A calibration scheme under spherical coordinates is described for a magnetic tracker used in VR (virtual reality) system. A look up table containing data of tracked values for certain positions in the working space, ...A calibration scheme under spherical coordinates is described for a magnetic tracker used in VR (virtual reality) system. A look up table containing data of tracked values for certain positions in the working space, spe cified in spherical coordinates, is generated first, which is then used to calibrate the tracking results by a two dimensional interpolation. The scheme can effectively correct the static errors in the magnetic tracking system. The employment of spherical coordinates significantly reduces the calculation complexity in calibration.展开更多
The precision orbit determination of challenging minisatellite payload(CHAMP) satellite was done based on position and navigation data analyst(PANDA) software which is developed in Wuhan University, using the onboard ...The precision orbit determination of challenging minisatellite payload(CHAMP) satellite was done based on position and navigation data analyst(PANDA) software which is developed in Wuhan University, using the onboard GPS data of year 2002 from day 126 to 131. The orbit accuracy was assessed by analyzing the difference from GFZ post-processed science orbits (PSO), the GPS carrier and pseudo-range data residuals and the satellite laser ranging (SLR) residuals.展开更多
An Unmanned Aircraft System （UAS） is an aircraft or ground station that can be either remote controlled manually or is capable of flying autonomously under the guidance of pre-programmed Global Positioning System （...An Unmanned Aircraft System （UAS） is an aircraft or ground station that can be either remote controlled manually or is capable of flying autonomously under the guidance of pre-programmed Global Positioning System （GPS） waypoint flight plans or more complex onboard intelligent systems. The UAS aircrafts have recently found extensive applications in military reconnaissance and surveillance, homeland security, precision agriculture, fire monitoring and analysis, and other different kinds of aids needed in disasters. Through surveillance videos captured by a UAS digital imaging payload over the interest areas, the corresponding UAS missions can be conducted. In this paper, the authors present an effective method to detect and extract architectural buildings under rural environment from UAS video sequences. The SIFT points are chosen as image features. The planar homography is adopted as the motion model between different image frames. The proposed algorithm is tested on real UAS video data.展开更多
Satellite-to-Satellite Tracking in low-low model （SST-Ⅱ） is a new technique to resolve the series of problems met in the determination of the earth＇s gravity field. As the key technique of SST-Ⅱ, KBR can get SST-...Satellite-to-Satellite Tracking in low-low model （SST-Ⅱ） is a new technique to resolve the series of problems met in the determination of the earth＇s gravity field. As the key technique of SST-Ⅱ, KBR can get SST-Ⅱ measurements directly. So the KBR performance analysis is the first step in SST-Ⅱ design. In this paper, assuming that the satellite pairs of SST-Ⅱ are in near circle polar orbits, the spectrum relationship between the earth gravity field and KBR is established using analytic method. And then some examples are analyzed, the suggestions and conclusions are drawn from these examples. The research results could be taken as a reference for future satellite gravity project of China.展开更多
文摘A calibration scheme under spherical coordinates is described for a magnetic tracker used in VR (virtual reality) system. A look up table containing data of tracked values for certain positions in the working space, spe cified in spherical coordinates, is generated first, which is then used to calibrate the tracking results by a two dimensional interpolation. The scheme can effectively correct the static errors in the magnetic tracking system. The employment of spherical coordinates significantly reduces the calculation complexity in calibration.
文摘The precision orbit determination of challenging minisatellite payload(CHAMP) satellite was done based on position and navigation data analyst(PANDA) software which is developed in Wuhan University, using the onboard GPS data of year 2002 from day 126 to 131. The orbit accuracy was assessed by analyzing the difference from GFZ post-processed science orbits (PSO), the GPS carrier and pseudo-range data residuals and the satellite laser ranging (SLR) residuals.
文摘An Unmanned Aircraft System （UAS） is an aircraft or ground station that can be either remote controlled manually or is capable of flying autonomously under the guidance of pre-programmed Global Positioning System （GPS） waypoint flight plans or more complex onboard intelligent systems. The UAS aircrafts have recently found extensive applications in military reconnaissance and surveillance, homeland security, precision agriculture, fire monitoring and analysis, and other different kinds of aids needed in disasters. Through surveillance videos captured by a UAS digital imaging payload over the interest areas, the corresponding UAS missions can be conducted. In this paper, the authors present an effective method to detect and extract architectural buildings under rural environment from UAS video sequences. The SIFT points are chosen as image features. The planar homography is adopted as the motion model between different image frames. The proposed algorithm is tested on real UAS video data.
基金Project supported by the National Natural Science Foundation of China (No.40374006 , No.40304001) the Foundation for Ph.D project of ChineseMinistry of Education (No.20020486003) .
文摘Satellite-to-Satellite Tracking in low-low model （SST-Ⅱ） is a new technique to resolve the series of problems met in the determination of the earth＇s gravity field. As the key technique of SST-Ⅱ, KBR can get SST-Ⅱ measurements directly. So the KBR performance analysis is the first step in SST-Ⅱ design. In this paper, assuming that the satellite pairs of SST-Ⅱ are in near circle polar orbits, the spectrum relationship between the earth gravity field and KBR is established using analytic method. And then some examples are analyzed, the suggestions and conclusions are drawn from these examples. The research results could be taken as a reference for future satellite gravity project of China.
