The geometric accuracy of topographic mapping with high-resolution remote sensing images is inevita-bly affected by the orbiter attitude jitter.Therefore,it is necessary to conduct preliminary research on the stereo m...The geometric accuracy of topographic mapping with high-resolution remote sensing images is inevita-bly affected by the orbiter attitude jitter.Therefore,it is necessary to conduct preliminary research on the stereo mapping camera equipped on lunar orbiter before launching.In this work,an imaging simulation method consid-ering the attitude jitter is presented.The impact analysis of different attitude jitter on terrain undulation is conduct-ed by simulating jitter at three attitude angles,respectively.The proposed simulation method is based on the rigor-ous sensor model,using the lunar digital elevation model(DEM)and orthoimage as reference data.The orbit and attitude of the lunar stereo mapping camera are simulated while considering the attitude jitter.Two-dimensional simulated stereo images are generated according to the position and attitude of the orbiter in a given orbit.Experi-mental analyses were conducted by the DEM with the simulated stereo image.The simulation imaging results demonstrate that the proposed method can ensure imaging efficiency without losing the accuracy of topographic mapping.The effect of attitude jitter on the stereo mapping accuracy of the simulated images was analyzed through a DEM comparison.展开更多
While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capt...While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capturing a picture of a some which has both brightly and poorly illuminated regions. High Dynamic Range （HDR） imaging aims to recover the entire dynamic range of the scene by compositing multi-exposure images. Tone reproduction is required for displaying HDR images as the corresponding Low Dynamic Range（LDR） images on common displays. This paper discusses novel approaches to reconstruct LDR images directly from multi-exposure images. It is assumed that there is no knowledge of camera response function and other camera settings. At last, it is explained how this task can be achieved effectively for static and dynamic scenes.展开更多
For ballistic mid-course targets,in addition to constant orbital motion,the target or any structure on the target undergoes micro-motion dynamics,such as spin,precession and tumbling.The micro-motion characteristics o...For ballistic mid-course targets,in addition to constant orbital motion,the target or any structure on the target undergoes micro-motion dynamics,such as spin,precession and tumbling.The micro-motion characteristics of the ballistic mid-course targets were discussed.The target motion model and inverse synthetic aperture radar(ISAR) imaging model for this kind of targets were built.Then,the influence of micro-motion on ISAR imaging based on the established imaging model was presented.The computer simulation to get mid-course target echoes from static darkroom electromagnetic scattering data based on the established target motion model was realized.The imaging results of computer simulation show the validity of ISAR imaging analysis for micro-motion targets.展开更多
The use of computed microtomography （p.CT） has revolutionized many areas of research, such as noninvasive, fast and high precision techniques, which allows immediate visualization of internal structures without any ...The use of computed microtomography （p.CT） has revolutionized many areas of research, such as noninvasive, fast and high precision techniques, which allows immediate visualization of internal structures without any risk to the object of study. ~tCT is widely accepted for medical diagnostics, is also important for purposes of zoological research and paleontological. In this work, we used the μCT to investigate the internal structure of bones from mammalian and poultry. We studied the bones of rats and quail. Through microtomography images, we observed that the bones of the poultry have a bony structure in the form of a trellis that is not present in bones of mammals. These trellises bony is an evolutionary adaptation that allowed the bones of the birds to become longer and lighter maintaining its strength. It was also observed that the percentage of the trabecular area in poultry is almost half of that observed in mammals. The results obtained validate the use of μCT as a technique that allows the study of bone structures in small samples, enabling to explore the morphological differences between the bones of those species.展开更多
Applying the theory of adaptation, Feminism, and Performance Studies, this paper explores the adaptation, inter-textuality, and gender in the three films The Tempest （2010） directed by Julie Taymor, Prospero＇s Boo...Applying the theory of adaptation, Feminism, and Performance Studies, this paper explores the adaptation, inter-textuality, and gender in the three films The Tempest （2010） directed by Julie Taymor, Prospero＇s Books （1991） directed by Peter Greenaway, and Shakespeare in Love （1998） directed by John Madden, referenced to Gnomeo and Juliet （2011）, a cartoon animation. Both films of The Tempest show visual spectacle and technology images by CGI （Computer-Generated Cinematic Graphic Image） effect. The author argues the power struggle between Caliban and Prospero played by actress Helen Mirren, changes from post-colonial discourse in the male domain, to be more about the intellect contest between man and woman, and Taymor＇s adaptation is more focused on maternity than actor John Gielgud＇s on politics. Inter-textuality exists in Shakespeare in Love and Shakespeare＇s Romeo and Juliet, and Twelfth Night. Unlike the tragedy in the films, Gnomeo and Juliet ends happily as we can expect from most musicals and fairy tales. The inter-textuality of literature and art, dramatic plays, historical events, and biographical sketches are delicately intertwined. Media represent Shakespeare applied by Jean Baudrillard＇s ＂simulacra＂ and Richard Schechner＇s ＂simulation＂ to present the liminal threshold between reality, role-playing, and theatricality. Shakespeare represented by media rise to visual narratives.展开更多
To accomplish high-resolution imaging of the preselected landing area, it was necessary for the Chang＇E-2 mission to perform orbital maneuvering on the far side of the moon to meet the conditional height requirement ...To accomplish high-resolution imaging of the preselected landing area, it was necessary for the Chang＇E-2 mission to perform orbital maneuvering on the far side of the moon to meet the conditional height requirement of the imaging area. Engine shutdown would be executed invisibly on the back side of the moon if the descent maneuver mode opposite to the target perilune or the fuel optimal maneuver mode was used. To ensure the satellite safety, the project collectivety required that the engine shutdown should be designed to be executed in the domestic segmental arcs and meet the requirement of satellite emergency treatment simultaneously. Accordingly, the asymmetric-descent orbit control technology was adopted by offsetting the ma- neuver point, which obtained the orbit control parameters of finite-thrust mode with an iteration algorithm and modified the results with target perilune drift estimation. The Chang＇E-2 satellite declined to the target of 100 km×l5 km orbit successfully on 26 October 2010, and has been flying for 32 circles in the experimental orbit to accomplish the preselected landing area imaging. This paper describes the mechanism and realization method of the asymmetric-descent orbit control technology and evaluates the maneuver effect with the actual mission data.展开更多
基金Supported by the National Natural Science Foundation of China(42221002,42171432)Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)the Fundamental Research Funds for the Central Universities.
文摘The geometric accuracy of topographic mapping with high-resolution remote sensing images is inevita-bly affected by the orbiter attitude jitter.Therefore,it is necessary to conduct preliminary research on the stereo mapping camera equipped on lunar orbiter before launching.In this work,an imaging simulation method consid-ering the attitude jitter is presented.The impact analysis of different attitude jitter on terrain undulation is conduct-ed by simulating jitter at three attitude angles,respectively.The proposed simulation method is based on the rigor-ous sensor model,using the lunar digital elevation model(DEM)and orthoimage as reference data.The orbit and attitude of the lunar stereo mapping camera are simulated while considering the attitude jitter.Two-dimensional simulated stereo images are generated according to the position and attitude of the orbiter in a given orbit.Experi-mental analyses were conducted by the DEM with the simulated stereo image.The simulation imaging results demonstrate that the proposed method can ensure imaging efficiency without losing the accuracy of topographic mapping.The effect of attitude jitter on the stereo mapping accuracy of the simulated images was analyzed through a DEM comparison.
文摘While capturing a real world scene using a common digital camera, due to limitations of the sensor dynamic range, we will not be able to capture the entire dynamic range of the some. This problem is evident while capturing a picture of a some which has both brightly and poorly illuminated regions. High Dynamic Range （HDR） imaging aims to recover the entire dynamic range of the scene by compositing multi-exposure images. Tone reproduction is required for displaying HDR images as the corresponding Low Dynamic Range（LDR） images on common displays. This paper discusses novel approaches to reconstruct LDR images directly from multi-exposure images. It is assumed that there is no knowledge of camera response function and other camera settings. At last, it is explained how this task can be achieved effectively for static and dynamic scenes.
基金Project(61360020102) supported by the National Basic Research Development Program of China
文摘For ballistic mid-course targets,in addition to constant orbital motion,the target or any structure on the target undergoes micro-motion dynamics,such as spin,precession and tumbling.The micro-motion characteristics of the ballistic mid-course targets were discussed.The target motion model and inverse synthetic aperture radar(ISAR) imaging model for this kind of targets were built.Then,the influence of micro-motion on ISAR imaging based on the established imaging model was presented.The computer simulation to get mid-course target echoes from static darkroom electromagnetic scattering data based on the established target motion model was realized.The imaging results of computer simulation show the validity of ISAR imaging analysis for micro-motion targets.
文摘The use of computed microtomography （p.CT） has revolutionized many areas of research, such as noninvasive, fast and high precision techniques, which allows immediate visualization of internal structures without any risk to the object of study. ~tCT is widely accepted for medical diagnostics, is also important for purposes of zoological research and paleontological. In this work, we used the μCT to investigate the internal structure of bones from mammalian and poultry. We studied the bones of rats and quail. Through microtomography images, we observed that the bones of the poultry have a bony structure in the form of a trellis that is not present in bones of mammals. These trellises bony is an evolutionary adaptation that allowed the bones of the birds to become longer and lighter maintaining its strength. It was also observed that the percentage of the trabecular area in poultry is almost half of that observed in mammals. The results obtained validate the use of μCT as a technique that allows the study of bone structures in small samples, enabling to explore the morphological differences between the bones of those species.
文摘Applying the theory of adaptation, Feminism, and Performance Studies, this paper explores the adaptation, inter-textuality, and gender in the three films The Tempest （2010） directed by Julie Taymor, Prospero＇s Books （1991） directed by Peter Greenaway, and Shakespeare in Love （1998） directed by John Madden, referenced to Gnomeo and Juliet （2011）, a cartoon animation. Both films of The Tempest show visual spectacle and technology images by CGI （Computer-Generated Cinematic Graphic Image） effect. The author argues the power struggle between Caliban and Prospero played by actress Helen Mirren, changes from post-colonial discourse in the male domain, to be more about the intellect contest between man and woman, and Taymor＇s adaptation is more focused on maternity than actor John Gielgud＇s on politics. Inter-textuality exists in Shakespeare in Love and Shakespeare＇s Romeo and Juliet, and Twelfth Night. Unlike the tragedy in the films, Gnomeo and Juliet ends happily as we can expect from most musicals and fairy tales. The inter-textuality of literature and art, dramatic plays, historical events, and biographical sketches are delicately intertwined. Media represent Shakespeare applied by Jean Baudrillard＇s ＂simulacra＂ and Richard Schechner＇s ＂simulation＂ to present the liminal threshold between reality, role-playing, and theatricality. Shakespeare represented by media rise to visual narratives.
文摘To accomplish high-resolution imaging of the preselected landing area, it was necessary for the Chang＇E-2 mission to perform orbital maneuvering on the far side of the moon to meet the conditional height requirement of the imaging area. Engine shutdown would be executed invisibly on the back side of the moon if the descent maneuver mode opposite to the target perilune or the fuel optimal maneuver mode was used. To ensure the satellite safety, the project collectivety required that the engine shutdown should be designed to be executed in the domestic segmental arcs and meet the requirement of satellite emergency treatment simultaneously. Accordingly, the asymmetric-descent orbit control technology was adopted by offsetting the ma- neuver point, which obtained the orbit control parameters of finite-thrust mode with an iteration algorithm and modified the results with target perilune drift estimation. The Chang＇E-2 satellite declined to the target of 100 km×l5 km orbit successfully on 26 October 2010, and has been flying for 32 circles in the experimental orbit to accomplish the preselected landing area imaging. This paper describes the mechanism and realization method of the asymmetric-descent orbit control technology and evaluates the maneuver effect with the actual mission data.
