Arno Peters—The Man,The Map,The Message

Abstract

At the present time, relatively few cartographic staff are directly involved in automation, and we are still in the phase mainly of research and development. Nevertheless, the educational implications of automation are considerable, as major changes in the systems of map production are bound to affect the content and requirements of educational programmes.     

Continental mass change from GRACE over 2002–2011 and its impact on sea level

Present-day continental mass variation as observed by space gravimetry reveals secular mass decline and accumulation. Whereas the former contributes to sea-level rise, the latter results in sea-level fall. As such, consideration of mass accumulation (rather than focussing solely on mass loss) is important for reliable overall estimates of sea-level change. Using data from the Gravity Recovery And Climate Experiment satellite mission, we quantify mass-change trends in 19 continental areas that exhibit a dominant signal. The integrated mass change within these regions is representative of the variation over the whole land areas. During the integer 9-year period of May 2002 to April 2011, GIA-adjusted mass gain and mass loss in these areas contributed, on average, to ?(0.7 ± 0.4) mm/year of sea-level fall and + (1.8 ± 0.2) mm/year of sea-level rise; the net effect was + (1.1 ± 0.6) mm/year. Ice melting over Greenland, Iceland, Svalbard, the Canadian Arctic archipelago, Antarctica, Alaska and Patagonia was responsible for + (1.4±0.2) mm/year of the total balance. Hence, land-water mass accumulation compensated about 20 % of the impact of ice-melt water influx to the oceans. In order to assess the impact of geocentre motion, we converted geocentre coordinates derived from satellite laser ranging (SLR) to degree-one geopotential coefficients. We found geocentre motion to introduce small biases to mass-change and sea-level change estimates; its overall effect is + (0.1 ± 0.1) mm/year. This value, however, should be taken with care owing to questionable reliability of secular trends in SLR-derived geocentre coordinates.     

王府井新华书店图书销量排行榜(2002年7月～9月)

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西单图书大厦图书销量排行榜(2002年7月～9月)

SB参考地图朋新北京地图册甲及周边旅游休闲指中了地【司机行车地图旦纪北了生活地图理参考回册（成人高考卞国旅浓出行地图新编实用中国地图中国自助游最新北京详图 ;prprprprprpArpA 9655555858 卜84000——工9 二——H 山 、 日 出 V—儿 出,MoprtXtertAsXirpwtw的\co——33 出 口0W;ptortoptreq＄?f toAFI＆7;Nrppory 蠢注中国地图出版地质出版社质出版衬中国地图出版社中国地图出版社中国地图出版社山东地图出版社中国地图出版社东地图出版湖南地图出版社 rtotwop——;;;！＆53 口 旧 旧ig 门 旧u 以…     

国土资源综合统计半年报(2002年1月～6月)

根据全国31个省、自治区、直辖市国土资源厅(局)、新疆生产建设兵团国土资源局及国土资源部有关司局上报的国土资源综合统计半年报。汇总整理出全国2002年1月～6月国土资源行政管理情况如下: 一、审批用地情况 2002年上半年全国共申报建设用地面积73438.46公     

Report on the ISPRS Journal of Photogrammetry and Remote Sensing (PRS) for the period 1996–2000

This report was presented by the author, as Editor-in-Chief (EIC) of PRS, to the General Assembly of the Delegates of the ISPRS Members during the 19th ISPRS Congress, Amsterdam, 16–23 July 2000. Since it summarises in quite some detail many new developments since the last Congress that are of interest not only to ISPRS in general, but also to authors and readers, a slightly modified version of this report is published here.     

THE GEODETIC LEVELLING OF CEYLON (1926–1929)

Abstract

The Net.—The total length of the lines of the level-net is roughly 2400 miles. The net comprises 27 circuits with perimeters varying between 74 and 268 miles, and is generally closer in the wet zone than in the sparsely populated and undeveloped dry zones. In 12 circuits there are differences of level exceeding 1000 feet. The highest point reached in the net is 6572 feet, and a branch line runs from Nuwara Eliya to the summit of Pidurutalagala, the highest mountain in the island (8282 feet).     

Prioritization of Sub-watersheds in Khanapara–Bornihat Area of Assam–Meghalaya (India) Based on Land Use and Slope Analysis Using Remote Sensing and GIS

Improper utilization of natural resources without any conservation work is the prime cause of the watershed deterioration. Fast developmental activities and population pressure in the hills of Khanapara?CBornihat area near Guwahati city (about 10?km east of Guwahati) results rapid alteration of the land use/land cover in the recent times. This also causes the growth of land use over the unsuitable topography. As a result, there is a general degradation of the natural resources within the area. So, urgent measures have to be adopted to take up the conservation measure for the management of natural resources. Watershed wise conservation is considered to be the most acceptable and convenient approach. In the context of watershed management, watershed prioritization gained importance in natural resource management. The present study makes an attempt to prioritize the sub-watersheds for adopting the conservation measure. The prioritization is based on land use and slope analysis using Remote Sensing and GIS techniques in Khanapara?CBornihat area of Assam and Meghalaya state (India). The study area of 323.17?sq. km is divided into three 5th order, four 4th order and two 3rd order sub-watersheds. Land use/Land cover change analysis of the sub-watersheds has been carried out using multi temporal data of SOI toposheets of 1972 and IRS LISS III imagery of 2006. The study shows the significance changes in land use pattern especially in settlement and forest lands from 1972 to 2006. Slope map of the sub-watersheds prepared from the contour values in the toposheets show the wide variation of slope in the area ranging from 0° to 87°. Based on the extent/nature of land use/land cover changes over time and land use/land cover??slope relationship analysis, the sub-watersheds are classified into three categories as high, medium and low in terms of priority for conservation and management of natural resources.     

Comment on Sjöberg (2006) “The topographic bias by analytical continuation in physical geodesy” J Geod 81(5):345–350

The analytical, or harmonic, downward continuation of the external gravity potential into the topographic masses gives rise to a bias, which is called the analytical (downward) continuation (ADC) bias (Ågren in J Geod 78:314–332, 2004a) or the topographic bias (Sjöberg in J Geod, 2006). In Sjöberg (J Geod, 2006), a proof is presented that this bias is exactly equal to a simple two-term expression, which depends only on the topographic height and density in the evaluation point P. The expression is simple and inexpensive to evaluate. In this paper, we wish to question the validity of the expression given in Sjöberg (J Geod, 2006) for realistic terrains. The topographic bias is commonly defined as the difference between the true (internal) and the analytically downward continued external geopotential, evaluated at sea level. Typically both are evaluated as external or internal spherical harmonic (SH) expansions, which may however not always converge. If they do converge, they have been well known in the literature (e.g., Ågren (J Geod 78:314–332, 2004a), Wang (J Geod 71:70–82, 1997)) to produce a bias that contains additional terms over and beyond the simple expression. Below we analyze the additional terms that arise when applying the method to realistic terrains. Also, for realistic terrains, analytical downward continuation may not even be strictly possible. In practice, for discrete data sets, it is always possible, but then, an implicit smoothing of the terrain, or terrain potential, always takes place.     

《四川测绘》2002年(第25卷)总目次

(一 )基于Ｃｌｉｅｎｔ/Ｓｅｒｖｅｒ结构的土地信息系统的设计与研制范东明 ,张献州 ,等 ( 3)………………………………基于ＶＲＭＬ三维动态虚拟现实场景的实现王艳慧 ( 8)………………………………………………………一种地形三维数据快速采集系统的研究杨旭 ,翟翊 ( 1 2 )……………………………………………………石化厂管线信息系统的空间分析初步研究张军 ,顾新 ( 1 5 )…………………………………………………地理信息系统 (ＧＩＳ)软件技术郑江玲 ( 1 8)……………………………………………………………………虚拟现实地理信息系统…     

Interannual variability of low-degree gravitational change, 1980–2002

Time variations in the Earths gravity field at periods longer than 1 year, for degree-two spherical harmonics, C₂₁, S₂₁, and C₂₀, are estimated from accurately measured Earth rotational variations. These are compared with predictions of atmospheric, oceanic, and hydrologic models, and with independent satellite laser ranging (SLR) results. There is remarkably good agreement between Earth rotation and model predictions of C₂₁ and S₂₁ over a 22-year period. After decadal signals are removed, Earth-rotation-derived interannual C₂₀ variations are dominated by a strong oscillation of period about 5.6 years, probably due to uncertainties in wind and ocean current estimates. The model-predicted C₂₀ agrees reasonably well with SLR observations during the 22-year period, with the exception of the recent anomaly since 1997/1998.     

THE ART OF ORIGINAL CIRCULAR DIVIDING (1650–1850)

Abstract

The problem of dividing the circle into equal parts has occupied the minds of astronomers and instrument makers from the earliest times, but little is known of the methods adopted by such renowned observers as Hevelius or Tycho Brahe, who are said to have divided their own instruments (I). It is possible, however, to trace the various steps by which progress was made and to appreciate the urgent need that was felt, particularly throughout the eighteenth century, for improvement in the accuracy of astronomical instruments, if only to satisfy the increasing demands for navigational charts and for the means of determining the position of a ship at sea.     

Monitoring Urban Landscape Dynamics Over Delhi (India) Using Remote Sensing (1998–2011) Inputs

Urbanization is increasingly becoming a widespread phenomenon at all scales of development around the globe. Be it developing or developed nations, all are witnessing urbanization at very high pace. In order to study its impacts, various methodologies and techniques are being implemented to measure growth of urban extents over spatial and temporal domains. But urbanization being a very dynamic phenomenon has been facing ambiguities regarding methods to study its dynamism. This paper aims at quantifying urban expansion in Delhi, the capital city of India. The process has been studied using urban land cover pattern derived from Landsat TM/ETM satellite data for two decades (1998–2011). These maps show that built-up increased by 417 ha in first time period (1998–2003) and 6,633 ha during next period (2003–2011) of study. For quantification of metrics for urban expansion, the Urban Landscape Analysis Tool (ULAT) was employed. Land cover mapping was done with accuracy of 92.67 %, 93.3 % and 96 % respectively for years 1998, 2003 and 2011. Three major land covers classes mapped are; (i) built-up, (ii) water and (iii) other or non-built-up. The maps were then utilized to extract degree of urbanization based on spatial density of built-up area consisting of seven classes, (i) Urban built-up, (ii) Suburban built-up,(iii) Rural built-up, (iv) Urbanized open land, (v) Captured open land, (vi) Rural open land and (vii) Water. These classes were demarcated based on the urbanness of cells. Similarly urban footprint maps were generated. The two time maps were compared to qualitatively and quantitatively capture the dynamics of urban expansion in the city. Along with urbanized area and urban footprint maps, the new development areas during the study time periods were also identified. The new development areas consisted of three major categories of developments, (i) infill, (ii) extension and (iii) leapfrog.     

Effect of linear and non-linear mixing on hyper-spectral signatures of snow in the optical region (350–2500 nm)

Study of hyper-spectral behaviour of snow is important to interpret, analyse and validate optical remote sensing observations. To map and understand response of snow-mixed pixels in RS data, field experiments were conducted for linear mixing of external materials (i.e. Vegetation, Soil) with snow, using spectral-radiometer (350–2500 nm). Further, systematic non-linear mixing of snow contaminants (soil, coal, ash) in terms of size and concentration of contaminants is analysed to imitate and understand spectral response of actual field scenarios. Sensitivity of band indices along with absorption peak characteristics provide clues to discriminate the type of contaminants. SWIR region is found to be useful for discriminating size of external contaminants in snow e.g. Avalanche deposited snow from light contaminated forms. Present research provide inputs for mapping snow-mixed pixels in medium/coarse resolution remote sensing RS data (in terms of linear mixing) and suitable wavelength selections for identification and discriminating type/size of snow contaminants (in terms of non-linear mixing).