The traditional approach of star tracker for determining the centroid of spot requires enough energy and good shape, so a relatively long exposure time and stable three-axis state become necessary conditions to maintain high accuracy, these limit its update rate and dynamic performance. In view of these issues, this paper presents an approach for determining the centroid of star spot which base...

In a detector system, clock distribution to sensors must be controlled at a level allowing proper synchronisation. In order to reach theses requirements for the HFT (Heavy Flavor Tracker) upgrade at STAR (Solenoidal Tracker at RHIC), we have proposed to distribute a low frequency clock at 10 MHz which will be multiplied to 160 MHz in each sensor by a PLL. A PLL has been designed for period jitt...

Abstract A star tracker calibration method using images is presented in this paper. Unlike previous works, the proposed estimates all parameters and attitudes at once a single least-squares formulation for optimal calibration, which can be easily converted to recursive estimation form. In addition, paper presents estimate overall performance attitude determination from results. Since uses only,...

NAVSYS Corporation and Microcosm, Inc., have jointly developed a design for a flexible, high-performance, miniaturized, space-based Software GPS Receiver (SSGR) based on a Software Defined Radio (SDR) architecture that optimally combines GPS, INS, and star-tracker inputs to provide a flexible, integrated precision navigation and attitude determination solution for space applications. The SSGR i...

Attitude data, which is the important data strongly correlated with the geometric accuracy of optical remote sensing satellite images, are generally obtained using a real-time Extended Kalman Filter (EKF) with star-tracker and gyro data for current high-resolution satellites, such as Orb-view, IKONOS, Quickbird,Pleiades, and ZY-3.We propose a forwardbackward Unscented Kalman Filter (UKF) for po...