demonstrated that PVL recorded at a high phase angle, from up to light aircraft altitudes, can successfully estimate surface soil moisture. This is possible regardless of solar angle, soil albedo or soil slope, over a wide but not umlimited range of surface soil moisture states, but only if surface disturbance and cloud cover are minimized.While PVL cannot, in general, rival currently available techniques for the remote sensing of surface soil moisture it is eminently suitable where an estimate of surface soil moisture is required at low cost for a small area.     

基于蚁群规则挖掘算法的多特征遥感数据分类

蚁群算法作为一种新型的智能优化算法,已经成功应用在许多领域,然而应用蚁群优化算法进行遥感数据处理则是一个新的研究热点。蚁群规则挖掘算法是基于分类规则挖掘进行分类,能够处理多特征的数据。因此,论文将蚁群规则挖掘算法应用到多特征遥感数据分类处理中,并采用北京地区的Landsat TM和 Envisat ASAR数据作为实验数据,对选择的遥感数据进行了多特征分类实验。实验结果分别与最大似然分类法、C4.5方法进行对比,分析表明:1)蚁群规则挖掘算法是一种无参数分类的智能方法,具有很好的鲁棒性,2)能够挖掘较简单的分类规则;3)能够充分利用多源遥感数据等。它可以充分利用多特征数据进行土地覆盖分类,从而能够提高分类的效率。     

遥感技术在洪涝灾害防治体系建设中的应用

本文综述了遥感技术在洪涝灾害防治体系建设中的应用 ,包括洪涝灾害背景数据的建设和更新、洪涝灾害承灾体的识别和信息提取、洪涝灾害相关模型计算以及灾害监测、减灾救灾应急系统等方面 ,并对目前应用中存在的主要问题和发展方向进行了探讨.     

Radiometric field work and remote sensing using satellite data

There has been a marked growth in the number of spacecraft and airborne sensors since 1972, the date of the launching of the first satellite developed to monitor Earth's resources (LANDSAT). As a consequence, geographers interested in remote Sensing in New Zealand have had a widening range of data sources available to them. Geographers first expressed interest in monitoring ground cover using I.ANDSAT series data, but interest in remote sensing data has widened to include work on marine environments, structural geology, urban areas and soil survey. As Curran (1984) indicates, the development and use of thermal and microwave sensors is likely to rapidly extend the uses of remote sensing. In New Zealand, the growth in the number of stored data bases plus the increased sophistication of digital computer analysis (both dominated by the national centre, The Remote Sensing Section. DS1R) is encouraging. However, it is a matter of some concern that there does not seem to be a parallel growth in the radiometric field work required to reconcile sensor data with field information. This note examines some of the reasons which have led to this problem, stresses the importance of radiometric ground truth and describes a method of collecting radiometric data which is in operation at the University of Waikato.     

沙漠化遥感数字图象处理试验研究

国际合作项目大沁塔拉地区沙漠化环境遥感监测研究课题, 使用了陆地卫星MSS和TM的CCT磁带资料。计算机遥感数字图象处理工作是在西德进行的。处理结果经两国科学工作者在野外实地验证, 一致认为, 效果较好, 符合沙漠化专业要素特征, 有利于沙漠化发展现状图和动态图的编制。