微波遥感大气特性及天气变化

本文介绍了用5mm(52.9GHz,54.SGHz),1.35cm(22.235GHz)和8mm(35.3GHz)微波辐射计遥感大气特性和天气变化。评价全天候(不包括雨)遥感大气温度、压力层结、大气水汽含量及云中液态水量的能力及微波遥感监测天气变化的能力。文中还建立了遥感大气特性的方法,用研制的微波辐射计系列在野外观测实验中,证实晴天及阴天遥感大气温度、湿度、压力层结及云中液态水量的可行性。在监测天气变化中,分析了微波遥感气团变化、云雨过程、大气扰动等内容,它可供临近预报及人工降水中使用。     

光学遥感大气气溶胶和水汽的研究

本文用研制的辐射计(0.5—1.06微米七个波段),在北京地区进行了一年的观测,从中分析了大气气溶胶的特性、气溶胶粒子浓度和谱分布的变化规律及其和气象条件的关系。根据遥感大气水汽含量,和探空资料进行比较,取得了一致的结果。文中还讨论了气溶胶和水汽对大气光学厚度的影响以及在水汽吸收带中,大气光学厚度和大气水汽含量的关系。     

大气痕量气体NO_2的研究

为了测量大气中NO_2的含量,我们研制了自动太阳光谱光度仪。在地面遥感测量太阳直射光谱的4470—4490波段,从辐射传输方程及极大相似法,导出了大气中NO_2的含量。而大气中NO_2的浓度,在北京郊区测量了数月。本文对测量结果进行了讨论。     

微波遥感大气层结的原理和实验

为了微波遥感大气温度、湿度、压力层结和云雨要素,用5毫米-3厘米微波辐射计接收大气微波噪音。用5毫米波段遥感10公里以下大气温度、压力层结,与无线电探空仪探测结果进行了比较,在5公里以下,温度偏差为2-3K,气压偏差<2毫巴.用1.35厘米波段遥感大气湿度层结和水汽总含量,与探空资料比较,水汽总含量偏差为3％。并用5毫米(54.4千兆)和1.35厘米波段联合观测进行了大气温度和湿度的遥感实验。最后,对用8毫米和3厘米波段对云雨大气遥感进行了讨论.     

微波遥感土壤湿度的研究

本文研究了湿润土壤的微波辐射特性及微波遥感土壤湿度的方法。首先用终端短路线法测量土壤介电常数和湿度的关系;介电常数的实部和虚部都是随着土壤湿度增加而加大的。用研制的微波辐射率仪测量土壤微波辐射率和湿度的关系。土壤微波辐射率随着湿度加大而降低的。土壤湿度不同引起显著的亮度温度变化。本文还研究了在土壤中微波的衰竭厚度以及土壤中湿度分布对辐射率的影响;土壤表面粗糙度对于辐射率的作用。从原理分析和实验结果表明,微波辐射计是遥感土壤湿度的良好工具,3.2cm波段较8.5mm波段测土壤湿度优越,它不但灵敏度高、穿透深度较深而且受表面粗糙度的影响亦小。     

STUDY OF MICROWAVE REMOTE SENSING OF THE SOIL MOISTURE

This article includes a study of the microwave emissivity characteristics of moist soil and the method of microwave remote sensing of the soil moisture. The relation between soil dielectric constant and moisture was measured with terminal short circuit line method. The microwave emissivity of soil decreases with the increase of humidity because the real andimage parts of dielectric constant increases with the humidity. The relation between soil microwave emissivity and humidity is measured with the microwave emissivity meter made by us. Considerable change of brightness temperature is caused by different soil humidity. This article also presents the exhausted depth and the influence of humidity distribution on emissivity, the effection of soil surface roughness on emissivity. The theoretical analysis and experiment results have shown that microwave radiometer is a helpful instrument in the remote sensing of soil moisture. 3.2 cm waveband, with higher sensibility, deeper penetrate depth and less effect o     

STUDY ON ATMOSPHERIC TRACE GAS NO_2

The content of NO_2 in the atmosphere is one of the important factors for atmospheric environmental appreciation. An automatic solar spectrophotometer (ASS) system has been developed in order to observe the content of NO_2 in the atmosphere. The column content of atmospheric NO_2 has been obtained by use of radiative transfer equation and maximum resembled method, through the ground-based observation of direct solar radiative spectrum of 4470—4490. Some months' observations of NO_2 have been made in the suburbs of Beijing. The results have been discussed here.     

EXPERIMENTAL STUDY ON REMOTE SENSING OF ATMOSPHERIC SOUNDING BY MEANS OF MULTIFREQUENCY MICROWAVE RADIOMETERS

In this paper, the principle and method of microwave remote sensing atmospheric sounding are described. In order to carry out the experimental study, the 4 channels in 5mm—1.35 cm band microwave radiometers have been constructed. The field experiment in September-October 1981 was carried out. In this paper, the results obtained by different inversion methods are compared with each other. The experimental result shows that it will be satisfactory, if the temperature profile and inversion of lower atmosphere are derived from remote sensing of 2 channels (frequencies: 52.8 Gc and 54.4. Gc) in 5 mm band. The atmospheric humidity can be obtained from the remote sensing of 1.35 cm band. While the change of air mass exists, signal reveals itself significantly in the atmospheric microwave radiation. The variations of atmospheric temperature and humidity have been analysed and compared with those obtained from radiosonde.     

STUDY ON OPTICAL REMOTE SENSING ATMOSPHERIC AEROSOL AND WATER VAPOUR CONTENT

With the multichannel radiometer of visible and infrared band, ground-based observationsof the intensity of solar spectrum and the atmospheric optical thickness have been made andthe method of remote sensing atmospheric aerosol and water vapour content have been studied.With the radiometer(seven channels of 0.5--1.06μ), observations have been made for morethan one year in Beijing. The atmospheric water vapour content obtained from remote sensingis in accord with that from radiosonde data. In this paper, the characteristics of atmosphericaerosol and total water vapour content are discussed, and the influences of aerosol and thewater vapour on the atmospheric optical thickness and the relationship between them in thewater absorption region are also treated with.     

多频段微波遥感大气层结的实验研究

本文概述了微波遥感大气温度、湿度层结的原理和反演方法.为了进行实验,研制和改善了5mm—1.35cm波段中4个频段的微波辐射计.本文讨论了1981年9—10月,多频段微波遥感大气层结的实验结果,并用不同的反演方法进行了比较.实验结果表明,用5mm波段 52.8Gc和 54.4 Ge两频段遥感大气温度层结,反映低空大气温度和低空逆温性能良好.用1.35cm波段可遥感大气湿度状况.当气团变化时,在微波遥感信息中有所反映,并和无线电探空仪测量结果是一致的。