This study compares the spectral sensitivity of remotely sensed satellite images,used for the detection of archaeological remains.This comparison was based on the relative spectral response(RSR)Filters of each sensor....This study compares the spectral sensitivity of remotely sensed satellite images,used for the detection of archaeological remains.This comparison was based on the relative spectral response(RSR)Filters of each sensor.Spectral signatures profiles were obtained using the GER-1500 field spectroradiometer under clear sky conditions for eight different targets.These field spectral signature curves were simulated to ALOS,ASTER,IKONOS,Landsat 7-ETM-,Landsat 4-TM,Landsat 5-TM and SPOT 5.Red and near infrared(NIR)bandwidth reflectance were re-calculated to each one of these sensors using appropriate RSR Filters.Moreover,the normalised difference vegetation index(NDVI)and simple ratio(SR)vegetation profiles were analysed in order to evaluate their sensitivity to sensors spectral filters.The results have shown that IKONOS RSR filters can better distinguish buried archaeological remains as a result of difference in healthy and stress vegetation(approximately 18%difference in reflectance of the red and NIR band and nearly 0.07 to the NDVI profile).In comparison,all the other sensors showed similar results and sensitivities.This difference of IKONOS sensor might be a result of its spectral characteristics(bandwidths and RSR filters)since they are different from the rest of sensors compared in this study.展开更多
Activities related to agricultural cultivation are some of the major human drivers of landscape change on the Earth＇s surface. Archaeological remains can provide qualitative evidence for studies of past agricultural ...Activities related to agricultural cultivation are some of the major human drivers of landscape change on the Earth＇s surface. Archaeological remains can provide qualitative evidence for studies of past agricultural development and environmental conditions. The ancient Juyan Oasis, which once flourished along the historic Silk Road, was a typical oasis of downstream inland river basins in the arid zone of northwestern China. Historical records and archaeological discoveries have qualitatively shown that the oasis supported extensive agricultural activities in this historical period from the Hart Dynasty to the early Ming Dynasty （B.C. 202-A.D. 1375）, which can be traced back to 2,000 years ago. In this study, different types of archaeological remains （including archaeological sites, ground surface artifacts, ancient cultivation ruins, and agricultural irrigation canals） that were obtained and identified from previous archaeological reports, field inspections, and remote sensing imagery were used to determine the spatial extent of the agricultural oasis in the historical period of interest. Our approach used multiple data sources in order to increase the accuracy and reliability of the results compared to previous studies. Our results distinctly suggested that much of the oasis was cultivated during the historical periods considered. Additionally, the arable land area in the historical period considered was roughly estimated to be approximately （3.39-4.75） × 10^4 ha. These findings regarding the spatial distribution of this ancient agricultural oasis and its arable land were reasonably determined to represent the ancient agricultural development that occurred in the Juyan Oasis better than results obtained from single sources of data.展开更多
文摘This study compares the spectral sensitivity of remotely sensed satellite images,used for the detection of archaeological remains.This comparison was based on the relative spectral response(RSR)Filters of each sensor.Spectral signatures profiles were obtained using the GER-1500 field spectroradiometer under clear sky conditions for eight different targets.These field spectral signature curves were simulated to ALOS,ASTER,IKONOS,Landsat 7-ETM-,Landsat 4-TM,Landsat 5-TM and SPOT 5.Red and near infrared(NIR)bandwidth reflectance were re-calculated to each one of these sensors using appropriate RSR Filters.Moreover,the normalised difference vegetation index(NDVI)and simple ratio(SR)vegetation profiles were analysed in order to evaluate their sensitivity to sensors spectral filters.The results have shown that IKONOS RSR filters can better distinguish buried archaeological remains as a result of difference in healthy and stress vegetation(approximately 18%difference in reflectance of the red and NIR band and nearly 0.07 to the NDVI profile).In comparison,all the other sensors showed similar results and sensitivities.This difference of IKONOS sensor might be a result of its spectral characteristics(bandwidths and RSR filters)since they are different from the rest of sensors compared in this study.
文摘Activities related to agricultural cultivation are some of the major human drivers of landscape change on the Earth＇s surface. Archaeological remains can provide qualitative evidence for studies of past agricultural development and environmental conditions. The ancient Juyan Oasis, which once flourished along the historic Silk Road, was a typical oasis of downstream inland river basins in the arid zone of northwestern China. Historical records and archaeological discoveries have qualitatively shown that the oasis supported extensive agricultural activities in this historical period from the Hart Dynasty to the early Ming Dynasty （B.C. 202-A.D. 1375）, which can be traced back to 2,000 years ago. In this study, different types of archaeological remains （including archaeological sites, ground surface artifacts, ancient cultivation ruins, and agricultural irrigation canals） that were obtained and identified from previous archaeological reports, field inspections, and remote sensing imagery were used to determine the spatial extent of the agricultural oasis in the historical period of interest. Our approach used multiple data sources in order to increase the accuracy and reliability of the results compared to previous studies. Our results distinctly suggested that much of the oasis was cultivated during the historical periods considered. Additionally, the arable land area in the historical period considered was roughly estimated to be approximately （3.39-4.75） × 10^4 ha. These findings regarding the spatial distribution of this ancient agricultural oasis and its arable land were reasonably determined to represent the ancient agricultural development that occurred in the Juyan Oasis better than results obtained from single sources of data.
