SOVIET GEODESISTS IN THE CENTRAL ARCTIC

The work of a recent Soviet geodetic surveying expedition to the Central Arctic and the Barents Sea off Franz Josef Land is described, with an emphasis on gravimetric surveying and determination of gravimetric control points at the North Pole and at two drifting polar research stations. In addition, glacier fields of Alexander Land (Franz Josef Land) were mapped and keys for their interpretation on space imagery identified. Translated from: Geodeziya i kartografiya, 1988, No. 3, pp. 9-12.     

Northern marine transportation corridors: Creation and analysis of northern marine traffic routes in Canadian waters

The concept of the Northern Marine Transportation Corridors (NMTC) initiative was developed under the Government of Canada World‐Class Tanker Safety System Initiative (WCTSS). The NMTC is an interdepartmental Arctic initiative within the Department of Fisheries and Oceans Canada (DFO), through the Canadian Coast Guard (CCG) and the Canadian Hydrographic Service (CHS), in collaboration with Transport Canada (TC). The NMTC initiative was developed to strengthen the safety of marine navigation in the Arctic, and to offer an efficient planning guide for present and future Arctic investments. Transportation corridors identified through this initiative will provide the Government of Canada the framework needed to better prioritize and deliver on its programs and services, including: nautical charts and products; aids to navigation; icebreaking services; and marine safety regulations. The corridors were generated and analyzed with a Geographic Information System (GIS) using two main data sources: the Automated Identification System (AIS) and CHS's nautical charts and publications. The geographic extent of the NMTC is defined as the Northern Canada Vessel Traffic Service Zone (NORDREG Zone) and the Mackenzie River. With close to 4 million km² of water in the Arctic and 162,000 km of coastline, surveying the Arctic to modern standards represents an enormous challenge to CHS. By adopting a corridor‐based approach, CHS and other government programs can prioritize their efforts on 12% of the Canadian Arctic waters. CHS currently has 32% of the NMTC adequately surveyed, with an additional 3% surveyed to modern standards.     

北极臭氧年际变化特征及其与极涡的关系

利用风云三号卫星搭载的紫外臭氧总量探测仪(TOU)和国际同类卫星的臭氧总量数据对1979年—2011年北半球春季臭氧特征进行了分析,发现北极臭氧年际变化显著,它与平流层温度变化一致(相关系数为0.75)。北极臭氧损耗异常强弱年的月均和日变化特征有明显差异,春季北极臭氧损耗强年有明显的化学损耗过程(1997年和2011年),而弱年化学作用影响不明显(1999年和2010年)。损耗弱年的日变化型在不同年份特征不同,它的臭氧变化可能更多受天气过程的影响。综合分析北极涛动、极涡和平流层温度等大气环流背景场的变化,表明春季北极臭氧损耗强弱受大气环流变化影响。北极涛动指数正位相,极涡偏强偏冷,北极臭氧损耗异常偏高。北极涛动指数负位相,极涡偏弱偏暖,北极臭氧损耗异常偏低。     

利用航空立体像对确定岩层产状的计算机方法

本文介绍了一种利用PC-1500袖珍计算机根据航空立体像对计算岩层、构造产状的新方法。 该方法使用简单、快速,不受产状大小的影响。计算结果的精度均优于以往的各种方法。能够用 于系统的产状量测工作,为图像的目视解译提供了更多的信息。     

南北极地图集的设计与特点

作为中国第一部反映南北极地区地理环境和科考情况的地图集《南北极地图集》,该图集特殊的地理条件决定了其在编绘方式上与其他图集不同,从图集的内容设计、整饰和色彩设计、以及统一协调性研究3个方面入手,重点介绍图集设计中各方面的特色,总结图集编制的技术路线,为同类地图集的编绘提供参考。     

THE CANADA-UNITED STATES BOUNDARY COMMISSION

Abstract

The International Boundary Commission is a body which has been created by treaty between Canada and the United States for the purpose of surveying, mapping, and marking the international boundary between the two countries and for subsequently maintaining that boundary in a state of effective demarcation. The Commission consists of two Commissioners and their staffs. One Commissioner is appointed by His Britannic Majesty upon the recommendation of the government of Canada, the other is appointed by the President of the United States. Each government pays the salaries of its own officers, but the other expenses are borne equally by the two governments. It should be noted that the International Boundary Commission is a body quite distinct and separate from the International Joint Commission, with which it is sometimes confused. The functions of these two Commissions do not overlap or duplicate each other in any way. The International Joint Commission has jurisdiction over all cases involving the use, obstruction, or diversion of boundary waters, and, in addition, when requested by the government of either Canada or of the United States, examines and reports upon such other questions of difference as may arise in the vicinity of the boundary, involving the rights, obligations, or interests of either country in relation to the other or to its inhabitants. The consideration of such questions does not come within the purview of the International Boundary Commission. On the other hand, to the latter body pertains exclusively the work of surveying, mapping, and marking the boundary, and the location of any point on the boundary in connection with any question that may arise between the two governments.     

测量机器人系统构成与精度研究

对测量机器人的特点进行了详细分析 ,对其自动化的工作原理进行了研究 ,其核心技术是用CCD摄像机获取目标图像 ,用计算机软件对数字图像进行分析和匹配 ,提取所需要的特征点 ,再配以精密马达伺服机构控制经纬仪系统的水平和垂直旋转 ,从而实现观测自动化。同时还简要介绍了与测量机器人配套使用的软件 ,并给出了试验结果。     

超站式集成测绘系统STGPS的研究

介绍了超站式集成测绘系统STGPS的研究思想、研究目标、系统构成和功能;讨论了坐标转换和测绘基本服务问题;提出了无需作加密控制的即用即测作业模式。     

SPIRIT. SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies during the fourth International Polar Year (2007–2009)

Monitoring the evolution of polar glaciers, ice caps and ice streams is of utmost importance because they constitute a good indicator of global climate change and contribute significantly to ongoing sea level rise. Accurate topographic surveys are particularly relevant as they reflect the geometric evolution of ice masses. Unfortunately, the precision and/or spatial coverage of current satellite missions (radar altimetry, ICESat) or field surveys are generally insufficient. Improving our knowledge of the topography of Polar Regions is the goal of the SPIRIT (SPOT 5 stereoscopic survey of Polar Ice: Reference Images and Topographies) international polar year (IPY) project. SPIRIT will allow (1) the acquisition of a large archive of SPOT 5 stereoscopic images covering most polar ice masses and, (2) the delivery of digital terrain models (DTM) to the scientific community.Here, we present the architecture of this project and the coverage achieved over northern and southern polar areas during the first year of IPY (July 2007 to April 2008). We also provide the first accuracy assessments of the SPIRIT DTMs. Over Jakobshavn Isbrae (West Greenland), SPIRIT elevations are within ±6 m of ICESat elevations for 90% of the data. Some comparisons with ICESat profiles over Devon ice cap (Canada), St Elias Mountains (Alaska) and west Svalbard confirm the good overall quality of the SPIRIT DTMs although large errors are observed in the flat accumulation area of Devon ice cap. We then demonstrate the potential of SPIRIT DTMs for mapping glacier elevation changes. The comparison of summer-2007 SPIRIT DTMs with October-2003 ICESat profiles shows that the thinning of Jakobshavn Isbrae (by 30–40 m in 4 years) is restricted to the fast glacier trunk. The thinning of the coastal part of the ice stream (by over 100 m) and the retreat of its calving front (by up to 10 km) are clearly depicted by comparing the SPIRIT DTM to an ASTER April-2003 DTM.     

2000—2015年北极夏季反照率变化及其与海冰密集度的关系

作为影响极区热平衡的关键因素,北极反照率会对北极气候与环境变化产生重要影响。采用CLARA-A2-SAL(The CM SAF Cloud,Albedo and Radiation)反照率产品分析2000—2015年北极夏季反照率月尺度和年尺度的时空变化,并探索北极反照率与海冰密集度的关系。结果表明,近15年间北极夏季反照率降幅达到12.20%,8月反照率下降趋势最显著,每10年减少0.040;随着海冰的融化,北极夏季反照率发生由高到低的变化;北极中央密集冰区与周边海域的反照率变化呈现出显著的空间差异性;北极反照率与海冰密集度呈稳定的正相关。研究北极反照率的时空变化及其影响因素可为解释海冰变化成因、预测北极海冰变化趋势提供参考。     

RECONNAISSANCE MAPPING FROM TRIMETROGON AIR PHOTOGRAPHS IN THE ANGLO-EGYPTIAN SUDAN

Abstract

Trimetrogon air surveys have been used extensively in the United States and Canada but seem to have had less favour on this side of the Atlantic in spite of the fact that large areas over here were photographed in this way during the last war. The Sudan is a very large country, but not a rich one; and up to the present it has not been able to undertake its own aerial photography. The gift of a very large number of American trimetrogon photographs covering half the country was therefore very welcome, and it seemed worth our while to see what could be done with them in spite of the known disadvantages of this type of photography for anything but small scale mapping. The methods of planimetric mapping from these photographs developed in the United States were expressly designed to be as simple as possible and to be capable of division into a number of easy tasks which could be performed by any educated person after a short course of training. Nevertheless we felt that they could be simplified a great deal more if the problem was approached from a different angle, particularly in view of the very high standard of flying which was apparent in the photographs covering the Sudan.     

数字正射影像结合LiDAR数据在山区测绘中的应用

随着信息化社会的到来,现代水利测绘已经由传统测绘向信息化测绘发展,无人机技术应用于测绘行业推进了信息化测绘进程。本文探讨了如何有效利用无人机技术解决测绘领域在山区遇到的问题。固定翼无人机能及时获取地面数字正射影像数据,捕获裸露地面的平面和高程,但是无法获取植被覆盖下的地表高程信息,因此,本文通过机载激光雷达获取植被覆盖下的LiDAR点云数据;将二者数据相结合,再通过EPS软件生成三维地表模型,可以快速获取任何测区地物和地形数据,不仅提高了工作效率,还降低了外业劳动强度。     

瞬时极坐标与时号改正的自动解算

天文测量数据处理软件在解算经纬度、方位角和人仪差时,需要预先计算出瞬时极坐标值和测前测后时号改正值。本文使用天文数据处理软件的准备文件数据直接进行极坐标和时号改正的解算,对传统内业解算步骤进行编程,减少内业计算的人工干预和数据处理环节。实验与分析表明,自动解算方法能够显著提高作业效率,减少计算的人为误差。     

Soil survey of command area for planning of water management: A case study of an area in Hardoi district,U.P.

Development of irrigation potential for increasing agricultural production is the main aim of Command Area Development. This involves interaction amongst various factors; the soil, the crop, the climate, the topograpny and others. Water management in Command Area requires careful planning, based upon adequate data regarding soils, land use and topography. It is essential to make the best possible use of the available water without creating waterlogging, salinity and alkalinity problems in the command area. The use of aerial photographs is a well recognized expedient, convenient and economical method of data collection, which appreciably suits the requirement of the survey of Command Areas. As large areas have to be surveyed for data collection, the best way to accomplish this is by taking up survey of command area in different levels: reconnaissance, semi-detailed and detailed. The reconnaissance and semi-detailed survey would enable us to identify problem areas. Detailed survey are needed in these areas for taking up reclamation measures. A case study of soil survey carried out in the Sharda Sahayak Command Area of a part of Hardoi District is given as an example to illustrate the use of aerial photographs for planning of water management practices.     

THE APPLICATION OF RADAR TO SURVEYING

Abstract

Radar can be applied to surveying for precise measuren1ent of long lines, and as a navigational aid and position-fixing device for an aircraft performing a photographic survey. Trials of the radar method have recently been carried out in Australia using a modified “Shoran” equipment. The results of a large number of radar measurements of six distances, varying from 160 to 310 miles in length, indicate that an accuracy of 7 parts in 10⁵ can be achieved. Equipment errors constitute the immediate limit to accuracy, but reasonable modifications would yield a figure of 2 parts in 10⁵. Radar measurements can be completed in a fraction of the time required by normal ground survey methods, since a measurement of upwards of a hundred miles is made in a single step.

As an aid to photographic surveying a straight-line track indicator actuated by data from the “Shoran” equipment has been designed and flight tested. Its performance enabled a pilot taking aerial photographs to keep the aircraft to within an average departure of less than 0.02 mile from any desired straight-line flight path.     

浅析数字龙江地理空间框架建设一期工程作业中的若干关键问题

在开展数字龙江地理空间框架建设一期工程——黑河测区工作中,利用航空和卫星影像进行1∶10 000地形图的测绘与更新,本文针对具体工作中的一些关键及重要问题进行了阐述。     

Review of Doppler satellite positioning in Canada

Canada has recently faced two geodetic problems. Existing control on land must be rapidly upraged for resource development and for the coming redefinition of North American networks. Geodetic methods of managing territorial and lease boundaries in the offshore region are required. A series of developments in Doppler Satellite techniques begun in 1968 have contributed to the solution of both these problems. Today these developments have resulted in a Canadian-made receiver, permanent Canadian tracking stations, a primary geodetic network of about 200 Doppler points, major Doppler processing software systems, and the routine use of Doppler points, major Doppler processing software systems, and the routine use of Doppler positioning for land surveying, drill rig positioning and precise navigation. The accuracy of Doppler positioning has been improved from 100 m in 1968 to better than 1 m in 1975. These developments have applications in other nations than Canada.     

海潮对高精度GPS网的影响初探

本文叙述了海洋负荷潮改正的基本原理，结合算例分析了海潮对GPS网的影响，结果显示：对于近海地区较短时段的GPS观测，考虑海潮负荷改正可以明显地提高解算精度，特别对改善高程方向的精度贡献明显。影响可达数厘米，这种影响的量级对水平方向不明显；对于远离海洋地区，海潮负荷改正的影响已不明显，可以不与考虑。     

基于NOAA/AVHRR数据的北极反照率反演及其变化研究

极地海冰反照率直接影响极区的热收支,反照率的变化对地气系统热量收支平衡及气候变化等的研究具有重要意义。本文采用由美国国家海洋与大气管理局NOAA (National Oceanic and Atmospheric Administration)发射的NOAA卫星携带的先进的甚高分辨率辐射仪AVHRR (Advanced Very High Resolution Radiometer) Level-1B (L1B) 数据,经宽带反射率转换、各向异性校正、大气订正、云检测等处理,得到4 km宽带晴空地表反照率产品。将AVHRR反照率与北冰洋地表热收支SHEBA (Surface Heat Budget of the Arctic Ocean)实验数据进行印证,印证结果显示在冰雪冻结期二者平均偏差为-0.07,标准偏差为0.05。本文处理了2008年—2010年的AVHRR数据,结合第4次北极科学考察现场观测数据研究了北极冰面月平均反照率的变化,从降雪和冰脊两个方面分析了反照率的变化,结果显示反照率在冰雪融化过程中变化约为0.3,变化较大且较为迅速,表面粗糙的多年冰海域和较为平滑的一年冰海域的反照率在雪融化时期变化约为0.2且变化相对缓慢。研究结果表明,由冰雪融化引起的反照率变化较为快速且幅度较大,是引起北极反照率变化的主导因素。     

补偿最小二乘估计在重力测量中的应用

在测量数据处理中,系统误差总是作为有害成分设法予以消除或补偿,但随着测绘科技的进一步发展,也有一些研究者将系统误差或非参数信号看作非随机变量,利用补偿最小二乘等方法,提取系统误差,从而对它有更多地了解,以满足高精度测量的需要。而本文在系统误差为随机变量的情况下,利用补偿最小二乘法研究半参数模型。得到了参数及非参数的估计;接着,讨论了估计量的若干统计特性;最后,用补偿最小二乘法研究重力测量中的重力异常问题,得到了重力异常的估计值,相同于用最小二乘配置法所得的结果,从而说明本文方法的有效性。