Remote sensing
Javad Haghshenas; Reza Sharifi Hafshejani
Volume 16, Issue 1 , March 2023, , Pages 1-9
Abstract
In this paper, a step-by-step laboratory procedure for performing a satellite's payload’s alignment measurement is presented. Four highly accurate theodolites are used along with two or more alignment corner cube to accurately extract the final attitude. Theodolites are arranged around the satellite ...
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In this paper, a step-by-step laboratory procedure for performing a satellite's payload’s alignment measurement is presented. Four highly accurate theodolites are used along with two or more alignment corner cube to accurately extract the final attitude. Theodolites are arranged around the satellite in such a way that they have a clear direct view of the alignment cubes mounted on the payload and the satellite. Two theodolites should point to the payload’s alignment cube and the other two theodolites must point to the satellite’s alignment cube. Each theodolite must see at least one other theodolite, directly. Finally, by forming the coordinates systems of the payload and satellite in the theodolites coordinate system along with using the coordinate transfer matrices, the payload alignment correction matrix will be extracted in detail. The total method accuracy is within the order of few arcseconds.
Javad Haghshenas; Mahmoud Reza Rezaei
Volume 13, Issue 3 , September 2020, , Pages 79-89
Abstract
In this paper, an accurate computational method is proposed to measure the relative accuracy of the star sensor, which does not require complex laboratory instruments. The proposed method uses the direct observation of the night sky along with the exact equations of motions of the Earth and stars to ...
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In this paper, an accurate computational method is proposed to measure the relative accuracy of the star sensor, which does not require complex laboratory instruments. The proposed method uses the direct observation of the night sky along with the exact equations of motions of the Earth and stars to measure the accuracy of the star sensors in the order of 1 arcsecond. The Classical Laboratory Measurement Procedures of the star sensor’s accuracy requires at least a sky simulator along with some auxiliary tools such as a collimator, an accurate 3 DOF Rotary table, an exact alignment instruments, and so on. The classical procedure, in addition of being complex and time-consuming, is costly, and the auxiliary tools also increase the measurement error by themselves. Identifying and eliminating these errors are more difficult process. The proposed procedure is more accurate and more reliable because the sensor is tested in its actual operating environment, i.e., the sky, rather than the simulated laboratory environment.
