This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area rec...This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area reconnaissance of hot regions. First,the working principle and working sequence of the FSM are briefly analyzed. The mathematical model of the FSM system is built by modeling its dynamic and electrical properties, and the rationality of the model is validated by means of model identification. Second,the influence of external sources of disturbance such as the carrier and moment on the control precision of the FSM is effectively suppressed by the jointly controlling of proportional integral(PI)and disturbance observer(DOB), thus realizing a high precision and strong robustness control of the FSM system. Then, this paper designs an experimental prototype and introduces a special optical structure to enable the infrared camera to share the FSM with the visible light camera. Finally, the influence of the velocity difference between the mirror of the FSM and the rotating platform on the imaging quality of the system is experimentally analyzed by using the image sharpness evaluation method based on point sharpness. A good dynamic scanning and staring imaging result is achieved when the velocity of these two components correspond.展开更多
The Staring Area Imaging Technology(SAIT) satellite continuously "images" the target over a certain time range, and can realize continuous imaging and multi-angle imaging of the area of interest. It has the ...The Staring Area Imaging Technology(SAIT) satellite continuously "images" the target over a certain time range, and can realize continuous imaging and multi-angle imaging of the area of interest. It has the characteristics of flexible imaging parameter setting and fast image preprocessing speed, enabling dynamic target detection and tracking, super-resolution, surface 3 D model construction, night-time imaging and many other application tasks. Based on the technical characteristics of the SAIT satellite, this paper analyzes the challenges in satellite development and data processing, focuses on the quasi-realtime application of SAIT satellite data, and looks at the development trend of the SAIT satellite.展开更多
Compared with traditional ground asteroid observations, deep space exploration is an important way to explore and comprehensively understand the characteristics of asteroids. Imaging spectrometer integrates morphologi...Compared with traditional ground asteroid observations, deep space exploration is an important way to explore and comprehensively understand the characteristics of asteroids. Imaging spectrometer integrates morphological measurement and spectral measurement, and has the ability to acquire image and spectral data simultaneously. By combining morphometry and spectrometry, it is possible to achieve efficient identification and quantitative analysis of the chemical components of the exploration target, and has the strong advantage in the field of asteroid exploration. This paper analyzes the principle of the staring imaging spectrometer and the technological progress in various countries. Based on the requirements of light, small payloads and the space characteristics of spectroscopic devices, the application of staring imaging spectrometer is discussed. Then, this paper introduces the conceptual design of an acousto-optic staring imaging spectrometer, combined with the technical characteristics of its area array stare frame imaging and fast electronic control spectrum selection. An experimental verification is carried out, which provides a reference for the feasibility of this type of instrument in asteroid exploration.展开更多
This paper proposes the post-integration technology based on sub-pixel image registration and image fusion to improve the signal-to-noise ratio （SNR） of remote sensing images without motion degradation caused by sat...This paper proposes the post-integration technology based on sub-pixel image registration and image fusion to improve the signal-to-noise ratio （SNR） of remote sensing images without motion degradation caused by satellite vibration. A two-dimensional vibration system is set up to simulate satellite disturbance. Image sequences with different exposure times are captured using a high-speed CMOS camera. The displacement plots are compared with the motion data measured by the grating linear encoder. These plots indicate that the accuracy of the registration algorithm is better than 0.1 pixels. The sub-pixel image fusion shows an improvement in image quality, thus indicating that this technology is powerful for staring imaging systems in geostationary orbit.展开更多
An infrared （IR） imaging simulation framework based on the strap-down platform is proposed for midcourse ballistic targets. It overcomes the shortcoming of the existing algorithms, which cannot simulate IR imaging f...An infrared （IR） imaging simulation framework based on the strap-down platform is proposed for midcourse ballistic targets. It overcomes the shortcoming of the existing algorithms, which cannot simulate IR imaging from the entire midcourse process. The proposed framework includes three steps, target characteristic modeling, motion modeling, and imaging modeling. In imaging modeling, the staring focal plane is taken into account due to its wide employment. In order to obtain IR images of high fidelity, especially that the fluctuation of the target signal-to-noise ratio （SNR） is reasonably similar to the actual one, this paper proposes an improved IR imaging simulation method. The proposed method considers two critical factors of the pixel plane, occupy-empty ratio and defect elements, which affect the imaging of targets markedly but are neglected in previous work. Finally, the IR image sequence of high fidelity is obtained. And the correlative parameters of simulation can be set according to the given scene. Thus the generated images can satisfy the needs of algorithms validation for tracking and recognition.展开更多
Imagine a child who does not want to eat dumplings,despite being told by his grandfather to do so.Confused,the child picks up the bowl and stares at it for over an hour,not eating but also refusing to put it down.“Th...Imagine a child who does not want to eat dumplings,despite being told by his grandfather to do so.Confused,the child picks up the bowl and stares at it for over an hour,not eating but also refusing to put it down.“That is what has happened one day in Urumqi Love Garden(ULG)[in Xinjiang],Lyu Xiaoning,the founder of Viva la Vida(VIVA),a global platform for people to share stories through art,told Beijing Review.VIVAowns anonlineart gallery and social networking platform to exhibit portraits of life by different people.”展开更多
Beijing-based artistic voyeur Song Yonghong thrives on the complexities of life in everyday settings.Although there’s a lot of sexual intimacy in his work,the participants give off a sense of detachment—the intense ...Beijing-based artistic voyeur Song Yonghong thrives on the complexities of life in everyday settings.Although there’s a lot of sexual intimacy in his work,the participants give off a sense of detachment—the intense stares of American Gothic meeting the lonely streets of Edward Hopper.展开更多
Heads or Tails A boy was taking the final examination which consisted of“Yes”or“No”questions.He took a seat in the classroom stared at the test paper for five minutes,and then had an idea.He started tossing the co...Heads or Tails A boy was taking the final examination which consisted of“Yes”or“No”questions.He took a seat in the classroom stared at the test paper for five minutes,and then had an idea.He started tossing the coin(抛硬币)and marking the answer sheet“Yes”for Heads and“No”for Tails.展开更多
基金supported by the National Defense Pre-research Project of China during the 12th Five-year Plan Period(4040570201)Innovation Project of Military Academy(ZYX14060014)
文摘This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area reconnaissance of hot regions. First,the working principle and working sequence of the FSM are briefly analyzed. The mathematical model of the FSM system is built by modeling its dynamic and electrical properties, and the rationality of the model is validated by means of model identification. Second,the influence of external sources of disturbance such as the carrier and moment on the control precision of the FSM is effectively suppressed by the jointly controlling of proportional integral(PI)and disturbance observer(DOB), thus realizing a high precision and strong robustness control of the FSM system. Then, this paper designs an experimental prototype and introduces a special optical structure to enable the infrared camera to share the FSM with the visible light camera. Finally, the influence of the velocity difference between the mirror of the FSM and the rotating platform on the imaging quality of the system is experimentally analyzed by using the image sharpness evaluation method based on point sharpness. A good dynamic scanning and staring imaging result is achieved when the velocity of these two components correspond.
文摘The Staring Area Imaging Technology(SAIT) satellite continuously "images" the target over a certain time range, and can realize continuous imaging and multi-angle imaging of the area of interest. It has the characteristics of flexible imaging parameter setting and fast image preprocessing speed, enabling dynamic target detection and tracking, super-resolution, surface 3 D model construction, night-time imaging and many other application tasks. Based on the technical characteristics of the SAIT satellite, this paper analyzes the challenges in satellite development and data processing, focuses on the quasi-realtime application of SAIT satellite data, and looks at the development trend of the SAIT satellite.
文摘Compared with traditional ground asteroid observations, deep space exploration is an important way to explore and comprehensively understand the characteristics of asteroids. Imaging spectrometer integrates morphological measurement and spectral measurement, and has the ability to acquire image and spectral data simultaneously. By combining morphometry and spectrometry, it is possible to achieve efficient identification and quantitative analysis of the chemical components of the exploration target, and has the strong advantage in the field of asteroid exploration. This paper analyzes the principle of the staring imaging spectrometer and the technological progress in various countries. Based on the requirements of light, small payloads and the space characteristics of spectroscopic devices, the application of staring imaging spectrometer is discussed. Then, this paper introduces the conceptual design of an acousto-optic staring imaging spectrometer, combined with the technical characteristics of its area array stare frame imaging and fast electronic control spectrum selection. An experimental verification is carried out, which provides a reference for the feasibility of this type of instrument in asteroid exploration.
基金supported by the National Natural Science Foundation of China(No.61036015)
文摘This paper proposes the post-integration technology based on sub-pixel image registration and image fusion to improve the signal-to-noise ratio （SNR） of remote sensing images without motion degradation caused by satellite vibration. A two-dimensional vibration system is set up to simulate satellite disturbance. Image sequences with different exposure times are captured using a high-speed CMOS camera. The displacement plots are compared with the motion data measured by the grating linear encoder. These plots indicate that the accuracy of the registration algorithm is better than 0.1 pixels. The sub-pixel image fusion shows an improvement in image quality, thus indicating that this technology is powerful for staring imaging systems in geostationary orbit.
文摘An infrared （IR） imaging simulation framework based on the strap-down platform is proposed for midcourse ballistic targets. It overcomes the shortcoming of the existing algorithms, which cannot simulate IR imaging from the entire midcourse process. The proposed framework includes three steps, target characteristic modeling, motion modeling, and imaging modeling. In imaging modeling, the staring focal plane is taken into account due to its wide employment. In order to obtain IR images of high fidelity, especially that the fluctuation of the target signal-to-noise ratio （SNR） is reasonably similar to the actual one, this paper proposes an improved IR imaging simulation method. The proposed method considers two critical factors of the pixel plane, occupy-empty ratio and defect elements, which affect the imaging of targets markedly but are neglected in previous work. Finally, the IR image sequence of high fidelity is obtained. And the correlative parameters of simulation can be set according to the given scene. Thus the generated images can satisfy the needs of algorithms validation for tracking and recognition.
文摘Imagine a child who does not want to eat dumplings,despite being told by his grandfather to do so.Confused,the child picks up the bowl and stares at it for over an hour,not eating but also refusing to put it down.“That is what has happened one day in Urumqi Love Garden(ULG)[in Xinjiang],Lyu Xiaoning,the founder of Viva la Vida(VIVA),a global platform for people to share stories through art,told Beijing Review.VIVAowns anonlineart gallery and social networking platform to exhibit portraits of life by different people.”
文摘Beijing-based artistic voyeur Song Yonghong thrives on the complexities of life in everyday settings.Although there’s a lot of sexual intimacy in his work,the participants give off a sense of detachment—the intense stares of American Gothic meeting the lonely streets of Edward Hopper.
文摘Heads or Tails A boy was taking the final examination which consisted of“Yes”or“No”questions.He took a seat in the classroom stared at the test paper for five minutes,and then had an idea.He started tossing the coin(抛硬币)and marking the answer sheet“Yes”for Heads and“No”for Tails.
