高分五号发射成功并进入工作模式

正2018年5月9日02时28分,我国在太原卫星发射中心用长征四号丙运载火箭成功发射高分五号卫星。5月13日12时52分,中国遥感卫星地面站密云站已成功地跟踪并接收到高分五号卫星的首轨下行数据,意味着高分5号已进入工作模式。高分五号卫星是高分专项的重要组成部分,是我国实现     

地理信息产品(成果)质量检验的现状与发展趋势

回顾了模拟测绘和数字化测绘时期地理信息产品质量检验的流程、内容、手段、标准,论述了信息化测绘及信息化测绘时期质量检验的特点,并对三个时期的地理信息产品质量检验作了对比。     

Oil well produced water discharges to the North Sea. Part II: comparison of deployed mussels (Mytilus edulis) and the DREAM model to predict ecological risk

Large volumes of water often are produced with oil and gas from offshore platforms. The produced water is separated from the oil and gas and either reinjected into a deep formation or discharged to the ocean. The Norwegian oil and gas industry advocates ecological risk assessment as the basis for managing produced water discharges to the North Sea. In this paper, we compare estimates of ecological risks to water-column communities based on data on hydrocarbon residues in soft tissues of blue mussels deployed for a month near offshore platforms and based on predictions of the Dose related Risk and Effect Assessment Model (DREAM). The study was performed near produced water discharges to the Tampen and Ekofisk Regions of the Norwegian Sector of the North Sea. Because polycyclic aromatic hydrocarbons (PAH) are considered the most important contributors to the ecological hazard posed by produced water discharges, comparisons made here focus on this group of compounds. The mussel approach is based on predicted environmental concentrations (PECs) of individual PAH, estimated from PAH residues in mussels following deployment for a month near several produced water discharges, and predicted no effects concentrations (PNECs) based on a K(ow) regression model. In the DREAM method, PECs for three PAH fractions are estimated in the three-dimensional area around produced water discharge with the DREAM model. PNECs for each fraction are based on the chronic toxicity of a representative PAH from each fraction divided by an assessment factor to account for uncertainty in the chronic value. The mussel method gives much lower estimates of ecological risk than the DREAM method. The differences are caused by the much lower PNECs used in DREAM than derived from the regression model, and by the lower concentrations of aqueous PAH predicted by DREAM than estimated from PAH residues in mussel tissues. However, the two methods rank stations at different distances from produced water discharges in the same order and both identify 2- and 3-ring PAHs as the main contributors to the ecological risk of produced water discharges. Neither method identifies a significant ecological risk of PAH in the upper water column of the oil fields. The DREAM model may produce an overly conservative estimate of ecological risk of produced water discharges to the North Sea.     

GIS中位置信息的通用数据质量模型及其质量控制

在地理信息系统的数据原子中加入了数据质量量测指标。提出了地理数据在地理信息系统各阶段的数据质量模型,归纳了影响地理信息系统数据质量的因素和３种质量控制方法。     

论地理数据定义不确定性和量测不确定性的二象性

在将ＧＩＳ数据不确定性分类为定义不确定性和量测不确定性的基础上,采用辩证法和认识论的观点讨论了二者之间的关系和适用范围。定义不确定性是指客观实体特征向地理信息系统空间目标转化过程中引起的不稳定性;量测不确定性是指对空间目标赋值的不确定性。最后给出了地理数据总体不确定性的度量模型。     

一种道路定线曲线元素的通用算法

在现有道路定线曲线元素计算方法的基础上，分析各种情况下曲线元素的计算方法，给出曲线元素的通用算法，最后给出运算实例。     

改进的时空数据基态修正方法

分析已有基于基态修正模型的5种数据存储方式,在此基础上提出多基态多级差文件修正方法、多基态单级差文件修正方法.与已有方法相比,提出的两种方法具有节省存储空间,历史数据恢复快而且不受历史久远影响的特点.多基态多级差文件修正方法与多基态单级差文件修正方法相比没有增加存储空间,但提高了数据恢复速度.讨论基态距阈值的确定方法,认为基态距阈值与时空数据库每次更新的目标数相关,更新目标数大时基态距阈值较小,目标数小时基态距阈值相对较大.     

33项测绘地理信息国家标准即将实施

正2017年12月29日,国家质检总局和国家标准委发布公告(2017年第32号),宣布33项测绘地理信息国家标准在2018年7月1日开始实施。这33项标准是:卫星导航定位基准站网服务规范:GB/T35769-2017、卫星导航定位基准站网服务管理系统规范:GB/T35768-2017、卫星导航定位基准站网基本产品规范:GB/T35767-2017、地图导航定位产品通用规     

空间数据现势度的概念

在回顾空间数据时间维不确定区间的基础上 ,分析了量测空间数据现势性的不足之处 ,提出了空间数据现势度的概念 ,研究了现势度的四个性质及现势度和生命区间的影响因素。实例演示了现势度的使用方法。