کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6345628 | 1621225 | 2016 | 20 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Uncertainty assessment of surface net radiation derived from Landsat images
ترجمه فارسی عنوان
ارزیابی نااطمینی از تابش خالص سطح حاصل از تصاویر لندست
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کلمات کلیدی
تجزیه و تحلیل عدم قطعیت، تابش خالص، دمای سطح، آلبدو، تابش اشعه، لندست، مقیاس منطقه ای، البته دوره
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
کامپیوتر در علوم زمین
چکیده انگلیسی
Primary information describing the surface is derived from remote sensing observations. Surface albedo is estimated from spectral reflectances using a narrow-to-broadband conversion method. Land surface temperature is retrieved from top of canopy brightness temperature by accounting for land surface emissivity and reflection of atmospheric radiation; and emissivity is estimated using a relationship with a vegetation index and a spectral database of soil and plant canopy properties in the study area. The net radiation uncertainty is assessed using comparison with ground measurements over the Crau-Camargue and lower Rhone valley regions in France. We found Root Mean Square Errors between retrievals and field measurements of 0.25-0.33 (14-19%) for albedo, ~ 1.7 K for surface temperature and ~ 20 W·mâ 2 (5%) for net radiation. Results show a substantial underestimation of Landsat-7 albedo (up to 0.024), particularly for estimates retrieved using the middle infrared, which could be due to different sources: the calibration of field sensors, the correction of radiometric signals from Landsat-7 or the differences in spectral bands with the sensors for which the models where originally derived, or the atmospheric corrections. We report a global uncertainty in net radiation of 40-100 W·mâ 2 equally distributed over the shortwave and longwave radiation, which varies spatially and temporally depending on the land use and the time of year. In situ measurements of incoming shortwave and longwave radiation contribute the most to uncertainty in net radiation (10-40 W·mâ 2 and 20-30 W·mâ 2, respectively), followed by uncertainties in albedo (< 25 W·mâ 2) and surface temperature (~ 8 W·mâ 2). For the latter, the main factors were the uncertainties in top of canopy reflectances (< 10 W·mâ 2) and brightness temperature (5-7 W·mâ 2). The generalization of these results to other sensors and study regions could be considered, except for the emissivity if prior knowledge on its characterization is not available.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Remote Sensing of Environment - Volume 175, 15 March 2016, Pages 251-270
Journal: Remote Sensing of Environment - Volume 175, 15 March 2016, Pages 251-270
نویسندگان
Maria Mira, Albert Olioso, Belén Gallego-Elvira, Dominique Courault, Sébastien Garrigues, Olivier Marloie, Olivier Hagolle, Pierre Guillevic, Gilles Boulet,