测绘档案管理现代化的若干问题分析

在测绘科技快速发展的今天,建立现代化的测绘科技档案势在必行,但是目前测绘档案管理的方法和机制相对落后于测绘科技的发展。本文分析了测绘档案管理的现状和发展方向,在此基础上,指出了测绘档案管理的主要任务,以及测绘档案管理机构转型的必要性。     

土地开发整理项日管理信息系统建设

本文首先分析了我国土地开发整理的地位和现状,回顾了“十五”期间我国在土地开发整理方面做出的巨大的成绩,展望了“十一五”期间我国在土地整理工作上的投入力度和方向。在此基础上,对我国土地整理工作所采用的技术手段进行了分析,提出了实施土地开发整理工作的信息化是解决目前存在问题的有效措施,为了保证国家每年投资数十亿资金的土地开发整理项目从审查到实施各个环节的科学性和规范性,迫切要求充分利用计算机技术、网络通信技术和3S技术等先进手段加强项目的全程管理。接着,对“国家投资土地开发整理项目管理信息系统”从功能角度进行了详细的阐述,将系统划分为若干个子系统进行开发,并对一些子系统的功能进行了阐述。最后介绍了系统的应用情况。     

Geodetic Height Determination in 2005 Qomolangma Survey

Determining the geodetic height of Mount Qomolangma was one of the very important missions in the 2005 Qomolangma height survey. There were three GPS networks in the survey: regional GPS crustal deformation network, geodetic GPS control network, and GPS measurement on the mountain summit. Data collection and processing were introduced. The final data processing strategy and reasonable geodetic height were fairly determined based on careful data analysis.     

基于ArcIMS的农业立体污染空间信息网

针对农业立体污染及时发布和数据共享的需求,运用ArcIMS建立了农业立体污染空间信息网,以达到农业立体污染防治的现代化、信息化、规范化和高效化。     

Surface Ice Flow Velocity and Tide Retrieval of the Amery Ice Shelf using Precise Point Positioning

Five days of continuous GPS observation data were collected in the frontal zone of the Amery ice shelf and subsequently post-processed using precise point position (PPP) technology based on precise orbit and clock products from the International GNSS service. The surface ice flow velocity of the observed point was derived from PPP to be 2.25 m/day toward the northeast with an azimuth of 41°. Major semi-diurnal and diurnal oceanic tide constituents could be recovered from the 5 days of PPP-derived height variations and compared well with a hydrodynamic ocean tide model. The PPP technique can replace double-difference GPS positioning in remote or hostile environments, and be used to retrieve the surface ice flow velocity without any reference station. Furthermore, the solution can be derived epoch-by-epoch with accuracy in the centimeters to decimeter range.     

An Aggregate Constraint Method for Inequality-constrained Least Squares Problems

The inequality-constrained least squares (ICLS) problem can be solved by the simplex algorithm of quadratic programming. The ICLS problem may also be reformulated as a Bayesian problem and solved by using the Bayesian principle. This paper proposes using the aggregate constraint method of non-linear programming to solve the ICLS problem by converting many inequality constraints into one equality constraint, which is a basic augmented Lagrangean algorithm for deriving the solution to equality-constrained non-linear programming problems. Since the new approach finds the active constraints, we can derive the approximate algorithm-dependent statistical properties of the solution. As a result, some conclusions about the superiority of the estimator can be approximately made. Two simulated examples are given to show how to compute the approximate statistical properties and to show that the reasonable inequality constraints can improve the results of geodetic network with an ill-conditioned normal matrix.     

A Task-Based Approach to User Interface Design for a Web-Based Hydrologic Information Systems

Hydroinformatics is a new and rapidly developing field that integrates knowledge and understanding of water resources with the latest developments in information technology to improve decision‐making in many critical applications. It encompasses methods for data capture, storage, processing, analysis and visualization, and the use of advanced modeling, simulation, optimization and knowledge‐based tools and systems infrastructure. Three types of hydrological data are most commonly used: flow rate in major rivers and streams, height of water in wells, and precipitation. To get a complete view of the state of water at a given point in space and time, one must analyze many different types of hydrological data together to derive information using an online GIS tool. To help use these disparate data sources more effectively and efficiently, we have built an online interface called the IJEDI WebCenter for Hydroinformatics using a task‐based approach. In this design, we first identify the tasks that users perform to study water‐related issues, then organize data for each task, and build task‐specific tools to present and analyze data and information. In a study involving both novices and experts in hydrology, we found that the both groups performed water‐related studies more effectively and efficiently than they would have without the WebCenter.     

机载LiDAR技术

机载LiDAR集成了GPS、IMU、激光扫描仪新一代航空遥感系统,能利用飞行获取的原始数据直接生成DEM和正射影像图,而无需任何或仅需少量的地面控制点。与传统的摄影测量技术相比,机载LiDAR可以节省大量的人力、时间和经费。在过去十年,机载LiDAR作为精确、快速的地球表面三维测量方法已得到广泛的认同,本文详细介绍了机载LiDAR的基本原理、技术结构及数据处理流程。     

我国土地资源遥感调查与监测技术体系建设构想

本文在全面分析总结我国土地资源遥感调查与监测历程的基础上,提出了我国土地资源遥感调查与监测的技术框架与体系以及主要问题和关键技术。研究结果表明我国土地资源遥感调查与监测体系建立已经极为迫切,其目标在于建立土地资源遥感调查与监测本底库和动态库,形成多系统组成的技术体系框架。