A miniature robotic plane meteorological sounding system

This article presents a miniature robotic plane meteorological sounding system (RPMSS), which consists of three major subsystems: a miniature robotic plane, an air-borne meteorological sounding and flight control system, and a ground-based system. Take-off and landing of the miniature aircraft are guided by radio control, and the flight of the robotic plane along a pre-designed trajectory is automatically piloted by an onboard navigation system. The observed meteorological data as well as all flight information are sent back in real time to the ground, then displayed and recorded by the ground-based computer. The ground-based subsystem can also transmit instructions to the air-borne control subsystem. Good system performance has been demonstrated by more than 300 hours of flight for atmospheric sounding.     

The Heat Airspace Cloud Map in Terminal Airspace of Airports Based on Air Passenger Flow and a Case Study in Beijing International Airport

The calculation of air passenger flow density and the recognition of heat airspace in terminal areas of large hub airports is a new challenging research in the intelligent era, that is, using big data can automatically generate air passenger flow and basic rules. Aimed for the air passenger flow density in airport and its relationship between occupation and airspace, based on the establishment of the Beijing International Airport 1 h flight, which consists of basic parameters-latitude, longitude and height, additional parameters-dogleg and speed of trajectories, time parameters, a spatio-temporal data set by clustering trajectories and calculation of aircraft trajectories points was made up. Then, heat cloud map of flight trajectories under 4D conditions was generated. Cell was used to identify the basic parameters and time parameter of heat airspace; grid graphs of flight trajectories were used to identify additional parameters and explain the influence on heat airspace; probability fitting graphs were used to verify the accuracy of 4D results. The conclusion is as follows: there are two areas of Beijing International Airport, which have the high density and at two different heights there also exist hot peaks; flight trajectories and speed of trajectories also affect the heat airspace. The variation of heat airspace caused by different flight occupancy time in 4D recognition was revealed. The method realized the 4D heat cloud map of flight trajectories, which is better for detailed and accurate information construction, expression of spatial changes, and more the parameters of density and visualization of temporal and spatial range, which can assist the automatic dynamic airspace sectorization and decision making on airspace allocation, and also have a definite reference meaning in alleviating the contradiction between the current air traffic demand and limited airspace.     

斜孔长螺旋钻进技术的试验研究

重点阐述了作者在分析、研究试验成果资料基础上得出的有关斜孔长螺旋钻进功率消耗、规程参数、孔弯规律及相应技术措施的初步结论。     

Spatial Disparities in the Expansion of the Chinese Ethnoburb of Los Angeles

Suburban Chinatowns are intriguing subjects for study and comparison. These ethnic suburbs, or ethnoburbs, have emerged to coexist or compete with the older downtown Chinatowns traditionally found in American central cities. Their growth since the 1960s challenges many traditional assumptions regarding the spatial and cultural assimilation of immigrants in U.S. society, namely that ethnicity would decline with the geographic and socioeconomic mobility of immigrants from the inner city into the suburbs. We examined recent growth trends in the Chinese ethnoburb of the San Gabriel Valley region of Greater Los Angeles, through analysis and mapping of U.S. Census data, and discovered ethnic persistence rather than spatial and cultural assimilation. We also discovered the ethnoburb is differentiated between a lower-class core and two middle-to-upper class fringe districts. Though there is some linguistic assimilation on the northwest fringe, the majority of the ethnoburban population continues to speak Chinese. Linguistic isolation is not a barrier to achieving a higher socioeconomic class position in the Chinese ethnoburb of Los Angeles. An earlier version of this paper was presented at the American Sociological Association Annual Meeting, San Francisco, California, August 2004.     

地形影响的飞机颠簸及其数值仿真实验

首先利用中尺度数值模式ARPS模拟气流过山生成飞行数值仿真所需要的风场，然后利用飞机载荷因数变量方程进行飞机飞行的数值仿真试验。研究结果表明，气流过山产生的山脉重力波由于风切变临界层破碎，一方面能在对流层产生较强的湍流引起晴空飞机颠簸，另一方面也能在山脉背风面产生强烈下坡风，背风转子环流及低空湍流，影响飞机的起飞和着陆。揭示了飞机在过山脉地形背风面所产生的大气湍流中飞行时引起飞机颠簸的物理机制，有助于增强飞机颠簸的预测能力和飞行气象保障能力。     

一种新的航空伽马能谱测量数据改正方法

在地形起伏较大的山区进行航空伽马能谱测量时,使用传统的方法做高度改正,往往造成不小的误差,为此笔者提出一种飞行高度与地形的同步改正的方法.该方法快捷简便,简单易行,较好地解决了上述难题.     

高空飞行器被动段运行轨迹精确预测方法研究

高空飞行器被动段运动学状态方程是典型的非线性常微分方程,难以给出其解析解。为了精确预测飞行器被动段运行轨迹,目前常用的解决方法是给出其数值解。在建立飞行器运动学状态方程基础上,提出采用四阶龙格库塔法求解这一常微分方程组,给出了初值的选取方法。采用仿真试验对提出方法的可行性和有效性进行了验证,结论表明:龙格库塔法可以有效计算出飞行器运动学状态方程数值解,能够高精度地预测出飞行器的运行轨迹。     

论江西气象培训体系改革与建设

从省级气象培训中心改革与建设,以及市、县气象局学习点和局校合作等方面,对江西气象培训体系改革与建设进行了论述,认为省级气象培训中心应以远程教育培训为主,开展全员基础业务和新技术、新知识的培训;市、县气象局是远程教育培训的学习点。要按照“创新教育培训内容、改进教育培训方式、整合教育培训资源、优化教育培训队伍、提高教育培训质量”的要求,建设有气象特色的人才培养体系,满足气象事业发展对各类人才的需求。     

影响飞行的两次强沙尘暴天气分析

根据天气特点、热力作用,雷达回波、地形等方面对乌海机场2005年5月26日、2006年7月24日发生的两次强沙尘暴天气进行分析,分析结果表明,造成这两次沙尘暴的天气形势均为西北气流型,由于上游沙漠地带地表温度高,低层热动力辐合抬升,导致下地表出现上升运动,造成沙尘暴天气。     

Real time wave forecasting using neural networks

Forecasting of ocean wave heights, with warning time of a few hours or days, is necessary in planning many operation-related activities in the ocean. Such information is currently derived by numerically solving the differential equation representing wave energy balance. The solution procedure involved is extremely complex and calls for very large amounts of meteorological and oceanographic data. This paper presents a complementary and simple method to make a point forecast of waves in real time sense based on the current observation of waves at a site. It incorporates the technique of neural networks. The network involved is first trained by different algorithms and then used to forecast waves with lead times varying from 3 to 24 h. The results of different training algorithms are compared with each other. The neural output is further compared with the statistical AR models.