大气遥感探测概貌

当前,大气遥感技术主要从三方面发展,微波遥感、光学遥感以及声学遥感。其中微波遥感兴起得最早,紧接着红外技术的发展,激光的发现又开辟了光学遥感。声学遥感是六十年代末、七十年代初才崛起,目前,它的发展还不如上述二种遥感技术那末广泛。 起初,遥感技术都在地面上使用,到了六十年代,气象卫星的出现,又开辟了一个新的领域——空间遥感技术。这样从遥感技术的使用场地可划分为空间遥感和地面遥感。 大气遥感探测理论的任务就是将一种波(电磁波或声波)在大气传播过程中的种种变化与气象要素建     

地基大气遥感探测技术简介

随着科学技术的新进展,气象事业近20年来有了飞速的发展,数值预报、计算机通信及数字数据处理、图形工作站等新技术推动了气象工作向自动化、智能化方向发展,较好地解决了数据传输、加工、存储及输出的问题,但是目前我国大气探测装备仍较落后,这表现在时空分辨率低,自动化程度低,数据质量差,这种状态急需改变。现在已有一些成熟的遥测和遥感技术用于大气探测,如自动气象站、气象卫星和天气雷达,本文着重就气象基本参数如温、湿和风等的地基大气遥感探测计划作一简要的介绍。1 为何要发展地基大气遥感探测1.1遥感的优越性目前我国业务上使用的常规高空探测方法延用几十年了,它自身存在着明显的不足。表现在:     

激光探测大气扩散参数

利用红宝石激光雷达,在烟粒形状任意(或晶轴取向任意)和烟粒成分和谱分布稳定,以及一次散射和独立散射条件下,探测了烟羽相对浓度的垂直剖面分布,从而获得不同天气条件下离烟源下风向一定距离范围内大气扩散参数σ_y和σ_z。     

气象观测的新阶段—大气遥感探测

近年来,在气象业务和研究领域里,一系列新型的探测大气的技术系统正陆续出现,例如微波气象雷达,激光雷达、声雷达、以及气象卫星和微波、红外、可见光辐射等等,这类探测技术统称为大气遥感探测。它已经为我们提供了一系列丰富多采的大气图     

低层垂直大气廓线遥感探测技术进展

不同探测方式的遥感设备针对各类目标物的探测能力有较大区别,靠单一设备难以承担综合信息的获取,较好的设计是通过多种设备协调探测,信息互补,综合分析,融合处理,最终得到可有效用于业务的完整信息。从当前气象预报业务发展的实际情况看,对于数百千米以上尺度天气系统的中短期预报,数值模式预报结果基本上已超越了预报员的能力,预报员虽还能做些订正改进,但多数情况下也只能仅此而已。     

大气探测

大气探测Ｃ波段测风雷达天线挡住球影时的捕捉目标方法Ｃ波段测风雷达观测探空气球时，初始阶段要由机内光学引导系统引导雷达实现自动跟踪。在某些天气条件下，光学跟踪器～雷达天线～探测气球三者往往成一直线，即雷达抛物面天线遮挡住球影，致使无法引导。我们在实践中...     

大气探测

大气探测地面最高温度表示值偏低原因天气晴朗时，常出现地面最高温度表读数低于地面温度表１４ｈ读数。众所周知，地面最高温度表每日２０ｈ观测后要做示度调整。由于每日都要拿动，致使其接触的土壤比地面温度表疏松。疏松的土壤空气相对增多，热容量增大，导热率减小，...     

大气探测

大气探测太阳辐射日最大值挑取之我见按照《气象辐射观测方法》８．１．５的规定，因仪器故障或其它原因，使记录仪打印（显示）的直接辐射日最大值有误时，应从各定时打印（显示）的瞬时值中挑选最大者。该处理规定没有考虑浑浊度观测时记录器打印（显示）的直接辐射值。...     

大气探测

大气探测虹吸雨量计自记迹线缺测处理之我见虹吸雨量计自记迹线缺测是台站经常遇到的问题。《规范》规定,若缺测时间内的累计量无法从自记纸上直接计算出来时,可用定时观测的降水量与两定时之间正常自记迹线的累计量计算得出的累计量代替,即缺测时间内的累计量＝定时观...     

大气探测

大气探测南阳市降水污染特点不管是从理论上还是从对早期荒僻地区雪样测量结果都表明,在天然条件下,大气中的ＣＯ２溶于纯净雨水中,降水的ｐＨ值在５．６５左右。于是,降水ｐＨ值是否小于５．６已成为是否为酸雨的标准。通过对南阳市观测站１９９５～１９９７年酸雨资...     

由太阳近红外直接辐射强度遥测大气水汽总含量

用一台单色计在地面测量太阳0.873微米和0.942微米辐射强度比值。该比值可以有效地消除气溶胶和雷利散射,仅剩下水汽吸收效应,从而能够较好地确定大气垂直路径和斜程路径的水汽总含量。本文还详细讨论了获得校正曲线的方法。     

两波段微波辐射计遥感云天大气的可降水和液态水

本文在薄大气近似下计算了1.35cm和8.5mm波段上云天大气辐射传输,建立了微波辐射亮度温度与云中液态水含量、大气衰减与水汽总量的经验关系,讨论了由两波段的辐射测量遥感云天条件下的水汽总量和云中含水量的方法,并进行了实验验证.在我们的实验条件下,微波遥感的云天水汽总量与探空值的相对偏差约为10%.     

Remote sensing of rainfall parameters by laser scintillation correlation method — Numerical simulation of the retrieving

This paper is a continuation of an earlier paper. In this paper, we investigate the stability and the representativeness of the rainfall rate h determined by the B2*-h relationship in the scintillation method of remote sensing of rain parameters, develop an adequate scheme for retrieving rainfall rate and raindrop size distribution (DSD), and finally characterize the technique by numerical simulations. The results show that the B2*-h relationship is quite stable for all the raindrop size distributions used in present simulations; the measured rainfall rate is not severely affected by the distribution of the path-weighting function of B2*. The retrieving of DSDs is successful even if the observation errors are assumed in simulations. The rainfall rates derived from the ratrieving of DSD is more accurate than those determined by B2*-h relationship. This method is superior in heavier rains.     

Remote sensing of rainfall parameters by laser scintillation correlation method-complete equation and numerical simulation

Remote sensing of rainfall parameters by using laser scintillation effect, originally proposed by Wang et al. is a unique approach for getting rainfall rate and raindrop size distribution with excellent temporal and spatial representativeness. In this paper, we review Wang's work, point out the weakness of their basic equations, then establish a complete remote sensing equation in which the observable quantity, the scintillation of light intensity is used. The relationships between the rainfall parameters and the spatial-temporal correlation function of light scintilla tion are systematically discussed. Numerical investigations show that this equation gives at least four different ways to obtain the rainfall rate, and the kernel functions for raindrop size distribution are of excellent resolution. At last, the retrieval scheme of the drop size distribution is discussed.     

On lidar application for remote sensing of the atmosphere

This paper introduces some advanced subjects on lidar remote sensing of the atmosphere, emphasizing recent studies and developments in lidar application for measuring ozone, cloud, aerosol, atmospheric temperature, moisture, pressure and wind.     

Remote sensing of cloud liquid water

Summary A method is presented to infer cloud liquid water path (LWP in kg/m²) over the ocean from passive microwave measurements of SSM/I. The algorithm to retrieve LWP is based on simulated satellite observations. They are calculated with a radiative transfer model applied to about 3000 radiosonde ascents over the Atlantic Ocean. Since radiosonde observations do not contain direct information about cloud water and ice, these parameters are parameterized based on relative humidity and temperature using modified adiabatic liquid water density profiles. A multiple linear regression is applied to the simulated radiances and the calculated LWP to derive the algorithm. The retrieval accuracy based on the regression analysis including instrumental noise is 0.03 kg/m². Validation of the LWP-algorithm was pursued through a comparison with measurements of a ground-based 33 GHzmicrowave radiometer on board of R.V. Poseidon during the International Cirrus Experiment 1989 at the North Sea (ICE'89). The LWP values agree within the range of uncertainty caused by the different sampling characteristics of the observing systems. The retrieval accuracy for clear-sky cases determined using colocated METEOSAT data over the North Sea is 0.037 kg/m² and confirms the accuracy estimated from regression analysis for the low liquid water cases.The algorithm was used to derive maps of monthly mean LWP over the Atlantic Ocean. As an example the Octobers of the 5 years 1987–1991 were selected to demonstrate the interannual variability of LWP. The results were compared with the cloud water content produced by the climate model ECHAM-T2 from the Max-Planck-Institut Hamburg.Observations during ICE'89 were used to check the accuracy of the applied radiative transfer model. Brightness temperatures were calculated from radiosonde ascents launched during the overpass of DMSP-F8 in cloud-free situations. The channel-dependent differences range from about –2 to 3 K.The possibility to identify different cloud types using microwave and infrared observations was examined. The main conclusion is that simultaneous microwave and infrared measurements enable the separation of dense cirrus and cirrus with underlying water clouds. A classification of clouds with respect to their top heights and LWP was carried out using a combination of SSM/I derived LWP and simultaneously recorded Meteosat IR-data during ICE'89.With 11 Figures     

大气遥感研究的进展

大气遥感是六十年代全面兴起的新型大气探测方法。它的发展将为掌握大气运动和变化规律提供更丰富、更深刻的观测资料,是推动近代大气科学研究进步的重要工具。早在六十年代中期,如何把空间、激光、红外和微波等近代技术迅速应用到我国大气科学研究,建立新的大气探测系统,适应气象为我国国防与国民经济现代化建设服务的实际需要,促进我国大气科学赶超世界先进水平的问题,就引起了我国著名地球物理学家赵九章和气象学家顾震潮的密切注意,并且着手组织力量,制定发展大气遥感的研究规划。从1965年到现在,在党的领导下,我们努力排除并克服了各种干扰和困难,全面开展了激     

Remote sensing of temperature profiles in the boundary layer

The technique using a ground-based infrared broad-band scanning radiometer to measure temperature pro-files in the boundary layer is suggested. The methods for retrieving and reducing its errors are discussed, and that of correction to water vapour absorption is also given.     

地球大气红外间接遥测的最佳测值条件分析

利用估计空间三类不同性质又相互联系的特征态,对红外大气间接遥测的最佳探测条件作了数值试验,结果表明:对同样的热探测问题,使用不同性质的特征态作判据,可以得到相当不同的一组独立通道数.