Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 56 3 2024 05 21 Study on Angles-only Initial Orbit Determination methods and development of a method suitable for optical observation for LEO Study on Angles-only Initial Orbit Determination methods and development of a method suitable for optical observation for LEO 395 410 5497 10.22060/mej.2024.21373.7439 FA Abolghasem Naghash Faculty of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran 0000-0001-7776-7662 Mohammadreza Zafari Faculty of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran 0009-0007-7714-7202 Taleb Abdollahi Iranian Space Research Center, Tehran, Iran Journal Article 2022 05 06 <span style="letter-spacing: .05pt;">The need to determine the orbit of satellites is inevitable, this orbit determination is done by signal, radar or optical methods, which according to the country's capabilities for this issue, we turned to the optical method, or in other words, Angles-only methods. In this article, we examined a variety of methods for Angles-only Initial Orbit Determination and finally found the Gaussian method suitable for our purpose. The Gaussian method has different approaches to the answer, and we developed an orbit determination with a new approach that aimed to eliminate the estimates and finally presented an extended method without any estimates. To test this method, a two-body simulation was performed and its error-free results indicate the correct development and accurate implementation of the method. Also, for the case with complete Perturbation and noise of more than 3arcsec, in comparison between this method and other classical methods and other articles, we find that the accuracy of this method for IOD with optical observation has better results or at the level of new IOD methods.</span> <span style="letter-spacing: .05pt;">The need to determine the orbit of satellites is inevitable, this orbit determination is done by signal, radar or optical methods, which according to the country's capabilities for this issue, we turned to the optical method, or in other words, Angles-only methods. In this article, we examined a variety of methods for Angles-only Initial Orbit Determination and finally found the Gaussian method suitable for our purpose. The Gaussian method has different approaches to the answer, and we developed an orbit determination with a new approach that aimed to eliminate the estimates and finally presented an extended method without any estimates. To test this method, a two-body simulation was performed and its error-free results indicate the correct development and accurate implementation of the method. Also, for the case with complete Perturbation and noise of more than 3arcsec, in comparison between this method and other classical methods and other articles, we find that the accuracy of this method for IOD with optical observation has better results or at the level of new IOD methods.</span> https://mej.aut.ac.ir/article_5497_bdcc41211aa62a8f10f26d1a2d1727bf.pdf