- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Workshop on Lunar Calibration for Satellite Remote Sensing
摘要： Tracking climate variables at the levels of precision and accuracy required to detect global change requires satellite sensors to make highly consistent measurements that can be compared to measurements made at different times and with different instruments. Gaps in climate data records, such as those resulting from launch delay or instrument failure, and inconsistencies in radiometric scales between satellites can introduce unnecessary measurement error and thus undermine the credibility of fundamental climate data records. To address these issues, leading experts in satellite remote sensing and lunar observation and modeling assembled at the National Institute of Standards and Technology from 12-15 May 2012 for a workshop to discuss the utility of and strategies for using the Moon to calibrate satellite remote sensing measurements. This report summarizes the outcome of the workshop, including suggested steps to maximize the value of the Moon as an exoatmospheric calibration source for satellite remote sensing.
关键词： lunar spectral irradiance,remote sensing,calibration,moon,radiometry
更新于2025-09-09 09:28:46
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Analysis of the Effect of Soil Roughness in the Forward-Scattering Interference Pattern Using Second-Order Small Perturbation Method Simulations
摘要： Soil moisture (SM) is a key geophysical variable that can be estimated at regional scales using remote sensing techniques, by making use of the known relationship between soil re?ectivity and the dielectric constant in the microwave regime. In this context, the exploitation of available illuminators of opportunity that currently emit large amounts of power at microwave frequencies (compared to typical synthetic aperture radar systems) is promising. Some published techniques estimate SM by analyzing the interference pattern (IP) between direct and re?ected signal as measured by a single antenna (i.e., IP technique). In this letter, a new approach to simulate the IP is proposed, in which the soil roughness is modeled straightforwardly using the second-order small perturbation model. Results illustrate that the “notch” in the VV-polarization IP (related to the Brewster angle) can only be directly observed for very low values of soil rms roughness (s < 0.5 cm). For typical values of soil roughness (s ～ 1.2 cm), the notch disappears and only a minimum in the IP is observed near the Brewster angle.
关键词： Electromagnetic and remote sensing,microwave radiometry,Global Navigation Satellite System data,surface and subsurface properties
更新于2025-09-09 09:28:46
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ELECTROMAGNETIC SIGNATURES OF HUMAN SKIN IN THE MILLIMETER WAVE BAND 80-100 GHZ
摘要： Due to changes in global security requirements attention is turning to new means by which anomalies on the human body might be identi?ed. For security screening systems operating in the millimeter wave band anomalies can be identi?ed by measuring the emissivities of subjects. As the interaction of millimeter waves with the human body is only a fraction of a millimeter into the skin and clothing has a small, but known e?ect, precise measurement of the emission and re?ection of this radiation will allow comparisons with the norm for that region of the body and person category. A technique to measure the human skin emissivity in vivo over the frequency band 80 GHz to 100 GHz is developed and described. The mean emissivity values of the skin of a sample of 60 healthy participants (36 males and 24 females) measured using a 90 GHz calibrated radiometer were found to range from 0.17±0.005 to 0.68±0.005. The lower values of emissivity are a result of measuring particularly thin skin on the inner wrist, volar side of the forearm, and back of hand, whereas higher values of emissivity are results of measuring thick skin on the outer wrist, dorsal surface of the forearm, and palm of hand. The mean di?erences in the emissivity between Asian and European male participants were calculated to be in the range of 0.04 to 0.11 over all measurement locations. Experimental measurements of the emissivity for male and female participants having normal and high body mass index indicate that the mean di?erences in the emissivity are in the range of 0.05 to 0.15 for all measurement locations. These results show the quantitative variations in the skin emissivity between locations, gender, and individuals. The mean di?erences in the emissivity values between dry and wet skin on the palm of hand and back of hand regions were found to be 0.143 and 0.066 respectively. These results con?rm that radiometry can, as a non-contact method, identify surfaces attached to the human skin in tens of seconds. These results indicate a route to machine anomaly detection that may increase the through-put speed, the detection probabilities and reduce the false alarm rates in security screening portals.
关键词： radiometry,security screening,emissivity,human skin,millimeter wave
更新于2025-09-04 15:30:14
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Operation and Development of a Center for Collective Use in the Field of Photonics
摘要： Management and procedural principles underlying the operation and development of the Center for Collective Use of high-precision measurement technologies in the field of photonics for the purpose of assuring equal access of scientists to expensive research and measurement complexes, scientific equipment, and plants are set forth. A number of different procedural approaches to assuring an exhaustive integral supply of the Center for Collective Use with scientific equipment are considered using as an example the creation of a measurement and calibration complex for metrological assurance of measurements in the field of microwave photonics.
关键词： photometry,system for remote sensing of the Earth,center for collective use,radio photonic channel,spectroradiometry,optical radiometry,photonics
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Predicting Mean Radiative Temperature at Millimeter Wavelengths in Continental Climate Areas
摘要： The aim of this work is to present a parametric model for the prediction of the down-welling mean radiative temperature (Tmr) in the microwave region. For the model set-up, the Sky Noise Eddington Model has been exploited to generate a synthetic clouds dataset driven by radiosounding observations. The core of the model, developed in continental climate areas, is the normalization of Tmr for the surface temperature (TS) of the geographic area of interest that makes the Tmr/TS model applicable in each site belonging to the considered climatic area. Retrieval of the predicted Tmr can be done by multiplying the Tmr/TS obtained from the parametric model at the considered attenuation value for the average TS. The model parameters depend on frequency and elevation angle within the range from 23.8 GHz to 49.5 GHz and from 90° to 5°, respectively. A preliminary verification of the model is accomplished, at 23.8 GHz and 31.4 GHz, exploiting Sun-tracking radiometric measurements available in Rome (NY, USA) with promising results: RMSE never exceeds 0.02 and 0.1 at 23.8 GHz and 31.4 GHz, respectively.
关键词： Mean radiative temperature,microwave radiometry,Atmospheric radio-propagation
更新于2025-09-04 15:30:14
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Effect of a Thin DRY Snow Layer on the Lake ICE Thickness Measurement using Wideband Autocorrelation Radiometry
摘要： Wideband autocorrelation radiometry (WiBAR) is a new method to remotely sense the microwave propagation time τdelay of multi-path microwave emission of low loss layered surfaces such as dry snowpack and freshwater lake ice pack. The microwave propagation time τdelay through the pack yields a measure of its vertical extent; thus, this technique is a direct measurement of depth. However, the presence of a different low loss layer on the lake ice pack such as dry snow pack introduces another multi-path interference, which can effect the lake ice pack thickness measurement. We present a simple geophysical forward model for the multipath interference phenomenon and derive the WiBAR system requirements needed to correctly measure the ice pack thickness. An X-band instrument fabricated from commercial-off-the-shelf (COTS) components are used to measure the thickness freshwater lake ice at the University of Michigan Biological Station. Ice thickness retrieval is demonstrated from nadir to 73.9?.
关键词： Snowpack,autocorrelation,icepack,microwave radiometry,remote sensing
更新于2025-09-04 15:30:14
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Precipitation Retrieval Accuracies of the Tropics Constellation of Passive Microwave Cubesats
摘要： This paper evaluates the performance of the passive microwave spectrometer to be launched aboard the Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) for retrieving surface precipitation and hydrometeor water paths. The retrieval algorithms employ neural networks trained and evaluated using the physical reference model NCEP/WRF/TBSCAT/F(λ). Results show that TROPICS retrieved surface precipitation rates and hydrometeor water paths agree well with WRF truth. The accuracies of TROPICS retrieved daily, weekly, and monthly surface precipitation amounts are close to those of the Advanced Microwave Sounding Unit (AMSU). The TROPICS constellation will provide useful precipitation retrievals at unprecedented 30-minute temporal resolution.
关键词： CubeSat,microwave radiometry,TROPICS,AMSU,precipitation retrieval
更新于2025-09-04 15:30:14
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Spectral indices for the detection of salinity effects in melon plants
摘要： Water scarcity and soil salinization affect large semiarid agricultural areas throughout the world. The maintenance of agricultural productivity implies better agricultural practices and a careful selection of resistant crops. A proper monitoring of the physiological status of plants can lead to better knowledge of plant nutritional requirements. Visible and near-infrared (VNIR) radiometry provides a non-destructive and quantitative method to monitor vegetation status by quantifying chemical properties using spectroscopic techniques. In this study, the capability of VNIR spectral measurements to detect salinity effects on melon (Cucumis melo L.) plants was tested. Melon plants were cultivated under multiple soil salinity conditions (electrical conductivity, (EC)1:5: 0.5, 1.0 and 2.5 dS m–1). Spectral data of leaves were transformed into vegetation indices indicative of the physiological status of the plants. The results showed differences for N (p < 0.05), K and Na content (p < 0.01) due to salinity suggesting different degrees of salt stress on the plants. Specific leaf area increased with salinity levels (p < 0.001). The capabilities of VNIR radiometry to assess the influence of soil salinity on melon physiology using a non-destructive method were demonstrated. A normalized difference vegetation index (NDVI750-705), and the ratio between water index (WI) and normalized difference vegetation index (WI/NDVI750-705) showed significant relationships (p < 0.01) with the salinity. Therefore, this method could be used for in-situ early detection of salinity stress effects.
关键词： VNIR radiometry,Cucumis melo L.,saline soil
更新于2025-09-04 15:30:14