气象导航设备——卫星云图接收系统海上试验及结果评定方法

在介绍了接收气象卫星云图的意义，全球大气监测网、卫星云图接收规定及对舰载卫星云图接收系统的要求之后，立足靶场现有条件，运用“黑箱理论”，分析并提出了气象卫星云图接收系统海上试验和结果评定方法。该方法已用于某舰用某型气象卫星云图接收系统海上鉴定试验。     

FY-3A气象卫星HRPT/MPT接收系统研究与应用

FY-3A气象卫星是我国第二代极轨气象卫星,具备高性能的综合探测能力,能够提供多种图像和定量产品,可广泛应用于天气预报、环境监测和专业气象服务等各个方面。概要介绍了FY-3A气象卫星的特点和作用,卫星接收地面站的链路设计以及地面站HRPT/MPT接收系统作用、组成、功能和技术特点,并在此基础之上展望了未来地面接收系统的发展方向。     

新一代地球观测系统介绍及地面接收设备方案设想

本文介绍了地球观测系统(简称EOS)、卫星的参数及其下行链路。并应用我厂多年研制气象卫星接收设备的经验，简单介绍EOS卫星地面接收设备的设计方案，供感兴趣的工程技术人员参考。     

“风云二号”08星通过出厂评审 发射在即

正据www.sitp.ac.cn网站报道,近日,"风云二号"08星通过出厂评审。经审定,"风云二号"08星技术性能优良、质量受控且具备出厂条件,将于年底执行发射任务。"风云二号"08星是我国地球同步静止轨道气象卫星,是"风云二号"03批静止气象卫星工程的第二颗业务应用卫星。该卫星采用自旋稳定姿态。作为我国第一代静止轨道气象卫星,"风云二号"卫星的云图等气象资料已为我国数千个气象观测台站应用,并被周边国家与地区所接收。2012年,由上海技物所承研的"风云二号"F星扫描辐射计显著减少了可见杂光的影响,精细控制了各波段响应光谱、提高了定量化水平,增强了扫描机构的可靠性、实现了区域机动观     

风云三号气象卫得及广州地面数据接收处理系统

历经8年研制的风云三号极轨气象卫星A星,已于2008年5月27日上午11时02分在我国太原卫星发射中心。用长征四号丙运载火箭发射成功。风云三号极轨气象卫星A星是目前为止,装载探测仪器最多、技术水平最高、技术难度最大的民用卫星。它具有获取全球、全天候、多谱段、三维、定量探测地表、海洋及空间环境参数的能力,与美国的新一代气象与环境监测卫星NPOESS、欧洲的新一代极轨气象卫星METOP相当。世界气象组织已将FY一3卫星纳入新一代世界极轨气象卫星网。广州地面数据接收处理系统是风云三号极轨气象卫星地面应用系统的一个重要组成部分,是为风云三号卫星而建设的全新的气象卫星业务子系统。该系统建设规模大,技术先进及复杂,由相关单位研制。在安装、调试及试运行的过程中,广州站根据自身的经验及需求对该系统进行了一些改进和完善。该系统已验收并投入业务运行。     

风云四号接收天线新技术的研究及应用

风云四号气象卫星是采用三轴稳定的大型遥感平台、装载多台观测仪器的第二代静止气象卫星,其地面接收天线主要任务就是要保证准确捕获卫星,高可靠、高精度地跟踪卫星,为系统上下行信道提供高品质的射频通道。风云四号B星在风云四号A星的基础上增加Ka频段数传。风云四号15米Ka/X/S频段天线是其地面应用系统获取工程数据和测控系统的重要组成部分,用于风云四号B星的Ka频段信号的接收、X频段信号的发射和接收、S频段信号的发射和接收。Ka频段的频率高、波长短、波束窄的特点对地面接收天线带来了更高的要求,为此,文章主要分析研究风云四号地面接收天线新技术及应用。     

FY-2气象卫星信号的开发利用

详细介绍了基于风云二号静止气象卫星信号实现电离层闪烁监测、云图接收、太空环境参数接收的设备设计、构成。该设备主要用于实时监测分析风云二号卫星信号因电离层变化而造成的幅度闪烁和相位闪烁。由于静止卫星不存在运动所附带的变化,利用其稳定的L波段遥测信号来监测电离层闪烁,优越性显著。风云卫星展宽云图接收设备目前已遍布全国,该设备在其跟踪遥测及云图接收的基础上进行开发,易于组网监测。电离层闪烁监测的结果,将对空间的探测和通讯技术的发展具有重大的意义。     

卫星数据的实时接收与存储

介绍了卫星数据通信中数据的实时接收与存储系统的实现方法。它分为硬件和软件两部分:硬件部分讨论了计算机数据摄入原理和数据摄入卡的设计原理;软件部分给出了数据存储的实现方法,并给出了接收程序流程图。最后,给出了依次原理设计的气象卫星图像接收系统的使用情况。     

利用矩阵实现气象卫星信号的可靠接收

矩阵是一种可一进多出的电器设备,能实现信号的选择和扩展。在风云三号系列气象卫星地面数据接收系统链路中使用了射频矩阵、中频矩阵、数据矩阵后,使得原两套相互独立的数据接收链路在射频、中频、基带3个频点上有了纽带、联系和交换,从而在射频、中频、基带3个节点上实现灵活切换、灵活组配,大大提高了设备利用率,确保卫星信号不因链路中某台设备故障而中断,使卫星信号的接收、传输更加可靠。     

利用电磁环境自动测试系统对卫星地球站进行监测研究

1接到对卫星地球站监测任务2007年10月中旬,黑龙江省气象局请求黑龙江省无线电监测站对佳木斯四丰山卫星地球站进行电磁环境测试。该站是接收我国风云-3号极轨气象卫星的地球站,也是我国风云-3号应用系统一期建设工程中三     

一种静止气象卫星云图动画的质量评估算法

静止气象卫星云图在天气预报和公众服务等领域发挥着非常重要的作用。气象卫星 处理系统是一个非常复杂的系统。卫星及地面系统的软硬件问题经常会使得分发云图的质量难以得到保证。 利用基于图像的欧氏距离算法提出了一种可对实时生产的静止卫星云图进行质量评估的方法,并且对其业务 可行性进行了讨论。通过与历史数据进行比对,该方法可以判识90 %以上的错误云图。     

基于卫星资料的我国沙尘天气监测方法

根据沙尘粒子的辐射传输特性和空间分布特征,利用气象卫星资料能够有效监测沙尘天气发生的时间、范围和强度等,并可计算出相关的定量信息。监测方法一般包括基于卫星波段特征的监测方法和基于卫星云图目视解译的监测方法。利用卫星监测分析与遥感应用系统(Satellite Monitoring Analysis Remote-sensing Toolkit, SMART)的沙尘监测模块可以对沙尘监测结果进行年度统计。统计数据显示,沙尘天气高发区域有三个,即新疆地区,内蒙古西部、河西走廊地区,以及内蒙古中东部、东北、华北地区;2007年、2010年、2012年和2015年的卫星监测沙尘累计覆盖面积较大,达到500万平方公里以上。新一代静止气象卫星——FY-4A卫星在沙尘监测方面突显出了巨大潜力,这将有利于沙尘天气的云图目视解译。     

基于气象卫星数据的我国沿海悬空波导反演方法初步研究

悬空波导的测量方法有直接测量和间接测量两种.传统的直接测量手段只能得到单点的波导信息.间接测量也存在一定的局限性,不能获取高时空分辨率的波导多维空间信息.而静止气象卫星由于其高时空分辨率观测的特点,能对我国沿海海域大气环境进行时空四维监测.文中借鉴国外一种基于气象卫星数据反演悬空波导的方法,利用我国静止气象卫星FY-2G的云分类和云顶温度数据、地面观测数据及探空数据,分析该方法中各影响因素的敏感性,初步检验了该方法在我国沿海的适用性.提出建立本地海域悬空波导反演方法的几个关键问题：①选用高精度云顶温度反演数据;②选择合适规定层（850hPa或700hPa）;③根据本地数据得到一些参量的经验值;④建立本地参数化方案.下一步将寻找更多我国不同沿海海域的事例进行验证,该方法有希望运用到我国沿海大气波导监测中,为我国沿海大气波导监测和反演提供一种新方法新技术.     

Query-by-shape in meteorological image archives using the pointdiffusion technique

The authors work on meteorological satellite image archives and provide a novel and useful query-by-shape tool. To this aim, they first present the point diffusion technique (PDT), a fast and efficient method for shape similarity evaluation. Thanks to its very structure, this approach is suitable to handle objects whose shape is not well defined and can be represented by a set of sparse points. PDT is thus suitable for application to similarity-based retrieval from remotely sensed image archives, where shapes are hardly defined but are still among the major features of interest. Moreover, they prove here that PDT is almost as effective as more standard procedures for shape-based database queries, although significantly faster. In other words, it manages to combine retrieval speed and precision, the features of greatest importance for a first remote sensing data prescreening in many applications. Archives of meteorological satellite images are typical examples of very large-sized, remote sensing-based databases with a special attention for shape features. Each meteorological satellite produces terabytes of data every day, a large part of which is not immediately analyzed and ends being stored in archives. The application of PDT to such a database is presented and discussed, and a comparison with a standard method developed for meteorological shape analysis is provided     

Proposed novel technique for the measurement of antenna gain in satellite earth-stations

In the design of communication satellite systems, knowledge of earth-station receive antenna gain and gain stability is essential. Gain measurement relies on the establishment of a constant receive signal flux. This paper attempts to show how a standard gain horn and a reference source can be used together with a closed-loop satellite ALC circuit to provide a stable, known received flux at the input of the earth-station antenna with unknown gain. Theoretical limitations of the technique are discussed as a forerunner to future practical measurements. Elements of the reference receive chain are transportable and can therefore be used to cross-calibrate antennas, even in the case of receive-only terminals.     

Evaluating evapotranspiration at local and regional scales

Combining remotely sensed data with ground-based meteorological data allows the evaluation of evapotranspiration (the evaporation of water from soil and plant surfaces) at local and regional scales. Remote sensors can provide information on reflected solar radiation and surface temperatures. The remaining variables in the energy balance equations must be measured at ground level, estimated, modeled, or ignored. It is how these variables are evaluated that distinguish the several approaches to estimating evapotranspiration. In general, regional scale methods would apply to part or all of a satellite image, and use meteorological data from local weather stations. Local scale techniques would rely largely on airborne remote sensors and on-site measurements of the pertinent meteorological factors at the time of remote-data collection. In this paper, methods for estimating evapotranspiration on both local and regional scales are reviewed, and some factors that complicate its measurement are discussed.     

Low Computational Complexity in Low-Cost GNSS Receivers

One of the key issues in low-cost GNSS receivers is the computational complexity. One of the computational components of the GNSS receivers is the satellite positioning calculations. The main focus of this paper is to reduce the computational burden of this stage of processing. In this paper, four different models to fit the GPS and GLONASS satellites orbit are investigated. These models are compared with each other in terms of their computational load and accuracy, and the models have good accuracy and less computational load are selected. Among these four methods, the Hermite model and the Chebyshev model are superior to other methods for determining orbits of GPS and GLONASS satellites, respectively. In order to evaluate the performance of these models, two different data including ground stations data and measured data by GNSS receivers are used. The results show that these two models can improve the computational burden by about 90% compared to conventional methods like the Runge–Kutta and the Keplerian parameters that used in GNSS receivers.

     

利用南海水面开展我国静止气象卫星红外通道在轨辐射定标

中国遥感卫星辐射校正场以青海湖水面作为遥感卫星红外探测通道外场辐射定标的场地.我国静止气象卫星风云二号(FY-2)系列是自旋稳定卫星,其红外通道无法进行在轨时的星上绝对定标,而青海湖对于位于东经105°赤道上空的FY-2卫星来说,卫星天顶角有36°,超过了外场辐射校正测量规范要求.本文介绍了利用我国南海海面水体辐射,进行与静止气象卫星的同步测量试验,开展卫星红外通道在轨外场辐射定标处理的可行性研究.在分别对FY-2B与FY-2C的测量数据处理后,初步确定我国南海海面可以作为我国静止气象卫星在轨辐射定标的场地.     

Interference between satellite systems in non-geostationary orbits

Satellites are considered in arbitrary orbits, and interference between them and other satellites or earth-stations is calculated. The composite interference from a complete system is found by summing over the set of visible satellites. One starts with the Keplerian orbital parameters and assumed antenna patterns and transmitter characteristics. Using classical orbital mechanics and a series of co-ordinate transformations, one determines the location of any satellite in the frame of reference of any other satellite or earth-station. Conventional interference methods are then used to find the result.