SPIE Asia-Pacific Remote Sensing最新文献_第6页

Analysis of aerosol properties derived from sun photometer and lidar over Dunhuang radiometric calibration site 敦煌辐射定标站太阳光度计和激光雷达的气溶胶特性分析

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2228016

Lin Chen, Yingying Jing, Peng Zhang, Xiuqing Hu

{"title":"Analysis of aerosol properties derived from sun photometer and lidar over Dunhuang radiometric calibration site","authors":"Lin Chen, Yingying Jing, Peng Zhang, Xiuqing Hu","doi":"10.1117/12.2228016","DOIUrl":"https://doi.org/10.1117/12.2228016","url":null,"abstract":"Duhuang site has been selected as China Radiation Calibration Site (CRCS) for Remote Sensing Satellite Sensors since 1996. With the economic development of Dunhuang city, the ambient of the radiation calibration field has changed in recent years. Taking into account the key role of aerosol in radiometric calibration, it is essential to investigate the aerosol optical properties over Dunhuang radiometric calibration site. In this paper, the CIMEL sun photometer (CE-318) and Mie-scattering Lidar are simultaneously used to measure aerosol optical properties in Dunhuang site. Data from aerosol-bands of sun photometer are used in a Langley method to determine spectral optical depths of aerosol. And Lidar is utilized to obtain information of vertical profile and integrated aerosol optical depths at different heights. The results showed that the aerosol optical depth at 500 nm wavelength during the in-situ measurement campaigns varied from 0.1 to 0.3 in Dunhuang site. And the observation results also indicated that high aerosol concentration layer mostly located at the height of about 2~4 km. These results implies that the aerosol concentration of atmosphere in Dunhuang was relatively small and suitable for in-flight calibration for remote sensing satellite sensors.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"323 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131968851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Lidar measurements of aerosol at Varanasi (25.28° N, 82.96° E), India during CAIPEEX scientific campaign 在CAIPEEX科学运动期间，印度瓦拉纳西(25.28°N, 82.96°E)气溶胶的激光雷达测量

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2223308

R. Vishnu, Y. Bhavani Kumar, Y. J. Rao, E. Samuel, P. Thara, A. Jayaraman

{"title":"Lidar measurements of aerosol at Varanasi (25.28° N, 82.96° E), India during CAIPEEX scientific campaign","authors":"R. Vishnu, Y. Bhavani Kumar, Y. J. Rao, E. Samuel, P. Thara, A. Jayaraman","doi":"10.1117/12.2223308","DOIUrl":"https://doi.org/10.1117/12.2223308","url":null,"abstract":"A compact dual polarization lidar (DPL) was designed and developed at National Atmospheric Research Laboratory (NARL) for daytime measurements of the boundary layer aerosol distribution and depolarization properties with very high vertical and temporal resolution. The lidar employs a compact flashlamp pumped Q-switched Nd:YAG laser and operates at 532 nm wavelength. The lidar system uses a stable biaxial configuration between transmitter and receiver units. The receiver utilizes a 150 mm Schmidt Cassegranin telescope for collecting laser returns from the atmosphere. The collected backscattered light is separated into co and cross-polarization signals using a polarization beam splitter cube. A set of mini-PMTs have been used for detection of light from atmosphere during daylight period. A two channel transient recorder system with built-in ADC has been employed for recording the detected light. The entire lidar system is housed in a compact cabinet which can be easily transported for field measurements. During 2014, the lidar system was installed at the Banaras Hindu University (BHU) campus, Varanasi (25.28° N, 82.96° E, 82 m AMSL) and operated for a period of three months in to support the cloud aerosol interaction and precipitation enhancement experiment (CAIPEEX) conducted by Indian Institute of tropical meteorology (IITM). During this campaign period, the lidar measurements were carried out in the vertical direction with spatial resolution of 7.5 m and time sampling of 30s. The lidar measurements revealed the occurrence of boundary layer growth during convective periods and also detected the long-range transport dust layers with significant depolarization. In the present paper, we present the lidar measurements obtained during the campaign period and discuss the observation of transport of dust layer over the experimental site with support of back trajectory analysis and satellite data. The Lidar observations were compared with the available satellite observations also presented here.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123633322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Recent changes in dust and its impact on aerosol trends over the Indo-Gangetic Plain (IGP) 印度恒河平原近期沙尘变化及其对气溶胶趋势的影响

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2223314

S. K. Pandey, H. Bakshi, V. Vinoj

{"title":"Recent changes in dust and its impact on aerosol trends over the Indo-Gangetic Plain (IGP)","authors":"S. K. Pandey, H. Bakshi, V. Vinoj","doi":"10.1117/12.2223314","DOIUrl":"https://doi.org/10.1117/12.2223314","url":null,"abstract":"A synergistic use of satellite and ground based remote sensing data has been utilized to analyze recent changes in the aerosol column loading over the Indo Gangetic Plain (IGP). Despite an overall statistically significant increase in the trend of annual mean aerosol optical depth (AOD) over the past decade, a prominent difference within seasons was observed. Summer and monsoon seasons have a slight decreasing trend, while post monsoon and winter have significant increasing trend. The optically equivalent composition inferred from ground based long term measurements of aerosol size and absorption characteristics reveals that summer and monsoon season are mostly dust dominated. Whereas, post monsoon and winter seasons are dominated by black carbon (BC) and/or other absorbing aerosols. We find that the observed decrease in AOD is associated with decrease in dust loading in the atmosphere with a large spatial extent covering the whole of North-Western part of India and IGP. Similar changes are associated with absorbing carbonaceous aerosol species during the periods showing an increasing trend. The decreasing dust loading over Indian region during summer along with increase in absorbing black carbon aerosols during the pre-monsoon and the monsoon period may have significant impact on aerosol radiative forcing and hence Indian summer monsoon rainfall.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126047803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

A ten-year global record of absorbing aerosols above clouds from OMI's near-UV observations 来自OMI近紫外线观测的10年全球吸收云层上方气溶胶的记录

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2225765

H. Jethva, Omar Torrres, C. Ahn

{"title":"A ten-year global record of absorbing aerosols above clouds from OMI's near-UV observations","authors":"H. Jethva, Omar Torrres, C. Ahn","doi":"10.1117/12.2225765","DOIUrl":"https://doi.org/10.1117/12.2225765","url":null,"abstract":"Aerosol-cloud interaction continues to be one of the leading uncertain components of climate models, primarily due to the lack of an adequate knowledge of the complex microphysical and radiative processes associated with the aerosolcloud system. The situations when aerosols and clouds are found in the same atmospheric column, for instance, when light-absorbing aerosols such as biomass burning generated carbonaceous particles or wind-blown dust overlay low-level cloud decks, are commonly found over several regional of the world. Contrary to the cloud-free scenario over dark surface, for which aerosols are known to produce a net cooling effect (negative radiative forcing) on climate, the overlapping situation of absorbing aerosols over cloud can potentially exert a significant level of atmospheric absorption and produces a positive radiative forcing at top-of-atmosphere. The magnitude of direct radiative effects of aerosols above cloud depends directly on the aerosol loading, microphysical-optical properties of the aerosol layer and the underlying cloud deck, and geometric cloud fraction. We help in addressing this problem by introducing a novel product of optical depth of absorbing aerosols above clouds retrieved from near-UV observations made by the Ozone Monitoring Instrument (OMI) on board NASA’s Aura platform. The presence of absorbing aerosols above cloud reduces the upwelling radiation reflected by cloud and produces a strong ‘color ratio’ effect in the near-UV region, which can be unambiguously detected in the OMI measurements. Physically based on this effect, the OMACA algorithm retrieves the optical depths of aerosols and clouds simultaneously under a prescribed state of atmosphere. The algorithm architecture and results from a ten-year global record including global climatology of frequency of occurrence and above-cloud aerosol optical depth, and a discussion on related future field campaigns are presented.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126962038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Dust storm events over Delhi: verification of dust AOD forecasts with satellite and surface observations 德里沙尘暴事件:用卫星和地面观测验证沙尘AOD预报

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2223706

Aditi Singh, G. Iyengar, J. George

{"title":"Dust storm events over Delhi: verification of dust AOD forecasts with satellite and surface observations","authors":"Aditi Singh, G. Iyengar, J. George","doi":"10.1117/12.2223706","DOIUrl":"https://doi.org/10.1117/12.2223706","url":null,"abstract":"Thar desert located in northwest part of India is considered as one of the major dust source. Dust storms originate in Thar desert during pre-monsoon season, affects large part of Indo-Gangetic plains. High dust loading causes the deterioration of the ambient air quality and degradation in visibility. Present study focuses on the identification of dust events and verification of the forecast of dust events over Delhi and western part of IG Plains, during the pre-monsoon season of 2015. Three dust events have been identified over Delhi during the study period. For all the selected days, Terra-MODIS AOD at 550 nm are found close to 1.0, while AURA-OMI AI shows high values. Dust AOD forecasts from NCMRWF Unified Model (NCUM) for the three selected dust events are verified against satellite (MODIS) and ground based observations (AERONET). Comparison of observed AODs at 550 nm from MODIS with NCUM predicted AODs reveals that NCUM is able to predict the spatial and temporal distribution of dust AOD, in these cases. Good correlation (~0.67) is obtained between the NCUM predicted dust AODs and location specific observations available from AERONET. Model under-predicted the AODs as compared to the AERONET observations. This may be mainly because the model account for only dust and no anthropogenic activities are considered. The results of the present study emphasize the requirement of more realistic representation of local dust emission in the model both of natural and anthropogenic origin, to improve the forecast of dust from NCUM during the dust events.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"303 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116585009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

High-sensitivity remote detection of atmospheric pollutants and greenhouse gases at low ppm levels using near-infrared tunable diode lasers 使用近红外可调谐二极管激光器对低ppm水平的大气污染物和温室气体进行高灵敏度远程检测

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2222785

A. Roy, A. Upadhyay, A. Chakraborty

{"title":"High-sensitivity remote detection of atmospheric pollutants and greenhouse gases at low ppm levels using near-infrared tunable diode lasers","authors":"A. Roy, A. Upadhyay, A. Chakraborty","doi":"10.1117/12.2222785","DOIUrl":"https://doi.org/10.1117/12.2222785","url":null,"abstract":"The concentration of atmospheric pollutants and greenhouse gases needs to be precisely monitored for sustainable industrial development and to predict the climate shifts caused by global warming. Such measurements are made on a continuous basis in ecologically sensitive and urban areas in the advanced countries. Tunable diode laser spectroscopy (TDLS) is the most versatile non-destructive technology currently available for remote measurements of multiple gases with very high selectivity (low cross-sensitivity), very high sensitivity (on the order of ppm and ppb) and under hazardous conditions. We demonstrate absolute measurements of acetylene, methane and carbon dioxide using a fielddeployable fully automated TDLS system that uses calibration-free 2f wavelength modulation spectroscopy (2f WMS) techniques with sensitivities of low ppm levels. A 40 mW, 1531.52 nm distributed feedback (DFB) diode laser, a 10 mW, 1650 nm DFB laser and a 1 mW, 2004 nm vertical cavity surface emitting laser (VCSEL) are used in the experiments to probe the P9 transition of acetylene, R4 transition of methane and R16 transition of carbon dioxide respectively. Data acquisition and on-board analysis comprises a Raspberry Pi-based embedded system that is controllable over a wireless connection. Gas concentration and pressure are simultaneously extracted by fitting the experimental signals to 2f WMS signals simulated using spectroscopic parameters obtained from the HITRAN database. The lowest detected concentration is 11 ppm for acetylene, 275 ppm for methane and 285 ppm for carbon dioxide using a 28 cm long single-pass gas cell.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132053344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Measurement of formaldehyde total content in troposphere using DOAS technique: improvements in version 1.3a of IAP retrieval algorithm 使用DOAS技术测量对流层甲醛总含量:对IAP检索算法1.3a版的改进

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2229231

O. Postylyakov, A. Borovski

{"title":"Measurement of formaldehyde total content in troposphere using DOAS technique: improvements in version 1.3a of IAP retrieval algorithm","authors":"O. Postylyakov, A. Borovski","doi":"10.1117/12.2229231","DOIUrl":"https://doi.org/10.1117/12.2229231","url":null,"abstract":"Formaldehyde (HCHO) is a significant constituent of the atmospheric chemistry involved in a lot of chemical reactions. It is directly emitted by anthropogenic and biogenic sources and, more significantly, by production during oxidation of methane and other VOCs. So HCHO is used as an indicator of local pollution by VOCs. HCHO has a sufficiently large absorption cross-section in the UV spectral region to be detected by the technique of the differential optical absorption spectroscopy (DOAS). We present here new version 1.3a of the algorithm for retrieval of the HCHO total content in the troposphere from DOAS observations of the scattered solar radiation developed in A.M. Obukhov Institute of Atmospheric Physics (IAP). The new version has reduced retrieval error but negligible bias with respect to the previous versions. DOAS measurements of scattered solar radiation are performed at Zvenigorod Scientific Station (ZSS, 55°41'49''N, 36°46'29''E) located in 38 km west from Moscow Ring Road by a MAX-DOAS instrument since 2008. We provide preliminary results of the HCHO total content measurements in the troposphere observed in 2010-2012 obtained by the revised retrieval algorithm.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132266553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

A novel atmospheric Temperature Sounding Unit: system design and performance analyses 一种新型大气温度测深装置:系统设计与性能分析

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2228155

P. Chakraborty, Priyanka Gupta, D. B. Dave, N. Desai, T. Misra

{"title":"A novel atmospheric Temperature Sounding Unit: system design and performance analyses","authors":"P. Chakraborty, Priyanka Gupta, D. B. Dave, N. Desai, T. Misra","doi":"10.1117/12.2228155","DOIUrl":"https://doi.org/10.1117/12.2228155","url":null,"abstract":"This paper reports the development of a millimeter-wave space-borne atmospheric Temperature Sounding Unit (TSU) in Indian Space Research Organization (ISRO). This is ISRO’s first leap towards millimeter-wave technology. The sensor has several new accomplishments to its credit which include among others, the philosophy of sounding channel selection, the new assortment of temperature sounding channels, simultaneous observation of both polarizations of all channels, compact dual-band scanning Gregorian reflector antenna, indigenously developed black-body target for in-orbit calibration, in-house developed millimeter-wave RF front-end and pre-detection automatic gain control method. The prime feature of this instrument is its unique set of channels which can profile the earth’s atmosphere from surface to 40 km altitude with vertical resolution ranging from less than a km near surface to ±2.5 km at 30km altitude. The channels are predominantly off-resonant frequencies in the 50―60 GHz O2 absorption spectrum which offer near-uniform attenuation and hence more channel-bandwidth and better temperature sensitivity and yet have adequate overlap of their weighting functions to achieve the desired vertical resolution. These channels are different and have fewer bands from what has been flown in all earlier sounding missions worldwide e.g. AMSU-A, SSMIS, ATMS etc. The TSU radiometer has been characterized thoroughly using ingenious methods such as low-power active RF energizing along with frequency sweep. This is a compact, low-mass, low-power instrument and has been configured for the ISRO mini-satellite (IMS-2) bus. The flight model with improved hardware performance is being built and a suitable opportunity of flying it is being explored.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127365627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of multi-satellite rainfall products over India during monsoon 季风期间印度多卫星降雨产品的评估

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2223311

A. Mitra, S. Prakash, D. S. Pai, A. K. Srivastava

{"title":"Evaluation of multi-satellite rainfall products over India during monsoon","authors":"A. Mitra, S. Prakash, D. S. Pai, A. K. Srivastava","doi":"10.1117/12.2223311","DOIUrl":"https://doi.org/10.1117/12.2223311","url":null,"abstract":"Simulation and prediction of Indian monsoon rainfall at scales from days-to-season is a challenging task for numerical modelling community worldwide. Gridded estimates of daily rainfall data are required for both land and oceanic regions for model validation, process studies and in turn for model development. Due to recent developments in satellite meteorology, it has become possible to produce realistic near real-time gridded rainfall datasets at operational basis by combining satellite estimates with rain gauge values and other available in-situ observations. Microwave and space based radar based estimates of rainfall has revolutionised the preparation of rainfall datasets especially for tropics. However, a variety of multi-satellite products are available over Indian monsoon region from a variety of sources. Popular products like TRMM TMPA3B42 (RT and V7), GsMaP, CPC/RFE, GPCP and GPM are available to end users in various space/time scales for applications and model validation. In this study, we show the representation and skill of monsoon rainfall from a variety of multi-satellite products over the Indian region. The bias and skill of multi-satellite rainfall are evaluated against gauge based observations. It was found that the TRMM based TMPA was one of the best dataset for Indian monsoon region. Attempt is made to compare the latest GPM based data with other products. The GPM based rainfall product is seen to be superior compared to TRMM.","PeriodicalId":165733,"journal":{"name":"SPIE Asia-Pacific Remote Sensing","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121605239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A simple method for the detection of PM2.5 air pollutions using MODIS data 利用MODIS数据检测PM2.5空气污染的简单方法

SPIE Asia-Pacific Remote Sensing Pub Date : 2016-05-05 DOI: 10.1117/12.2223947

Y. Kato

引用次数: 1