Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472392
J. Bobak, C. Ruf
An algorithm is discussed which can significantly lower the rms errors in integrated cloud liquid water and water vapor retrieval from radiometric brightness temperature. This algorithm makes use of the effective radiating temperature of the atmosphere which is estimated from surface temperature, cloud base temperature, and cloud base height. The surface temperature is easily measured, while the cloud base temperature and the cloud base height may be measured by use of a pyrometer and a ceilometer, respectively. The effective radiating temperature T/sub eff/ is estimated at two separate frequencies corresponding to the two frequencies used to measure radiometric brightness temperature, and these estimates are then used to modify the brightness temperatures. For a data base compiled at University Park, Pennsylvania, the estimates of effective radiating temperature reduced the rms error in retrieving cloud liquid water content from 37 to 21 /spl mu/m, and reduced the rms error in retrieving water vapor under cloudy conditions from 0.20 to 0.11 cm. The reduction in the uncertainty in retrieved liquid water content was consistent with that achieved by Han and Thomson (1) for tropical conditions. Han and Thomson used measurements of cloud base height and cloud base temperature, along with a climatological mean effective radiating temperature to improve their retrievals.<>
{"title":"An algorithm for improving the retrieval of cloud liquid water and water vapor using effective radiating temperature of clouds","authors":"J. Bobak, C. Ruf","doi":"10.1109/COMEAS.1995.472392","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472392","url":null,"abstract":"An algorithm is discussed which can significantly lower the rms errors in integrated cloud liquid water and water vapor retrieval from radiometric brightness temperature. This algorithm makes use of the effective radiating temperature of the atmosphere which is estimated from surface temperature, cloud base temperature, and cloud base height. The surface temperature is easily measured, while the cloud base temperature and the cloud base height may be measured by use of a pyrometer and a ceilometer, respectively. The effective radiating temperature T/sub eff/ is estimated at two separate frequencies corresponding to the two frequencies used to measure radiometric brightness temperature, and these estimates are then used to modify the brightness temperatures. For a data base compiled at University Park, Pennsylvania, the estimates of effective radiating temperature reduced the rms error in retrieving cloud liquid water content from 37 to 21 /spl mu/m, and reduced the rms error in retrieving water vapor under cloudy conditions from 0.20 to 0.11 cm. The reduction in the uncertainty in retrieved liquid water content was consistent with that achieved by Han and Thomson (1) for tropical conditions. Han and Thomson used measurements of cloud base height and cloud base temperature, along with a climatological mean effective radiating temperature to improve their retrievals.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133401370","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472358
David H. Staeh, J. Kerekes, I. Physicaiissues
Remote sensing of atmospheric parameters with space-based passive microwave and optical sensors matured from research experiments in the 1960s and 1970s to operational systems in the 1970s and 1980s. Atmospheric temperature and humidity profiles can be retrieved using the infrared carbon dioxide resonances, the microwave oxygen resonances, and the water vapor resonances in both spectral bands. Superior retrievals can be obtained by combining these sensors, taking advantage of the superior ability of microwaves to penetrate many cloud types and to respond better to low temperatures and negative lapse rates, while simultaneously taking advantage of the high spatial resolution, channel count, and sensitivity of modern infrared sensors, together with their reduced sensitivity to surface effects. Microwave and infrared soundings from satellites have been combined since their operational introduction in the 1970s, and progress continues to be made. These evolving techniques are reviewed.<>
{"title":"Combined microwave and optical atmospheric remote sensing techniques: a review","authors":"David H. Staeh, J. Kerekes, I. Physicaiissues","doi":"10.1109/COMEAS.1995.472358","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472358","url":null,"abstract":"Remote sensing of atmospheric parameters with space-based passive microwave and optical sensors matured from research experiments in the 1960s and 1970s to operational systems in the 1970s and 1980s. Atmospheric temperature and humidity profiles can be retrieved using the infrared carbon dioxide resonances, the microwave oxygen resonances, and the water vapor resonances in both spectral bands. Superior retrievals can be obtained by combining these sensors, taking advantage of the superior ability of microwaves to penetrate many cloud types and to respond better to low temperatures and negative lapse rates, while simultaneously taking advantage of the high spatial resolution, channel count, and sensitivity of modern infrared sensors, together with their reduced sensitivity to surface effects. Microwave and infrared soundings from satellites have been combined since their operational introduction in the 1970s, and progress continues to be made. These evolving techniques are reviewed.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133225133","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472399
A. England, J. Galantowicz
Soil-Vegetation-Atmosphere Transfer (SVAT) schemes are used to estimate land-atmosphere moisture, energy, and momentum fluxes and provide boundary forcing to atmospheric models (AMs). Model studies of continental climate have shown that predictions of AMs are highly dependent upon soil moisture and latent energy flux between the land and the atmosphere. There are several popular SVAT schemes. Among these are the Biosphere-Atmosphere Transfer Scheme (BATS) and the Simple Biosphere model (SiB). These models have been validated to some extent through field experiments, but the validations have not extended over many terrains or through several seasons. The Michigan Cold Region Radiobrightness (MCRR) model is a first generation SVAT model that links land-atmosphere hydrologic processes in northern prairie grasses to satellite radiobrightness for the purposes of validation and correction of the SVAT state. The model has two modules, a thermal module that tracks isotherms in the soil as forced by the energy balance at the land-atmosphere interface, and a radiobrightness module that employs a halfspace soil model to predict radiobrightness at the SSM/I frequencies of 19.35, 37.0, and 85.5 GHz. The MCRR model was tested with data from our first Radiobrightness Energy Balance Experiment, REBEX-l near Sioux Falls, South Dakota, during October, 1992, through April, 1993. One cause for the poor performance of the radiobrightness module was moisture and temperature dependent absorption, emission, and scattering within the grass canopy. A refractive model for grass is to make predictions. It is then compared to REBEX-1 data for a 21 day, snow-free period in October, 1992.<>
{"title":"Moisture in a grass canopy from SSM/I radiobrightness","authors":"A. England, J. Galantowicz","doi":"10.1109/COMEAS.1995.472399","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472399","url":null,"abstract":"Soil-Vegetation-Atmosphere Transfer (SVAT) schemes are used to estimate land-atmosphere moisture, energy, and momentum fluxes and provide boundary forcing to atmospheric models (AMs). Model studies of continental climate have shown that predictions of AMs are highly dependent upon soil moisture and latent energy flux between the land and the atmosphere. There are several popular SVAT schemes. Among these are the Biosphere-Atmosphere Transfer Scheme (BATS) and the Simple Biosphere model (SiB). These models have been validated to some extent through field experiments, but the validations have not extended over many terrains or through several seasons. The Michigan Cold Region Radiobrightness (MCRR) model is a first generation SVAT model that links land-atmosphere hydrologic processes in northern prairie grasses to satellite radiobrightness for the purposes of validation and correction of the SVAT state. The model has two modules, a thermal module that tracks isotherms in the soil as forced by the energy balance at the land-atmosphere interface, and a radiobrightness module that employs a halfspace soil model to predict radiobrightness at the SSM/I frequencies of 19.35, 37.0, and 85.5 GHz. The MCRR model was tested with data from our first Radiobrightness Energy Balance Experiment, REBEX-l near Sioux Falls, South Dakota, during October, 1992, through April, 1993. One cause for the poor performance of the radiobrightness module was moisture and temperature dependent absorption, emission, and scattering within the grass canopy. A refractive model for grass is to make predictions. It is then compared to REBEX-1 data for a 21 day, snow-free period in October, 1992.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"46 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113958069","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472315
D. Klugmann, R. Judaschke
Describes a millimetre radar system for the measurement of clouds. The 94 GHz cloud profiler is a bistatic system with an average transmitted power of 1.6 W and it is built up using only semiconductor devices. Due to the modular design power upgrade is possible. It's size without antenna is approx. 65cm/spl times/42cm/spl times/22cm. The weight of the system is about 25 kg. The initial signal is generated by a voltage controlled CW Gunn oscillator. This signal synchronizes a 500 mW IMPATT oscillator by injection locking. The heart of the system is a power combiner consisting of four 500 mW IMPATT oscillators. A fraction ofthe transmitted signal is used as a local oscillator of the mixer which converts the received signal to IF-level. The mixer used for deriving the IF signal from transmitted and received signals has a noise temperature of T=625K at a operation temperature of 300K. The diameter of the antenna used for the first tests is 157 mm.<>
{"title":"A 94 GHz solid state FM-CW-Doppler radar profiler","authors":"D. Klugmann, R. Judaschke","doi":"10.1109/COMEAS.1995.472315","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472315","url":null,"abstract":"Describes a millimetre radar system for the measurement of clouds. The 94 GHz cloud profiler is a bistatic system with an average transmitted power of 1.6 W and it is built up using only semiconductor devices. Due to the modular design power upgrade is possible. It's size without antenna is approx. 65cm/spl times/42cm/spl times/22cm. The weight of the system is about 25 kg. The initial signal is generated by a voltage controlled CW Gunn oscillator. This signal synchronizes a 500 mW IMPATT oscillator by injection locking. The heart of the system is a power combiner consisting of four 500 mW IMPATT oscillators. A fraction ofthe transmitted signal is used as a local oscillator of the mixer which converts the received signal to IF-level. The mixer used for deriving the IF signal from transmitted and received signals has a noise temperature of T=625K at a operation temperature of 300K. The diameter of the antenna used for the first tests is 157 mm.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123153724","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472360
R. Harrington, B. Grady, C. Hearn
A 4.3 GHz microwave radiometer has been developed for the NASA Langley radiometer technology laboratory. Measurements of avalanche noise diode stabilities, low noise amplifiers noise and gain stabilities, and passive microwave component stabilities such as PIN diode switches, circulator switches, RF filters, etc. are planned in the near future. The goals of this development to achieve accuracies of 0.1 K and radiometric sensitivities of 10 /spl mu/K should be achieved in the near future. Technology transfer of microwave radiometer stability data to enhance the use of both real and synthetic aperture radiometers for passive microwave remote sensing is planned through the use of memorandum of agreements (MOAs) between NASA-Langley and private industry. Discussions are underway with several companies interested in data from this laboratory.<>
{"title":"Design and development of a microwave radiometer technology laboratory","authors":"R. Harrington, B. Grady, C. Hearn","doi":"10.1109/COMEAS.1995.472360","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472360","url":null,"abstract":"A 4.3 GHz microwave radiometer has been developed for the NASA Langley radiometer technology laboratory. Measurements of avalanche noise diode stabilities, low noise amplifiers noise and gain stabilities, and passive microwave component stabilities such as PIN diode switches, circulator switches, RF filters, etc. are planned in the near future. The goals of this development to achieve accuracies of 0.1 K and radiometric sensitivities of 10 /spl mu/K should be achieved in the near future. Technology transfer of microwave radiometer stability data to enhance the use of both real and synthetic aperture radiometers for passive microwave remote sensing is planned through the use of memorandum of agreements (MOAs) between NASA-Langley and private industry. Discussions are underway with several companies interested in data from this laboratory.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125913201","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472336
K. Tomiyasu, P. Dorian, P. Eitner
The remote measurement of geosurface radiances using microwave and thermal infrared radiometers from satellite platforms has been an attractive and challenging goal. A significant impediment is data corruption by the intervening atmosphere. Attempts to correct for the atmosphere apparently have not been reported at microwave frequencies, but have been addressed at thermal infrared wavelengths. For thermal infrared, papers have been written reporting on multi-spectral and multi-angle measurements to infer the absolute value of geosurface temperature. A dual-angle radiometric technique to measure sea-surface temperature from an aircraft has been reported by Saunders. His technique made measurements at zenith angles near 0/spl deg/ and 60/spl deg/, and the reported absolute accuracies are 0.2 degree C. Since the path length was short with small path loss and insignificant path radiance, two unknowns are involved and measurements at two angles were sufficient for solution. As the platform altitude is increased, the number of significant factors increases, such as upwelling radiance from a lossy atmosphere and downwelling radiance scattered from the surface. With an increase in the number of significant factors, the number of independent measurements must also increase for solution. In this paper, an attempt is made to examine the utility of a triple-angle measurement method on the same area or pixel to extend the earlier dual-angle measurement technique. It is assumed that the next significant factor for some examples maybe the radiance from the intervening path. The purposes of the present approximate analysis are to quantify the surface radiance and its uncertainty due to measurement limitations. It is believed that there are scenarios within limited latitudinal zones, local times, and seasons where the assumed path characteristics are reasonably valid, and the error would be a small bias term to the calculated values.<>
{"title":"Limitations of triple-angle radiometric geosurface measurements from high altitude to mitigate low-absorption atmospheric effects","authors":"K. Tomiyasu, P. Dorian, P. Eitner","doi":"10.1109/COMEAS.1995.472336","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472336","url":null,"abstract":"The remote measurement of geosurface radiances using microwave and thermal infrared radiometers from satellite platforms has been an attractive and challenging goal. A significant impediment is data corruption by the intervening atmosphere. Attempts to correct for the atmosphere apparently have not been reported at microwave frequencies, but have been addressed at thermal infrared wavelengths. For thermal infrared, papers have been written reporting on multi-spectral and multi-angle measurements to infer the absolute value of geosurface temperature. A dual-angle radiometric technique to measure sea-surface temperature from an aircraft has been reported by Saunders. His technique made measurements at zenith angles near 0/spl deg/ and 60/spl deg/, and the reported absolute accuracies are 0.2 degree C. Since the path length was short with small path loss and insignificant path radiance, two unknowns are involved and measurements at two angles were sufficient for solution. As the platform altitude is increased, the number of significant factors increases, such as upwelling radiance from a lossy atmosphere and downwelling radiance scattered from the surface. With an increase in the number of significant factors, the number of independent measurements must also increase for solution. In this paper, an attempt is made to examine the utility of a triple-angle measurement method on the same area or pixel to extend the earlier dual-angle measurement technique. It is assumed that the next significant factor for some examples maybe the radiance from the intervening path. The purposes of the present approximate analysis are to quantify the surface radiance and its uncertainty due to measurement limitations. It is believed that there are scenarios within limited latitudinal zones, local times, and seasons where the assumed path characteristics are reasonably valid, and the error would be a small bias term to the calculated values.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121578877","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472344
K. Kozlov, A. I. Logvin
Considers the possibility of using radar and radiometry polarization methods for identifying the phase state of atmospheric precipitating particles. Methods for the statistical processing of experimental data are studied.<>
考虑了利用雷达和辐射偏振法识别大气沉淀粒子相态的可能性。研究了实验数据的统计处理方法。
{"title":"Differentiation of the phase state of hydrometeors by radiopolarimetric methods","authors":"K. Kozlov, A. I. Logvin","doi":"10.1109/COMEAS.1995.472344","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472344","url":null,"abstract":"Considers the possibility of using radar and radiometry polarization methods for identifying the phase state of atmospheric precipitating particles. Methods for the statistical processing of experimental data are studied.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"250 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124420928","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472342
A. K. Arakelian, V. Hambaryan
Discusses the spatially and temporally combined use of microwave radar and microwave radiometry for remote sensing. Wind speeds, SST and sea surface roughness applications are considered.<>
讨论了微波雷达与微波辐射测量技术在遥感中的时空结合应用。考虑了风速、海温和海面粗糙度的应用
{"title":"X-band Doppler-radar and radiometer system","authors":"A. K. Arakelian, V. Hambaryan","doi":"10.1109/COMEAS.1995.472342","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472342","url":null,"abstract":"Discusses the spatially and temporally combined use of microwave radar and microwave radiometry for remote sensing. Wind speeds, SST and sea surface roughness applications are considered.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114257253","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472343
F. Solheim
A temperature profiling radiometer based on a highly stable synthesizer, rather than traditionally used Gunn oscillators, has been designed and fabricated under contract to White Sands Missile Range. This profiler is capable of tuning a user-selected ensemble of frequencies in the range of 52.85 to 58.8 GHz as well as fixed water vapor and water channels at 25.8 and 31.4 GHz. This instrument weighs about 30 kg and consumes about 200 watts. Because of the frequency stability of the receiver, and because of the large number of observing frequencies possible, improved profile accuracy and resolution is expected over Gunn-based temperature profilers. An inexpensive, simple, and accurate calibration target system that includes the antenna system has been developed for this profiler. The calibration target can be loaded with liquid nitrogen or other cryogenic liquids. Tests with a Radiometrics water vapor radiometer have demonstrated stability of 0.1 K over 6 hours. The cryogenic liquid temperature can be known by its boiling point to within several hundredths of a Kelvin by a simple barometric pressure measurement. Preliminary design work has also been accomplished on a portable (35 kg) water vapor profiling radiometer. This radiometer is to utilize a stable synthesizer to map pressure broadening by tuning across the 22 GHz water vapor line.<>
{"title":"Microwave methods of atmospheric temperature and water vapor profiling","authors":"F. Solheim","doi":"10.1109/COMEAS.1995.472343","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472343","url":null,"abstract":"A temperature profiling radiometer based on a highly stable synthesizer, rather than traditionally used Gunn oscillators, has been designed and fabricated under contract to White Sands Missile Range. This profiler is capable of tuning a user-selected ensemble of frequencies in the range of 52.85 to 58.8 GHz as well as fixed water vapor and water channels at 25.8 and 31.4 GHz. This instrument weighs about 30 kg and consumes about 200 watts. Because of the frequency stability of the receiver, and because of the large number of observing frequencies possible, improved profile accuracy and resolution is expected over Gunn-based temperature profilers. An inexpensive, simple, and accurate calibration target system that includes the antenna system has been developed for this profiler. The calibration target can be loaded with liquid nitrogen or other cryogenic liquids. Tests with a Radiometrics water vapor radiometer have demonstrated stability of 0.1 K over 6 hours. The cryogenic liquid temperature can be known by its boiling point to within several hundredths of a Kelvin by a simple barometric pressure measurement. Preliminary design work has also been accomplished on a portable (35 kg) water vapor profiling radiometer. This radiometer is to utilize a stable synthesizer to map pressure broadening by tuning across the 22 GHz water vapor line.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123751929","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}
Pub Date : 1995-04-03DOI: 10.1109/COMEAS.1995.472350
Yingyin Zou, Chonghui Cheng
An improved procedure for the scattering from a perfectly conducting body is proposed, in which a complete expansion combining with finite difference scheme is used for the scattered fields from an arbitrary conducting body including sharp edges. Some numerical results verify the effectiveness of this improvement.<>
{"title":"The improvement of generalized multiple technique and its application in the scattering from perfectly conducting bodies with nonsmoothed surface","authors":"Yingyin Zou, Chonghui Cheng","doi":"10.1109/COMEAS.1995.472350","DOIUrl":"https://doi.org/10.1109/COMEAS.1995.472350","url":null,"abstract":"An improved procedure for the scattering from a perfectly conducting body is proposed, in which a complete expansion combining with finite difference scheme is used for the scattered fields from an arbitrary conducting body including sharp edges. Some numerical results verify the effectiveness of this improvement.<<ETX>>","PeriodicalId":274878,"journal":{"name":"Conference Proceedings Second Topical Symposium on Combined Optical-Microwave Earth and Atmosphere Sensing","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122371399","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：