航空遥感在海域动态监视监测工作中的应用

本文立足于烟台市海域使用动态监视监测实际情况,通过分析航空遥感在海域动态监管工作中的优缺点,将航空遥感技术应用于海域使用动态监测中。监测结果表明:航空遥感可以实现海域空间资源监测、区域建设用海规划监测和重点项目监测等海域使用动态监测,可以满足海域动态监管的各类型监视监测工作要求。     

Sea Surface Determination Using Long-Range Kinematic GPS Positioning and Laser Airborne Depth Sounder Techniques

Precise long-range kinematic GPS positioning requires the use of carrier phase measurements, the data processing of which suffers from the technical challenges of ambiguity resolution and cycle slip repair. In this paper, the combination of an ambiguity recovery technique and a linear bias correction method has been used to overcome such problems. An experiment was conducted to test the utility of this technique to determine aircraft height to high accuracy, over very long baselines (of the order of one thousand kilometres), in support of the Laser Airborne Depth Sounder (LADS). From a comparison of four independently derived trajectories, this airborne GPS kinematic positioning experiment has confirmed that the sea surface can be determined to centimetre accuracy. The sea surface profiles thus obtained can be used to correct the errors introduced by long period ocean swells.     

机载激光扫描测高数据滤波

机载激光扫描测高数据的滤波和分类是获取高精度数字高程模型的关键,也是国际上目前研究的重点和难点之一。本文详细研究了机载激光扫描测高数据滤波的方法,对现有各种滤波算法进行了综合评价,指出了现有方法的不足,在此基础上首次将"移动曲面拟合预测"滤波算法用于机载激光扫描测高数据滤波处理。试验结果表明该算法自适应性强,计算速度快,滤波效果好。通过对不同测区的数据进行实验,给出了滤波前后的对比结果。     

高精度航空重力测量系统分项指标设计分析

为研制高精度航空重力仪,开展了高精度航空重力仪分项指标设计与分析,为高精度航空重力测量系统设计提供依据。笔者基于航空重力测量的数学模型,归纳出影响航空重力测量的主要因素;结合航空重力测量的相关理论公式,使用理论模型,推导出各影响因素的误差模型;开展了各项误差的分析研究,并通过设定合理的分项指标精度来有效地控制分项误差,确保航空重力测量精度优于0.6×10-5m/s2。     

Sub-Cm Subsidence Measurements With The Wide-Angle Airborne Laser Ranging System

The Wide-Angle Airborne Laser Ranging System (WA-ALRS) is aninstrument developed at IGN with the aim of measuring landsubsidence with sub-cm accuracy. The instrument provides rangemeasurements that are used to estimate the co-ordinates of aground-based network of cube-corner retroreflectors (CCRs).Millimeter accuracy on relative radial co-ordinates has beendemonstrated in a ground-based experiment and centimeter accuracyhas been obtained in a recent airborne experiment. The mainlimitation in the latter experiment came from the low link budgetat longer distances. In this paper we analyze the performanceexpected with two different detector modules (avalanchephotodiodes with amplifiers). Laboratory measurements are used tocharacterize detector parameters and estimate ranging accuracy.Numerical simulations predict a 2–3 mm accuracy in the verticalco-ordinate with these detectors combined to a 2-km aircraftaltitude, a 20 laser beam divergence, a 250-m CCR separation and 10³ measurements per CCR.     

机载PMS粒子测量系统实时处理显示技术系统的研制

机载粒子测量系统（PMS）的云降水观测数据只能实时监视并存入磁带，不能在飞机上实时处理显示，用于指挥人工增雨作业。该文介绍了疳原有的数据据磁带记录改为由机载身长机记录并实时处理显示的硬件结构及其工作原理，以及研制的系统及其软件功能。     

航空重力测量的滤波处理及最佳波长分辨率的探讨

根据航空重力测量的数据性质，对其滤波处理中最佳滤长分辨率的确定，提出了一种采用静态飞行数据进行检测的方法－即利用静态飞行数据处理后的重力异常误差平方和最小的原则。并对其在航空重力测量中的必要性做了检验和说明。     

An assessment of inversion methods for AEM data applied to environmental studies

Airborne electromagnetic (AEM) surveys are currently being flown over populated areas and applied to detailed problems using high flight line densities. Interpretation information is supplied through a model of the subsurface resistivity distribution. Theoretical and survey data are used here to study the character and reliability of such models. Although the survey data were obtained using a fixed-wing system, the corresponding associations with helicopter, towed-bird systems are discussed. Both Fraser half-space and 1D inversion techniques are considered in relation to their ability to distinguish geological, cultural and environmental influences on the survey data. Fraser half-space modelling provides the dual interpretation parameters of apparent resistivity and apparent depth at each operational frequency. The apparent resistivity was found to be a remarkably stable parameter and appears robust to the presence of a variety of at-surface cultural features. Such features provide both incorrect altitude data and multidimensional influences. Their influences are observed most strongly in the joint estimate of apparent depth and this accounts for the stability of the apparent resistivity. Positive apparent depths, in the example data, result from underestimated altitude measurements. It is demonstrated that increasingly negative apparent depths are associated with increasing misfits between a 1D model and the data. Centroid depth calculations, which are a transform of the Fraser half-space parameters, provide an example of the detection of non-1D influences on data obtained above a populated area. 1D inversion of both theoretical and survey data is examined. The simplest use of the 1D inversion method is in providing an estimate of a half-space resistivity. This can be undertaken prior to multilayer inversion as an initial assessment. Underestimated altitude measurements also enter the problem and, in keeping with the Fraser pseudo-layer concept, an at-surface highly resistive layer of variable thickness can be usefully introduced as a constrained parameter. It is clearly difficult to ascribe levels of significance to a ‘measure’ of misfit contained in a negative apparent depth with the dimensions of metres. The reliability of 1D models is better assessed using a formal misfit parameter. With the misfit parameter in place, the example data suggest that the 1D inversion methods provide reliable apparent resistivity values with a higher resolution than the equivalent information from the Fraser half-space estimates.     

浅谈华北地台北界中段划分问题

作者在研究华北地台航磁资料推断解释的过程中,综合对比各种资料,发现该地台北界中段(即东经112°—117°之间)应沿北纬42°35′—40′通过。这就扩大了该地台北缘范围,也对扩大地台北缘找矿远景有重要意义。     

机载微波辐射计测云中液态含水量

文中介绍了 2 0 0 1～ 2 0 0 2年 4～ 7月吉林省人工增雨期间 ,在中国首次进行的机载对空微波辐射计外场飞行观测试验。观测结果表明 ,仪器可以灵敏地探测出层状云中垂直路径积分云液态水和过冷水含量及其变化 ,揭示了在层状云中嵌入的对流区中有丰富的垂直积分过冷水含量 ,量级可达 10 3 g/m2 。与地面雷达PPI回波强度呈正相关。本文还根据飞机上升 (或下降 )过程的探测数据 ,给出了水平均匀的层状云液态含水量的垂直廓线的实例 ,并进一步讨论了这种方法的应用前景。