基于数字地图制图技术的地图色彩语言艺术化方法

艺术性是评价地图质量的重要标准。数字制图技术为提高地图艺术性创造了十分有利的条件,但是如果不能充分合理地利用这种良好的技术条件,仍然不能编制出具有较高艺术性的地图。首先阐述了地图色彩语言艺术化的目标及对技术条件的要求;然后从审美化、形象化、情感化、技巧化四个艺术化的目标论述了利用数字制图技术提高地图色彩语言艺术性的方法。     

A new map of the Mitdluagkat glacier—a preliminary report

Hasholt, Bent: A new map of the Mitdluagkat glacier—a preliminary report. Geografisk Tidsskrift 87: 19–21, Copenhagen June 1987.

A new map covering the whole Mitdluagkat Glacier has been elaborated. The map is based on air photos from Geodetic Institute in scale 1:150,000 taken July 30, 1981. The scale of the new map is 1:20,000 with 10-m contour intervals. Preliminary field tests indicate that the map is so accurate that it might be used for comparative studies of long-term variations in mass balance of the glacier.     

Asian Transboundary Aquifers Inventory and Mapping

Transboundary aquifer (TBA) is an aquifer system that exists in more than one state. As an important component of the groundwater system, proper management and rational utilization in trans-boundary aquifers are significantly important for promoting sustainable development and good-neighbor relationships. The Transboundary Aquifers will not implicate by the country’s political boundary as it follows the natural boundary lines. Within the frame work of the UNESCO''s International Hydrological Programme (IHP-VI & VII) activities for the International Shared Aquifer Resource Management (ISARM), the inventory on TBA in Asia both preliminary and detail has accomplished. Those TBAs are classified in to two types: regional and local grade. A of Asian Transboundary Aquifers Map has advanced. The updated map provides the situation of the regional TBAs identify as the actual shape. Countries with the TBAs should strengthen cooperation for coordination and joint management of groundwater resources in order to achieve sustainable use     

城区基础地理信息管理系统建设的实践--以潍坊市为例

近年来,随着全国地理信息产业的高速发展,国土部门主持开展的基本比例尺基础地理信息数据采集及数据库建设工作在全国各地相继展开。结合潍坊市实际,对城区基础地理信息数据库建设进行了有益实践,从地理信息数据获取、处理,到数据库建设,总结提出了可行的技术路线和方法,具有实用与借鉴价值。城区基础地理信息数据库的建设,对于提升城市基础地理信息的管理水平,为城市规划、建设与管理提供信息保障服务,可以取得良好的经济与社会效益。     

测绘与地理信息市场政策环境研究(专题九研究报告之二)

从测绘与地理信息行业自身的特点和现状出发,探讨了在市场经济环境下如何生存与发展．目前测绘市场的竞争环境,人们对地理信息产品的需求,以及从长远和进入国际市场的角度考虑．规范测绘市场、建立测绘监理制度和注册测量师的必要性。     

Combining Lidar Elevation Data and IKONOS Multispectral Imagery for Coastal Classification Mapping

This article studies the effect of airborne lidar (surface) elevation data on the classification of multispectral IKONOS images over a coastal area. The lidar data and IKONOS images are treated as independent multiple bands to conduct the classification. To do so, the lidar elevation data is first resampled to the same ground spacing interval and stretched to the same radiometric range as the IKONOS images. An unsupervised classification based on the ISODATA algorithm is then used to determine a class schema of six classes: road, water, marsh, roof, tree, and sand. Training sites and checking sites are selected over the lidar-IKONOS merged data set for the subsequent supervised classification and quality evaluation. The complete confusion matrices and average quality indices are presented to assess and compare the classification results. It is shown that the inclusion of the lidar elevation data benefits the separation of classes that have similar spectral characteristics, such as roof and road, water and marsh. The overall classification errors, especially the false positive errors, are reduced by up to 50%. Moreover, by using the lidar elevation data, the classification results show more realistic and homogeneous distribution of geographic features. This property will benefit the subsequent vectorization of the classification maps and the integration of the vector data into a geographical information system.     

Why Web GIS May Not Be Enough: A Case Study with the Virtual Research Vessel

During several decades of investigation, the East Pacific Rise seafloor-spreading center at 9°-10°N has been explored by marine geologists, geophysicists, chemists, and biologists, and has emerged as one of the best studied sections of the global midocean ridge. It is an example of a region for which there is now a great wealth of observational data, results, and data-driven theoretical studies. However, these have yet to be fully utilized, either by research scientists or educators. While the situation is improving, a large amount of data, results, and related theoretical models still exist either in an inert, noninteractive form (e.g., journal publications) or as unlinked and currently incompatible computer data or algorithms. Presented here is the prototype of a computational environment and toolset, called the Virtual Research Vessel, to improve the situation by providing marine scientists and educators with simultaneous access to data, maps, and numerical models. While infrastructure is desired and needed for ready access to data and the resulting maps via web GIS in order to link disparate data sets (data to data), it is argued that data must also be linked to models for better exploration of new relations between observables, refinement of numerical simulations, and the quantitative evaluation of scientific hypotheses. For widespread data access, web GIS is therefore only a preliminary step rather than a final solution, and the ongoing implementation of the Virtual Research Vessel (scheduled for final completion in 2004-2005) is a case study for the midocean ridge community to test the effectiveness of moving beyond the data-to-data mode towards data-to-models and data-to-interpretation.     

Determination of the 3D structure of an earthflow by geophysical methods: The case of Super Sauze, in the French southern Alps

In order to evaluate the risk associated by an earthflow to abruptly evolve into a torrential flow, the knowledge of its internal structure is necessary. Geotechnical methods are important to reach this goal. However, because of the rough topography associated with earthflows, their surface heterogeneities, and the spatial variations of the thickness of the potentially moving mass, non-intrusive geophysical methods offer a very useful tool that complements traditional geotechnical methods. We report the results of a comprehensive study covering a 150 m by 200 m area of the Super Sauze earthflow. This earthflow developed in black marls in the southern French Alps. Shallow electrical conductivity investigations, derived using low frequency domain electromagnetics, maps hidden gullies and crests and lateral variations of the clay and the water content within the first 5 m below the ground surface. Electrical resistivity tomography allows to extrapolate this information down to 10 m below the ground surface along selected transects. The vertical structure of the earthflow, down to the substratum, is defined precisely thanks to joint inversion of DC and TDEM vertical soundings along one profile: the flowing upper layer and the position of the substratum are clearly evidenced. Combining this geophysical datasets with geotechnical tests and drill holes, we provide an estimate of both the location and the volume of the potentially most dangerous areas of the earthflow.     

Improved edge detection mapping through stacking and integration: a case study in the Bathurst Mining Camp

Airborne geophysical surveys provide spatially continuous regional data coverage, which directly reflects subsurface petrophysical differences and thus the underlying geology. A modern geologic mapping exercise requires the fusion of this information to complement what is typically limited regional outcrop. Often, interpretation of the geophysical data in a geological context is done qualitatively using total field and derivative maps. With a qualitative approach, the resulting map product may reflect the interpreter's bias. Source edge detection provides a quantitative means to map lateral physical property changes in potential and non‐potential field data. There are a number of Source edge detection algorithms, all of which apply a transformation to convert local signal inflections associated with source edges into local maxima. As a consequence of differences in their computation, the various algorithms generate slightly different results for any given source depth, geometry, contrast, and noise levels. To enhance the viability of any detected edge, it is recommended that one combines the output of several Source edge detection algorithms. Here we introduce a simple data compilation method, deemed edge stacking, which improves the interpretable product of Source edge detection through direct gridding, grid addition, and amplitude thresholding. In two examples, i.e., a synthetic example and a real‐world example from the Bathurst Mining Camp, New Brunswick, Canada, a number of transformation algorithms are applied to gridded geophysical data sets and the resulting Source edge detection solutions combined. Edge stacking combines the benefits and nuances of each Source edge detection algorithm; coincident or overlapping and laterally continuous solutions are considered more indicative of a true edge, whereas isolated points are taken as being indicative of random noise or false solutions. When additional data types are available, as in our example, they may also be integrated to create a more complete geologic model. The effectiveness of this method is limited only by the resolution of each survey data set and the necessity of lateral physical property contrasts. The end product aims at creating a petrophysical contact map, which, when integrated with known lithological outcrop information, can be led to an improved geological map.     

多光谱相机基于灰阶靶标的在轨绝对辐射定标

多光谱相机在轨绝对辐射定标是其遥感数据定量化应用的关键环节。高空间分辨率多光谱相机基于大面积灰阶靶标的在轨辐射定标, 以灰阶靶标BRDF、漫射/总辐射比和大气光学厚度等参数的地面测量为主, 通过目标反射辐射与大气程辐射、周围环境辐射的分离, 消除了对气溶胶散射的假设, 简化了定标流程, 突破了基于大面积均匀场定标受到的地理位置和天气状态等条件限制, 该方法有望实现高空间分辨率多光谱相机全动态范围内的高频次、高精度业务化在轨辐射定标。不确定度分析表明, 目前该辐射定标方法可实现4.7%的不确定度, 将来有望提高到3%—4%的水平。对天绘一号多光谱相机进行了基于大面积灰阶靶标的定标试验, 通过两次过顶时刻地面总辐照度变化的比较及靶标观测值的回归分析, 初步判断两次定标时间内多光谱相机波段3的性能发生了变化。