具有运动补偿高精度海洋气象多参数模拟仪的研制

针对船舶气象仪的综合检查过程中检测周期长、人工排查效率低以及传统的自动气象站传感器信号模拟器的模拟精度低,没有相关运动补偿算法导致此类系统不适应海洋船舶应用环境的问题,对气象要素传感器的高精度信号采样电路、信号输出、软件滤波和运动补偿等方面进行了研究。通过分析传感器和船舶气象仪的原理,设计了各个气象参数的采样电路、信号模拟电路、触摸屏、GPS和电子罗盘采样与模拟电路,并在近海测试过程中进行了运动补偿模型测试,并基于STM32微控制器进行了该仪器的系统检测实验。研究测试结果表明：该系统具有低功耗、高可靠性、高精度的特点,能应用于海上环境,同时具有对船舶实时定位、气象要素实时模拟和采集、运动补偿多项功能。并且本系统精度在运动补偿后,系统测量方差为0.019 3 m/s,精度提高至接近真实值,均符合《海洋调查规范第3部分：海洋气象观测》的标准。     

一部研究区域历史地理的力作——评蓝勇主编《长江三峡历史地理》

在举世瞩目的三峡水库蓄水工程开始前夕,西南师范大学蓝勇教授主编的《长江三峡历史地理》由四川人民出版社出版,可以说是从学人角度为这项伟大的世纪工程献上了一份特殊的厚礼。《长江三峡历史地理》系国家社会科学“九五”规划项目,也是我国第一部系统研究三峡地区历史地理的大部头学术著作。通读《长江三峡历史地理》,明显地感到该书体现了以下几个特色:一、浓重的现实关怀和服务意识历史学早有经世致用的传统,历史地理学更是与社会现实、国计民生关系密切。可以说关注现实是区域历史地理学的一个重要理念和功能。当三峡蓄水高度达到175米时,不难想象千年三峡历史风貌势必大有改变,并不可避免地带来许多自然与现     

锚泊式浮标中的GPS测量值

锚泊式浮标中的ＧＰＳ测量值（德国，德国ＦＡＦ默尼黑大学，天文物理测地学研究所（ＩＡＰＧ），ＧｎｔｅｒＷ·Ｈｅｉｎ，ＨｅｌｍｕｔＢｌｏｍｅｎｈｏｆｅｒ，ＨｅｒｂｅｒｔＬａｎｄａｕ，ＥｄｕａｒｄａＴａｖｅｉｒａ）１引言１９８９年初期，ＩＡＰＧ建议ＥＳＡ／...     

基于CR1000 的海洋剖面测量平台双重数据系统设计

为新型海洋剖面测量平台设计了一种基于CR1000数据采集仪的数据存储安全和数据读取方便的双重数据系统.第一重数据,分散存储于自容式传感器,传感器的上位机软件通过CR1000来读取;第二重数据,集中存储在CR1000的数据扩展模块中,通过海洋剖面测量平台的上位机软件直接读取.实验结果表明,该存储方案可有效地实现采样数据的存储和读取,从而最大限度地保证了新型海洋剖面测量平台的数据安全.     

Estimation of hydraulic conductivity in an alluvial system using temperatures

Well water temperatures are often collected simultaneously with water levels; however, temperature data are generally considered only as a water quality parameter and are not utilized as an environmental tracer. In this paper, water levels and seasonal temperatures are used to estimate hydraulic conductivities in a stream-aquifer system. To demonstrate this method, temperatures and water levels are analyzed from six observation wells along an example study site, the Russian River in Sonoma County, California. The range in seasonal ground water temperatures in these wells varied from <0.2 degrees C in two wells to approximately 8 degrees C in the other four wells from June to October 2000. The temperature probes in the six wells are located at depths between 3.5 and 7.1 m relative to the river channel. Hydraulic conductivities are estimated by matching simulated ground water temperatures to the observed ground water temperatures. An anisotropy of 5 (horizontal to vertical hydraulic conductivity) generally gives the best fit to the observed temperatures. Estimated conductivities vary over an order of magnitude in the six locations analyzed. In some locations, a change in the observed temperature profile occurred during the study, most likely due to deposition of fine-grained sediment and organic matter plugging the streambed. A reasonable fit to this change in the temperature profile is obtained by decreasing the hydraulic conductivity in the simulations. This study demonstrates that seasonal ground water temperatures monitored in observation wells provide an effective means of estimating hydraulic conductivities in alluvial aquifers.     

Search for Transits of a Short-Period, Sub-Saturn Extrasolar Planet Orbiting HD 46375

Precise brightness measurements of HD 46375 have been acquired with an automatic telescope to search for transits of its short-period, sub-Saturn extrasolar planet. Transits of the companion do not occur, indicating that the inclination of the orbit i is less than 83 degrees and sini is less than 0.992. This upper limit on sini still preserves the possibility that the mass of the planet is less than Saturn's. Analysis of the photometry for HD 46375 reveals no photometric variability larger than 0.0001+/-0.0002 mag at the orbital period of the planet. This effectively eliminates starspots and stellar pulsations as the cause of the radial velocity variations used to infer the planet's existence.     

基于最小二乘法与RBF神经网络的溶解氧检测系统设计

为克服温度对溶解氧传感器的影响,对极谱型溶解氧检测系统的溶解氧电极激励源、高精度信号采样、软件标定和温度补偿等方面进行研究。通过对极谱型溶解氧传感器工作原理进行分析,设计了极谱型溶解氧传感器检测电路;根据溶解氧电极的温度特性,设计了基于NTC(负温度系数)热敏电阻的硬件温度补偿电路,并利用最小二乘法及RBF神经网络构建了软件温度补偿模型。利用饱和蒸馏水进行温度补偿实验,结果表明:经温度补偿后,该溶解氧检测系统的相对误差及采样波动均在1%以内,大大减小了传感器的非线性误差,测量精度和稳定性均可满足应用要求。     

适用于专用微波遥感成像仪的新的地球物理算法

一、引言自发射第一颗"专用的微波遥感成像仪"(SSM/I)以来,三年的时间已经过去了.真正经过检验并正式发表的、估算全球范围内海洋上空大气参数的方法仍少得惊人.因为我们的兴趣在于用SSM/I的数据对海洋上空的天气系统做个例研究,所以我们要组合成一套统一的计算方法,使我们能够从原始的SSM/I图象提取出最多的有用的环境信息,同时又照顾到遥感器的分辨率和交叉参数的污染.虽然这一目标只部分得以实现,