11 research outputs found

    Intercomparison of spectroradiometers and Sun photometers for the determination of the aerosol optical depth during the VELETA-2002 field campaign

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    [ 1] In July 2002 the VELETA-2002 field campaign was held in Sierra Nevada ( Granada) in the south of Spain. The main objectives of this field campaign were the study of the influence of elevation and atmospheric aerosols on measured UV radiation. In the first stage of the field campaign, a common calibration and intercomparison between Licor-1800 spectroradiometers and Cimel-318 Sun photometers was performed in order to assess the quality of the measurements from the whole campaign. The intercomparison of the Licor spectroradiometers showed, for both direct and global irradiances, that when the comparisons were restricted to the visible part of the spectrum the deviations were within the instruments' nominal accuracies which allows us to rely on these instruments for measuring physical properties of aerosols at the different measurement stations. A simultaneous calibration on AOD data was performed for the Cimel-318 Sun photometers. When a common calibration and methodology was applied, the deviation was lowered to much less than 0.01 for AOD. At the same time an intercomparison has been made between the AOD values given by the spectroradiometers and the Sun photometers, with deviations obtained from 0.01 to 0.03 for the AOD in the visible range, depending on the channel. In the UVA range, the AOD uncertainty was estimated to be around 0.02 and 0.05 for Cimel and Licor respectively. In general the experimental differences were in agreement with this uncertainty estimation. In the UVB range the AOD measurements should not be used due to maximum instrumental uncertainties

    Ceres Scales Ground Validation Campaigns for Gerb. Assessment of the Valencia Anchor Station Capabilities

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    Proceedings del 3rd MSG RAO Workshop, celebrado el 15 de junio de 2006 en Helsinki, Finlandia.The Valencia Anchor Station (VAS) was set up by the University of Valencia at the natural region of UtielRequena Plateau in 2001. The plateau is a large and reasonably homogeneous area suitable for validation of low spatial resolution satellite data and products such as GERB's. In the framework of the EUMETSAT/ESA MSG-RAO Project no. 138 GIST Proposal for Calibration/Validation of SEVIRI and GERB, and of the Spanish Research Programme on Space Project SCALES (SEVIRI & GERB Cal/Val Area for Largescale Field ExperimentS), three GERB ground validation campaigns have so far been carried out at the VAS under different land surface conditions. CERES instruments onboard NASA EOS Aqua and Terra satellites, operating in PAPS (Programmable Azimuth Plane Scanning) mode, have generously provided additional SW and LW radiance measurements to support validation efforts. These have shown to be most valuable as intermediate validation step between ground measurements and the large GERB pixel size

    Intercomparison of spectroradiometers and Sun photometers for the determination of the aerosol optical depth during the VELETA-2002 field campaign

    Get PDF
    [ 1] In July 2002 the VELETA-2002 field campaign was held in Sierra Nevada ( Granada) in the south of Spain. The main objectives of this field campaign were the study of the influence of elevation and atmospheric aerosols on measured UV radiation. In the first stage of the field campaign, a common calibration and intercomparison between Licor-1800 spectroradiometers and Cimel-318 Sun photometers was performed in order to assess the quality of the measurements from the whole campaign. The intercomparison of the Licor spectroradiometers showed, for both direct and global irradiances, that when the comparisons were restricted to the visible part of the spectrum the deviations were within the instruments' nominal accuracies which allows us to rely on these instruments for measuring physical properties of aerosols at the different measurement stations. A simultaneous calibration on AOD data was performed for the Cimel-318 Sun photometers. When a common calibration and methodology was applied, the deviation was lowered to much less than 0.01 for AOD. At the same time an intercomparison has been made between the AOD values given by the spectroradiometers and the Sun photometers, with deviations obtained from 0.01 to 0.03 for the AOD in the visible range, depending on the channel. In the UVA range, the AOD uncertainty was estimated to be around 0.02 and 0.05 for Cimel and Licor respectively. In general the experimental differences were in agreement with this uncertainty estimation. In the UVB range the AOD measurements should not be used due to maximum instrumental uncertainties

    Surgical treatment for colorectal cancer: Analysis of the influence of an enhanced recovery programme on long-term oncological outcomes-a study protocol for a prospective, multicentre, observational cohort study

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    Introduction The evidence currently available from enhanced recovery after surgery (ERAS) programmes concerns their benefits in the immediate postoperative period, but there is still very little evidence as to whether their correct implementation benefits patients in the long term. The working hypothesis here is that, due to the lower response to surgical aggression and lower rates of postoperative complications, ERAS protocols can reduce colorectal cancer-related mortality. The main objective of this study is to analyse the impact of an ERAS programme for colorectal cancer on 5-year survival. As secondary objectives, we propose to analyse the weight of each of the predefined items in the oncological results as well as the quality of life. Methods and analysis A multicentre prospective cohort study was conducted in patients older than 18 years of age who are scheduled to undergo surgery for colorectal cancer. The study involved 12 hospitals with an implemented enhanced recovery protocol according to the guidelines published by the Spanish National Health Service. The intervention group includes patients with a minimum implementation level of 70%, and the control group includes those who fail to reach this level. Compliance will be studied using 18 key performance indicators, and the results will be analysed using cancer survival indicators, including overall survival, cancer-specific survival and relapse-free survival. The time to recurrence, perioperative morbidity and mortality, hospital stay and quality of life will also be studied, the latter using the validated EuroQol Five questionnaire. The propensity index method will be used to create comparable treatment and control groups, and a multivariate regression will be used to study each variable. The Kaplan-Meier estimator will be used to estimate survival and the log-rank test to make comparisons. A p value of less than 0.05 (two-tailed) will be considered to be significant. Ethics and dissemination Ethical approval for this study was obtained from the Aragon Ethical Committee (C.P.-C.I. PI20/086) on 4 March 2020. The findings of this study will be submitted to peer-reviewed journals (BMJ Open, JAMA Surgery, Annals of Surgery, British Journal of Surgery). Abstracts will be submitted to relevant national and international meetings. Trial registration number NCT04305314
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