Thai Space Consortium (TSC) was originally a cooperation program by 13 leading Thailand research organizations that proposed to develop a microsatellite for a scientific mission; moreover, the aim of the TSC program includes sharing and enhancing an advanced engineering capacity in Thailand. Due to the National Astronomical Research Institute of Thailand (NARIT) being a part of the TSC contributor; therefore, the development of the star tracker is first promoted to be an astronomical-driven project through the eye of astronomical engineers. In practice, the knowledge of star trackers can apply to satellite attitude determination systems. It is the most precisely measured absolute three-axis orientation of a spacecraft when integrated with relative sensors. Therefore, in this work, the potential of using an 0.7-meter optical telescope-based for software experimentation as a function of stars pattern recognition and attitude determination algorithms according to the detected stars on astronomical images. The image is mapped to the guide star catalog to correct the magnification, shear, and rotation of the image sensor respective to the Cartesian coordinates as a function of astrometry engineering. The result of the method is a plate-constant that then corrects the positions of a target celestial body. An inertial measurement unit (IMU) was equipped with the telescope mounting to collect the local orientation of the telescope itself to demonstrate the results of attitude determination in both deterministic-TRIAD method and solving loss function based on Wahba’s problem. The proposed system integration method can be performed with negligible attitude determination error compared to the IMU-baseline attitude sensor. This contribution will present some of the experimental results and plans for further measurement campaigns.
Increasing demand of satellites usage, our community raises awareness of space debris, which could collide with our space inventions. To avoid an unnecessary cost, many engineers resolve this issue with a ground-based observation, which is one of the inexpensive ways of tracked celestial bodies in the Earth vicinity. To use a plain optical telescope without laser ranging to determine orbital parameters by using angles only through Gauss method, and with appropriate calibrating a telescope mounting on a ground station. In this paper, we propose three main parts by first, presenting a concept of calibrating technique on how to obtain observation angle pair when an object is not at the center of image sensor. Second, we optimize the Gauss method’s execution time. Third, we validate that our generated Two-Line Element can be used to track celestial bodies. In our experiment, an 0.7-meter optical telescope equips with image sensor which is located at National Astronomical Research Institute of Thailand, Chiang-Mai, Thailand to project stars on image sensor. The image is mapped to stars database to correct the magnification, shear, and rotation of the image sensor respective to the Cartesian coordinates as a function of astrometry engineering. The result of the method is a plate constant. It is used to correct positions of an interesting celestial body tracked. In this second main part, we investigate the execution time with the same accuracy to other solver of the Gauss method in the famous eight order polynomial. The proposed solver is Laguerre method to find a root finding with convergence rate of cubic. Finally, Our result is proved to be reliable to use as a Two-Line Element update in our telescope system.
The preferred programming languages and operating systems used in writing and running astrometric software have changed over time. The Python language is now well supported by the scientific community which provides open-source standard libraries for astronomical calculation including Astropy,1 SciPy2 and NumPy.3 We surveyed available open source astrometric libraries and compare ICRS coordinate to observation transforms using recent releases of C source code and Python wrappers from the IAU Standard of Fundamental Astronomy4 (SOFA), against those using the US Naval Observatory Vector Astrometry Software5 (NOVAS). The selection of an underlying operating system with long term support is also an important aspect of maintaining a working telescope control system. The installation and operation of the libraries under both Linux Ubuntu LTS (Long Term Support) and Windows 10 are explored.
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