Attitude Control Systems for Imaging the Moonlit Ground: Development and On-Orbit Updating Results of CE-SAT-IIB

Canon Electronics Inc. (CEI) is developing optical micro satellites “CE-SAT” for demonstrating in-house attitude determination and control systems (ADCS) and optical systems in order to achieve high-resolution and high-sensitivity imaging. CEI is now operating two satellites on orbit. The second satellite CE-SAT-IIB has the ability to take images of the ground surface with 5m GSD in the night using an Ultra High Sensitivity Camera (UHSC) and a highly accurate ADCS. The satellite has ability to track the ground with 20 arcsec/s or better of pointing stability, and this makes 100 milliseconds or longer exposure time possible. As the result, the satellite can get images of the moonlit ground surface clearly. To realize such high stability of pointing, CEI developed most components for ADCS in-house and updated software of the satellite and components on orbit. Now CE-SAT-IIB can get the ground images with 1800 milliseconds exposure time and get color images of night deserts like imaging in daylight. Additionally, this ADCS enables the satellite to get various images of the ground with changing area, sensitivity, and temporal resolution of imaging by selecting a target of pointing, exposure time, and imaging interval. Furthermore, high-speed moving objects including satellites and space debris can be photographed utilizing the high sensitivity of the UHSC

Detecting and Tracking Vulnerable Road Users\u27 Trajectories Using Different Types of Sensors Fusion

Vulnerable road user (VRU) detection and tracking has been a key challenge in transportation research. Different types of sensors such as the camera, LiDAR, and inertial measurement units (IMUs) have been used for this purpose. For detection and tracking with the camera, it is necessary to perform calibration to obtain correct GPS trajectories. This method is often tedious and necessitates accurate ground truth data. Moreover, if the camera performs any pan-tilt-zoom function, it is usually necessary to recalibrate the camera. In this thesis, we propose camera calibration using an auxiliary sensor: ultra-wideband (UWB). USBs are capable of tracking a road user with ten-centimeter-level accuracy. Once a VRU with a UWB traverses in the camera view, the UWB GPS data is fused with the camera to perform real-time calibration. As the experimental results in this thesis have shown, the camera is able to output better trajectories after calibration. It is expected that the use of UWB is needed only once to fuse the data and determine the correct trajectories at the same intersection and location of the camera. All other trajectories collected by the camera can be corrected using the same adjustment. In addition, data analysis was conducted to evaluate the performance of the UWB sensors. This study also predicted pedestrian trajectories using data fused by the UWB and smartphone sensors. UWB GPS coordinates are very accurate although it lacks other sensor parameters such as accelerometer, gyroscope, etc. The smartphone data have been used in this scenario to augment the UWB data. The two datasets were merged on the basis of the closest timestamp. The resulting dataset has precise latitude and longitude from UWB as well as the accelerometer, gyroscope, and speed data from smartphones making the fused dataset accurate and rich in terms of parameters. The fused dataset was then used to predict the GPS coordinates of pedestrians and scooters using LSTM

High Sensitive Night-time Light Imaging Camera Design and In-orbit Test of Luojia1-01 Satellite

Luojia1-01 satellite is the first scientific experimental satellite applied for night-time light remote sensing data acquisition, and the payload is an optical camera with high sensitivity, high radiation measurement accuracy and stable elements of interior orientation. At the same time, a special shaped hood is designed, which significantly improved the ability of the camera to suppress stray light. Camera electronics adopts the integrated design of focal plane and imaging processing, which greatly reduces the volume and weight of the system. In this paper, the design of the optical camera is summarized, and the results of in-orbit imaging performance tests are analyzed. The results show that the dynamic modulation transfer function (MTF) of the camera is better than 0.17, and the SNR is better than 35 dB under the condition of 10 lx illuminance and 0.3 reflectivity and all indicators meet the design requirements. The data obtained have been widely applied in many fields such as the process of urbanization, light pollution analysis, marine fisheries detection and military