Airborne 3D image which integrates GPS, attitude measurement unit (AMU), scanning laser rangefinder (SLR) and spectra scanner has been developed successfully. The spectral scanner and SLR use the same optical system w...Airborne 3D image which integrates GPS, attitude measurement unit (AMU), scanning laser rangefinder (SLR) and spectra scanner has been developed successfully. The spectral scanner and SLR use the same optical system which ensures laser point to match pixel seamlessly. The distinctive advantage of 3D image is that it can produce geo-referenced images and DSM (digital surface models) images without any ground control points (GCPs). It is no longer necessary to survey GCPs and with some softwares the data can be processed and produce digital surface models (DSM) and geo-referenced images in quasi-real-time, therefore the efficiency of 3D image is 10–100 times higher than that of traditional approaches. The processing procedure involves decomposing and checking the raw data, processing GPS data, calculating the positions of laser sample points, producing geo-referenced image, producing DSM and mosaicing strips. The principle of 3D image is first introduced in this paper, and then we focus on the fast processing technique and algorithms. The flight tests and processed results show that the processing technique is feasible and can meet the requirement of quasi-real-time applications.展开更多
The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM laye...The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM layer,the fiber shape and operation frequencies.The results indicate that the shape of dielectric fiber affects the hybrid mode significantly,on the condition that if ax(the semi-minor axis length of the dielectric semi-ellipse)is relatively small,the fiber shows good mode confinement and low loss simultaneously,and the figure of merit reaches more than 200.The propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM,e.g.if the Fermi level varies in the range of 0.05 eV–0.15 eV,the propagation length changes in the range of 9.073×10^(3)–2.715×10^(4)μm,and the corresponding modulation depth is 66.5%.These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices,such as switchers,modulators,and sensors.展开更多
The Arun and Tista Rivers,which flow across the Himalayas,are commonly known as antecedent valleys that overcame the rapid uplift of the Higher Himalayan ranges.To clarify whether the idea of antecedent rivers is acce...The Arun and Tista Rivers,which flow across the Himalayas,are commonly known as antecedent valleys that overcame the rapid uplift of the Higher Himalayan ranges.To clarify whether the idea of antecedent rivers is acceptable,we investigated the geomorphology of the Himalayas between eastern Nepal and Bhutan Himalayas.The southern part of Tibetan Plateau,extending across the Himalayas as tectonically un-deformed glaciated terrain named as'Tibetan Corridor,'does not suggest the regional uplift of the Higher Himalayas.The 8,000-m class mountains of Everest,Makalu,and Kanchenjunga are isolated residual peaks on the glaciated terrain composed of mountain peaks of 4,000–6,000 m high.The Tibetan glaciers commonly beheaded by Himalayan glaciers along the great watershed of the Himalayas suggest the expansion of Himalayan river drainage by glaciation.For the narrow upstream regions of the Arun and Tista Rivers with less precipitation behind the range,it is hard to collect enough water for the power of down-cutting their channels against the uplifting Himalayas.The fission track ages of the Higher Himalayan Crystalline Nappe suggest that the Himalayas attained their present altitude by 11–10 Ma,and the Arun and Tista Rivers formed deep gorges across the Himalayas by headward erosion.展开更多
A 3D forest monitoring system,called FORSAT(a satellite very high resolution image processing platform for forest assessment),was developed for the extraction of 3D geometric forest information from very high resoluti...A 3D forest monitoring system,called FORSAT(a satellite very high resolution image processing platform for forest assessment),was developed for the extraction of 3D geometric forest information from very high resolution(VHR)satellite imagery and the automatic 3D change detection.FORSAT is composed of two complementary tasks:(1)the geometric and radiometric processing of satellite optical imagery and digital surface model(DSM)reconstruction by using a precise and robust image matching approach specially designed for VHR satellite imagery,(2)3D surface comparison for change detection.It allows the users to import DSMs,align them using an advanced 3D surface matching approach and calculate the 3D differences and volume changes(together with precision values)between epochs.FORSAT is a single source and flexible forest information solution,allowing expert and non-expert remote sensing users to monitor forests in three and four(time)dimensions.The geometric resolution and thematic content of VHR optical imagery are sufficient for many forest information needs such as deforestation,clear-cut and fire severity mapping.The capacity and benefits of FORSAT,as a forest information system contributing to the sustainable forest management,have been tested and validated in case studies located in Austria,Switzerland and Spain.展开更多
In this study,we have investigated the mathematical components of the Dirac equation in curved spacetime and how they can be applied to the analysis of neutrino oscillations.More specifically,we have developed a metho...In this study,we have investigated the mathematical components of the Dirac equation in curved spacetime and how they can be applied to the analysis of neutrino oscillations.More specifically,we have developed a method for calculating the phase shift in flavor neutrino oscillations by utilizing a Taylor series expansion of the action that takes into account△m^(4) orders.In addition,we have used this method to assess how the phase difference in neutrino mass eigenstates changes according to the gravitational field described by the Johannsen spacetime.展开更多
文摘Airborne 3D image which integrates GPS, attitude measurement unit (AMU), scanning laser rangefinder (SLR) and spectra scanner has been developed successfully. The spectral scanner and SLR use the same optical system which ensures laser point to match pixel seamlessly. The distinctive advantage of 3D image is that it can produce geo-referenced images and DSM (digital surface models) images without any ground control points (GCPs). It is no longer necessary to survey GCPs and with some softwares the data can be processed and produce digital surface models (DSM) and geo-referenced images in quasi-real-time, therefore the efficiency of 3D image is 10–100 times higher than that of traditional approaches. The processing procedure involves decomposing and checking the raw data, processing GPS data, calculating the positions of laser sample points, producing geo-referenced image, producing DSM and mosaicing strips. The principle of 3D image is first introduced in this paper, and then we focus on the fast processing technique and algorithms. The flight tests and processed results show that the processing technique is feasible and can meet the requirement of quasi-real-time applications.
基金the Natural Science Foundation of Shanghai under Grant Nos.21ZR1446500Shanghai Local College Capacity Building Project under Grant No.22010503300 and 21010503200+4 种基金the Research Funding of Shanghai Normal University under Grant No.SK202240National Natural Science Foundation of China under Grant Nos.61674106,12073018,U1931205the Funding of Shanghai Municipal Education Commission under Grant No 2019-01-07-00-02-E00032the Funding of Shanghai Municipality Science and Technology Commission under Grant No 19590746000,20070502400,YDZX20203100002498Student Research Project of Shanghai Normal University(undergraduate)under Grant No.22LKY022.
文摘The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM layer,the fiber shape and operation frequencies.The results indicate that the shape of dielectric fiber affects the hybrid mode significantly,on the condition that if ax(the semi-minor axis length of the dielectric semi-ellipse)is relatively small,the fiber shows good mode confinement and low loss simultaneously,and the figure of merit reaches more than 200.The propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM,e.g.if the Fermi level varies in the range of 0.05 eV–0.15 eV,the propagation length changes in the range of 9.073×10^(3)–2.715×10^(4)μm,and the corresponding modulation depth is 66.5%.These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices,such as switchers,modulators,and sensors.
基金This work was supported by Grants-in-Aid for Scientific Research of the Japanese Society for the Promotion of Science(JSPS KAKENHI)Grant Number 18H00766(principal investigator:Takashi Nakata)Grant Number 18KK0027(principal investigator:Yasuhiro Kumahara).
文摘The Arun and Tista Rivers,which flow across the Himalayas,are commonly known as antecedent valleys that overcame the rapid uplift of the Higher Himalayan ranges.To clarify whether the idea of antecedent rivers is acceptable,we investigated the geomorphology of the Himalayas between eastern Nepal and Bhutan Himalayas.The southern part of Tibetan Plateau,extending across the Himalayas as tectonically un-deformed glaciated terrain named as'Tibetan Corridor,'does not suggest the regional uplift of the Higher Himalayas.The 8,000-m class mountains of Everest,Makalu,and Kanchenjunga are isolated residual peaks on the glaciated terrain composed of mountain peaks of 4,000–6,000 m high.The Tibetan glaciers commonly beheaded by Himalayan glaciers along the great watershed of the Himalayas suggest the expansion of Himalayan river drainage by glaciation.For the narrow upstream regions of the Arun and Tista Rivers with less precipitation behind the range,it is hard to collect enough water for the power of down-cutting their channels against the uplifting Himalayas.The fission track ages of the Higher Himalayan Crystalline Nappe suggest that the Himalayas attained their present altitude by 11–10 Ma,and the Arun and Tista Rivers formed deep gorges across the Himalayas by headward erosion.
基金the EUROSTARS[grant number E!7358]funding scheme,co-funded by the European Commission and the participating countries.
文摘A 3D forest monitoring system,called FORSAT(a satellite very high resolution image processing platform for forest assessment),was developed for the extraction of 3D geometric forest information from very high resolution(VHR)satellite imagery and the automatic 3D change detection.FORSAT is composed of two complementary tasks:(1)the geometric and radiometric processing of satellite optical imagery and digital surface model(DSM)reconstruction by using a precise and robust image matching approach specially designed for VHR satellite imagery,(2)3D surface comparison for change detection.It allows the users to import DSMs,align them using an advanced 3D surface matching approach and calculate the 3D differences and volume changes(together with precision values)between epochs.FORSAT is a single source and flexible forest information solution,allowing expert and non-expert remote sensing users to monitor forests in three and four(time)dimensions.The geometric resolution and thematic content of VHR optical imagery are sufficient for many forest information needs such as deforestation,clear-cut and fire severity mapping.The capacity and benefits of FORSAT,as a forest information system contributing to the sustainable forest management,have been tested and validated in case studies located in Austria,Switzerland and Spain.
基金Supported by the Grants F-FA-2021-510 from the Uzbekistan Ministry for Innovative Development。
文摘In this study,we have investigated the mathematical components of the Dirac equation in curved spacetime and how they can be applied to the analysis of neutrino oscillations.More specifically,we have developed a method for calculating the phase shift in flavor neutrino oscillations by utilizing a Taylor series expansion of the action that takes into account△m^(4) orders.In addition,we have used this method to assess how the phase difference in neutrino mass eigenstates changes according to the gravitational field described by the Johannsen spacetime.
