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Intensity modulated radiotherapy (IMRT) is one of the most modern radiation therapy treatment techniques. Although IMRT can deliver high and complex conformational doses to the tumor volume, its implementation requires rigorous quality assurance (QA) procedures that include a dosimetric pre-treatment verification of individual patient planning. This verification usually involves measuring a small volume of absolute dose with an ionization chamber and checking bi-dimensional fluency with an array of detectors. The planning technique has tri-dimensional characteristics, but no tridimensional dosimetry has been established in the clinical routine. One strategy to perform three-dimensional dosimetry is to use polymeric gels associated with magnetic resonance imaging to evaluate dose distribution. Here, we have compared the results of conventional QA procedures involving one- and two-dimensional dosimetry to the results of three-dimensional dosimetry conducted with MAGIC-f gel in 10 cases of prostate cancer IMRT planning. More specifically, we used the gamma index (3%/3mm) to compare the results of three-dimensional dosimetry to the expected dose distributions obtained with the treatment planning system. Except for one IMRT treatment plan, the gel dosimetry results agreed with the conventional quality control and provided an overview of dose distribution in the target volume.

Purpose To introduce and evaluate a method developed for the direct measurement of mammographic x-ray spectra using a CdTe spectrometer. The assembly of a positioning system and the design of a simple and customized alignment device for this application is described. Methods A positioning system was developed to easily and accurately locate the CdTe detector in the x-ray beam. Additionally, an alignment device to line up the detector with the central axis of the radiation beam was designed. Direct x-ray spectra measurements were performed in two different clinical mammography units and the measured x-ray spectra were compared with computer-generated spectra. In addition, the spectrometer misalignment effect was evaluated by comparing the measured spectra when this device is aligned relatively to when it is misaligned. Results The positioning and alignment of the spectrometer have allowed the measurements of direct mammographic x-ray spectra in agreement with computer-generated spectra. The most accurate x-ray spectral shape, related with the minimal HVL value, and high photon fluence for measured spectra was found with the spectrometer aligned according to the proposed method. The HVL values derived from both simulated and measured x-ray spectra differ at most 1.3 and 4.5% for two mammography devices evaluated in this study. Conclusion The experimental method developed in this work allows simple positioning and alignment of a spectrometer for x-ray spectra measurements given the geometrical constraints and maintenance of the original configurations of mammography machines.

RESUMEN Objetivo Comparar la motilidad de la columna cervical durante la realizacion de laringoscopia directa utilizando hoja Miller con proteccion cervical, triple maniobra e intubacion con estilete luminoso en pacientes sin predictores de via aerea dificil. Metodos Serie de casos de 5 pacientes femeninas sometidas a embolizacion electiva de malformaciones arteriovenosas cerebrales, entre enero y marzo de 2003, atendidas en el Hospital Universitario Fundacion Santa Fe, de Bogota. Se realizaron mediciones bajo videofuoroscopia para determinar el desplazamiento angular de la columna cervical. Resultado Las 5 mujeres incluidas tenian una edad promedio de 43 anos. Los puntos de mayor movimiento fueron C1 y C5. Se obtuvieron valores basales con la cabeza del paciente en posicion neutra para comparar las demas mediciones. Se observo una menor movilidad en los puntos de mayor movimiento (C1 y C5) con la utilizacion del estilete luminoso, en comparacion con la laringoscopia directa con hoja Miller (8° vs. 13,2° en C1, y 6,4° vs. 15,6° en C5). La realizacion de la triple maniobra y la fijacion del tubo endotraqueal produjeron angulaciones menores, comparadas con las producidas durante las maniobra de intubacion. Conclusion La intubacion con estilete luminoso podria ser una alternativa util y segura en pacientes con trastornos de la columna cervical en quienes existen limitaciones para la movilizacion de esta.

185 p. Las cepas de un viñedo suelen plantarse en zonas con características similares, sin embargo, las uvas producidas en cada cepa difieren en calidad y cantidad. Para lograr los objetivos planteados por un viticultor, como calidad de mosto, cantidad de uva, etc., es recomendable adoptar sistemas que permitan gestionar los métodos de producción. El objetivo de este trabajo fue identificar las variables vitivinícolas adecuadas para hacer un seguimiento continuo de viñedos e implantar un sistema de viticultura de precisión, usando teledetección y sistemas de información geográfica. Para ello se midieron variables relacionadas con la calidad, producción y vigor de las cepas en cuatro viñedos diferentes (Cabernet Sauvignon, Mencía, Merlot y Tempranillo), localizadas en la Denominación de Origen Bierzo, desde el año 2007 al 2012. Además, se estimó el contenido en agua de las hojas mediante espectroradiometría de campo. Los resultados mostraron una mayor variabilidad inter-anual que inter-varietal de las variables de calidad, producción y vigor. El comienzo de los estados fenológicos indicó que cada variedad requiere condiciones climáticas distintas, pero no condicionan la estabilidad de cada variable dentro de la viña. Mencía mostró los mejores valores de calidad y producción mientras que Tempranillo obtuvo los mayores valores de vigor. La delineación de dos zonas de manejo diferenciado para cada viñedo, se realizó mediante interpolación por krigeado ordinario y clasificación cluster (ISODATA), teniendo en cuenta variables de calidad, producción, vigor y suelo de las parcelas. La clasificación más adecuada fue la definida por los sólidos solubles totales, acidez total, índice de polifenoles, pH, peso medio del racimo y longitud del entrenudo. No se lograron mejorar las exactitudes al añadir variables relativas a las características del suelo en las clasificaciones. En el análisis de exactitud de la zonificación se obtuvieron los mejores resultados para la variedad Mencía y los peores para Tempranillo (exactitud global 45,24% y 14,28% respectivamente). Utilizando un espectroradiómetro de campo se estimó el contenido en agua de las hojas de forma rápida, eficaz y no destructiva. Con los datos espectrales tomados a nivel de hoja y de cubierta se calcularon índices de vegetación (VI) y se aplicó continuum removal (CR) en cuatro tramos del espectro. Los modelos ajustados mediante regresión por mínimos cuadrados parciales (PLSR) fueron más exactos que los que utilizaron regresión de mínimos cuadrados ordinaria (OLSR). El modelo más adecuado se obtuvo usando PLSR en el espectro normalizado por CR en el intervalo comprendido entre de 1265 nm a 1668 nm (R2 = 0,675 y RMSE = 0,014). Mediante sistemas de información geográfica se ha logrado establecer una zonificación de los viñedos basada en variables que habitualmente sirven para el seguimiento del desarrollo anual de la vid. La zonificación permitirá aplicar un manejo diferenciado de cada agrupamiento permitiendo optimizar los inputs utilizados en cada zona. El espectroradiómetro de campo ha permitido estimar el contenido en agua foliar a partir de reflectancias, mediante métodos rápidos, fiables y no destructivos. Por tanto, en este trabajo se ha demostrado la utilidad de los sistemas de información geográfica y de la teledetección de alta resolución espectral como herramientas de ayuda a la viticultura de precisión

This paper provides a wrap-up of some of the activities undertaken by SMOS L1 team to fine tune the instrument calibration and modeling that eventually has resulted into a SMOS full-polarimetric measurement and image reconstruction enhanced performance

OBJETIVO: propor método de avaliação e manutenção da eficiência dos equipamentos mais comumente usados em nosso meio, de maneira a uniformizar os resultados obtidos em tratamentos fototerápicos por diferentes serviços. MATERIAL E MÉTODOS: o radiômetro/fotômetro utilizado na medida da irradiância espectral é de fabricação nacional e atende aos requisitos básicos indispensáveis. As padronizações de medida procuram ser facilmente aplicáveis e reprodutíveis aos aparelhos de fototerapia em uso no país. O material necessário às aferições, excetuando-se o radiômetro, pode ser facilmente confeccionado em qualquer serviço de neonatologia. Procuramos nos trabalhos publicados nos últimos 10 anos no Medline os pertinentes a esta revisão. RESULTADO: propõe-se que a irradiância relatada nos trabalhos de fototerapia seja fornecida como Irradiância Espectral Média e descreve-se como obtê-la, tanto em fototerapias com fontes fluorescentes como halógenas. COMENTÁRIOS: são descritos os componentes dos radiômetros/fotômetros, cuja compreensão é importante para que possamos perceber variações na sensibilidade e diferenças significativas na irradância quando as faixas de leitura dos radiômetros são um pouco diferentes. A adoção de um tipo de equipamento padrão facilitaria muito a comparação de resultados obtidos por diferentes serviços. São ainda comentadas as características de diferentes equipamentos de fototerapia que podem interferir na mensuração da irradiância dos mesmos. OBJECTIVE: to propose a method to evaluate and maintain the efficiency of equipment commonly used in Brazil in order to obtain uniform results in phototherapy treatments in different services. MATERIAL AND METHODS: the radiometer/photometer used to measure spectral irradiance is locally manufactured and fulfills basic requirements. Measure standardization seeks to be applicable and reproducible to phototherapy devices employed in Brazil. The material necessary for measurements can be easily assembled by the neonatology staff, except for the radiometer. We searched Medline for papers relevant to this review published throughout the last 10 years. RESULTS: irradiance in phototherapy issues should be referred to as "medium spectral irradiance". We describe how to obtain medium spectral irradiance using fluorescent and halogen phototherapies. COMMENTS: the components of a radiometer/photometer are described. This knowledge is fundamental to understanding sensibility variations and to justifying differences in irradiance when ranges of radiometer recording are a little different. The standardization of this device will certainly simplify the comparison between results in different services. We also analyzed characteristics of different equipment used in phototherapy that might interfere with their irradiance.

This paper develops an analysis of the SAR impulse response function from the interferometric point of view, with the intention of studying its phase behavior in the presence of high squint angle values. It will be pointed out that in this case, a phase ramp is present in the range direction, which, in combination with a certain degree of misregistration between the two images induces an offset in the generated interferometric phase. This behavior, if not compensated, imposes strong limits on the performance of the interferometric techniques in a squinted case, especially for airborne SAR systems. The article proposes two new techniques, which are appropriate to correct the phase bias coming from this source. The first one is based on a modification of the azimuth compression filter, which cancels the phase ramp of the range impulse response function for one specific squint value. In case the SAR processing is performed with variable squint over range, the authors propose a second method oriented to estimating the expected misregistration and thus, the phase bias by means of an iterative approach. Simulated data as well as real corner reflector responses are used to show that the correct topography can be recovered precisely even in the presence of phase bias coming from the squinted geometry.

Rapidly developing unmanned aerial vehicles (UAV) have provided the remote sensing community with a new rapidly deployable tool for small area monitoring. The progress of small payload UAVs has introduced greater demand for light weight aerial payloads. For applications requiring aerial images, a simple consumer camera provides acceptable data. For applications requiring more detailed spectral information about the surface, a new Fabry-Perot interferometer based spectral imaging technology has been developed. This new technology produces tens of successive images of the scene at different wavelength bands in very short time. These images can be assembled in spectral data cubes with stereoscopic overlaps. On field the weather conditions vary and the UAV operator often has to decide between flight in sub optimal conditions and no flight. Our objective was to investigate methods for quantitative radiometric processing of images taken under varying illumination conditions, thus expanding the range of weather conditions during which successful imaging flights can be made. A new method that is based on insitu measurement of irradiance either in UAV platform or in ground was developed. We tested the methods in a precision agriculture application using realistic data collected in difficult illumination conditions. Internal homogeneity of the original image data (average coefficient of variation in overlapping images) was 0.14–0.18. In the corrected data, the homogeneity was 0.10–0.12 with a correction based on broadband irradiance measured in UAV, 0.07–0.09 with a correction based on spectral irradiance measurement on ground, and 0.05–0.08 with a radiometric block adjustment based on image data. Our results were very promising, indicating that quantitative UAV based remote sensing could be operational in diverse conditions, which is prerequisite for many environmental remote sensing applications.

This paper presents the characterization in terms of spatial resolution and radiometric sensitivity of a W-band Total Power Radiometer (TPR). The TPR is based on a heterodyne receiver with 64 dB of gain and 6.5 dB of noise figure. An antenna system consisting on a pan-tilt scanner has been designed and built in order to aim a 100 mm offset parabolic reflector. With this system, relative temperature images of targets at a 1 m standoff range are obtained in indoor environments with an spatial resolution of 4 cm.

OBJETIVO: Determinar exposições decorrentes da radioiodoterapia ambulatorial do carcinoma diferenciado da tireoide (CDT) sobre os familiares dos pacientes e o meio ambiente. MÉTODOS: Administraram-se 100 a 150 mCi de (131I)NaI para tratamento ambulatorial de 20 pacientes com CDT. Monitorizaram-se com dosímetros termoluminescentes as doses de radiação recebidas por familiares (n = 27) e potenciais de dose nas residências. Também foram monitorizadas contaminação de superfície e rejeitos radioativos. RESULTADOS: Registraram-se doses < 1,0 mSv em 26 acompanhantes e 2,8 mSv em um caso, inferiores ao aceitável para exposições médicas (5,0 mSv/procedimento). Excetuando-se o quarto dos pacientes (média = 0,69 mSv), determinou-se potencial de dose nas residências < 0,25 mSv. A contaminação de superfícies (4,2 Bq.cm-2) não ultrapassou níveis de liberação, sem representar riscos mesmo em simulações do pior cenário. Os rejeitos radioativos tiveram volume de 2,5 litros e atividade estimada em 90 µCi (média = 4,5 µCi/paciente). CONCLUSÕES: Não foi constatado impacto radiológico ao meio ambiente ou aos familiares de pacientes tratados ambulatorialmente com 100 a 150 mCi de iodo-131 e acompanhados por profissionais qualificados. PURPOSE:To evaluate exposure and dosimetry to family members and environment due to outpatient radioiodine therapy of differentiated thyroid carcinoma. METHODS: Twenty patients were treated with 100-150mCi of iodine-131 on an out-patient basis. Family members dosimetry (n = 27) and potential doses inside the house were measured with thermoluminescent dosimeters. Surface contamination and radioactive wastes were also monitored. RESULTS: Less than 1.0 mSv doses were found in 26 co-habitants and 2.8 mSv in a single case (inferior to the acceptable value of 5.0 mSv/procedure). Potential doses in the houses were inferior to 0.25 mSv, excluding the patients bedroom (mean value = 0.69 mSv). Surface contamination (mean = 4.2 Bq.cm-2) were below clearance levels. Radioactive wastes generated had a volume of 2.5 liters and a total activity estimated in 90 µCi, with a calculated exposure close to the background radiation levels. CONCLUSIONS: No radiological impact was detected after iodine therapy with 100-150 mCi on an out-patient basis followed by experienced professionals.

Speckle noise represents one of the major problems when synthetic aperture radar (SAR) data are considered. Despite the fact that speckle is caused by the scattering process itself, it must be considered as a noise source due to the complexity of the scattering process. The presence of speckle makes data interpretation difficult, but it also affects the quantitative retrieval of physical parameters. In the case of one-dimensional SAR systems, speckle is completely determined by a multiplicative noise component. Nevertheless, for multidimensional SAR systems, speckle results from the combination of multiplicative and additive noise components. This model has been first developed for single-look data. The objective of this paper is to extend the single-look data model to define a multilook multidimensional speckle noise model. The asymptotic analysis of this extension, for a large number of averaged samples, is also considered to assess the model properties. Details and validation of the multilook multidimensional speckle noise model are provided both theoretically and by means of experimental SAR data acquired by the experimental synthetic aperture radar system, operated by the German Aerospace Center.

Sea surface salinity can be remotely measured by means of L-band microwave radiometry. However, the brightness temperature also depends on the sea surface temperature and on the sea state, which is probably today one of the driving factors in the salinity retrieval error budgets of the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) mission and the NASA-Comision Nacional de Actividades Espaciales Aquarius/SAC-D mission. This paper describes the Passive Advanced Unit (PAU) for ocean monitoring. PAU combines in a single instrument three different sensors: an L-band radiometer with digital beamforming (DBF) (PAU-RAD) to measure the brightness temperature of the sea at different incidence angles simultaneously, a global positioning system (GPS) reflectometer [PAU-reflectometer of Global Navigation Satellite Signals (GNSS-R)] also with DBF to measure the sea state from the delay-Doppler maps, and two infrared radiometers to provide sea surface temperature estimates. The key characteristic of this instrument is that both PAU-RAD and the PAU-GNSS/R share completely the RF/IF front-end, and analog-to-digital converters. Since in order to track the GPS-reflected signal, it is not possible to chop the antenna signal as in a Dicke radiometer, a new radiometer topology has been devised which makes uses of two receiving chains and a correlator, which has the additional advantage that both PAU-RAD and PAU-GNSS/R can be operated continuously and simultaneously to perform the sea-state corrections of the brightness temperature. This paper presents the main characteristics of the different PAU subsystems, and analyzes in detail the PAU-radiometer concept.

The PLANCK mission of the European Space Agency is devoted to produce sky maps of the cosmic microwave background radiation. The low-frequency instrument is a wide-band cryogenic microwave radiometer array operating at 30, 44, and 70 GHz. The design, test techniques, and performance of the complete differential radiometer at 30 GHz are presented. This elegant breadboard 30-GHz radiometer is composed of a front-end module (FEM) assembled at the Jodrell Bank Observatory, Cheshire, U.K., and a back-end module assembled at the Universidad de Cantabria, Cantabria, Spain, and Telecomunicacio/spl acute/, Universitat Polite/spl acute/cnica de Catalunya, Barcelona, Spain. The system noise temperature was excellent, mainly due to the very low noise performance of the FEM amplifiers, which achieved an average noise temperature of 9.4 K.

OBJETIVO: propor metodo de avaliacao e manutencao da eficiencia dos equipamentos mais comumente usados em nosso meio, de maneira a uniformizar os resultados obtidos em tratamentos fototerapicos por diferentes servicos. MATERIAL E METODOS: o radiometro/fotometro utilizado na medida da irradiância espectral e de fabricacao nacional e atende aos requisitos basicos indispensaveis. As padronizacoes de medida procuram ser facilmente aplicaveis e reprodutiveis aos aparelhos de fototerapia em uso no pais. O material necessario as afericoes, excetuando-se o radiometro, pode ser facilmente confeccionado em qualquer servico de neonatologia. Procuramos nos trabalhos publicados nos ultimos 10 anos no Medline os pertinentes a esta revisao. RESULTADO: propoe-se que a irradiância relatada nos trabalhos de fototerapia seja fornecida como Irradiância Espectral Media e descreve-se como obte-la, tanto em fototerapias com fontes fluorescentes como halogenas. COMENTARIOS: sao descritos os componentes dos radiometros/fotometros, cuja compreensao e importante para que possamos perceber variacoes na sensibilidade e diferencas significativas na irradância quando as faixas de leitura dos radiometros sao um pouco diferentes. A adocao de um tipo de equipamento padrao facilitaria muito a comparacao de resultados obtidos por diferentes servicos. Sao ainda comentadas as caracteristicas de diferentes equipamentos de fototerapia que podem interferir na mensuracao da irradiância dos mesmos.

In Earth observation programs there is a need of passive low frequency (L-band) measurements to monitor soil moisture and ocean salinity with high spatial resolution 10-20 km, a radiometric resolution of 1 K and a revisit time of 1-3 days. Compared to total power radiometers aperture synthesis interferometric radiometers are technologically attractive because of their reduced mass and hardware requirements. In this field it should be mentioned the one-dimensional (1D) linear interferometer ESTAR developed by NASA and MIRAS a two-dimensional (2D) Y-shaped interferometer currently under study by European Space Agency (ESA). Interferometer radiometers measure the correlation between pairs of nondirective antennas. Each complex correlation is a sample of the “visibility” function which, in the ideal case, is the spatial Fourier transform of the brightness temperature distribution. Since most receiver phase and amplitude errors can be hardware calibrated, Fourier based iterative inversion methods will be useful when antenna errors are small, their radiation voltage patterns are not too different, and mutual coupling is small. In order to minimize on-board hardware requirements-antennas, receivers and correlators-the choice of the interferometer array shape is of great importance since it determines the (u,v) sampling strategy and the minimum number of visibility samples required for a determined aliasing level. In this sense, Y-shaped and triangular-shaped arrays with equally spaced antennas are optimal. The main contribution of this paper is a technique that allows the authors to process the visibility samples over the hexagonal sampling grids given by Y-shaped and triangular-shaped arrays with standard rectangular FFT routines. Since no interpolation processes are involved, the risk of induced artifacts in the recovered brightness temperature over the wide held of view required in Earth observation missions is minimized and signal to noise ratio (SNR) is preserved.

The fundamental concept of interferometric aperture synthesis microwave radiometry for Earth observation is reviewed. The measurement principles and a discussion on the signal processing techniques for image reconstruction are briefly summarized. Examples of real measurements from the sensor onboard the ESA SMOS mission are used to illustrate the image reconstruction techniques.

In recent years Global Navigation Satellite System’s signals Reflectometry (GNSS-R) has stood as a potential powerful remote sensing technique to derive scientifically relevant geophysical parameters such as ocean altimetry, sea state or soil moisture. This has brought out the need of designing and implementing appropriate receivers in order to track and process this kind of signals in real-time to avoid the storage of huge volumes of raw data. This paper presents the architecture and performance of the Global Positioning System (GPS) Reflectometer Instrument for PAU (griPAU), a real-time high resolution Delay-Doppler Map reflectometer, operating at the GPS L1 frequency with the C/A codes. The griPAU instrument computes 24 x 32 complex points DDMs with configurable resolution (DfDmin = 20 Hz, Dsmin = 0.05 chips) and selectable coherent (minimum = 1 ms, maximum = 100 ms for correlation loss Dq < 90%)and incoherent integration times (minimum of one coherent integration period and maximum not limited but typically

The design of a 94 GHz Total Power Radiometer system for imaging purposes is presented in this paper. A mechanical beam-scanning antenna system is used to acquire passive raster images. The main performance parameters of the imaging system are described as well as their impact on the resulting image quality. A temperature resolution below 1K and a spatial resolution around 4 cm at 1 meter standoff distance are obtained with this system. Moreover, radiometric images acquired in indoor and outdoor environments are shown and compared.