Regional Symposium on Innovation in science and technology

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Development of an Interface for Estimating the GDOP Parameter in the Conceptual Design of Satellite Constellations

Authors :

Mohammad Haji Jafari¹ Fateme Sourani² Sahar Aminabadi³ Zahra Amini⁴

1- مرکز آموزش عالی بوئین زهرا 2- مرکز آموزش عالی بوئین زهرا 3- دانشگاه تهران 4- دانشگاه خواجه نصرالدین طوسی

Keywords :

Geometric Dilution of Precision (GDOP)،Satellite Navigation،User Interface،Systems Tool Kit (STK)،Positioning Accuracy

Abstract :

This study presents the development and evaluation of an automated user interface comprising a MATLAB code and simulations from Systems Tool Kit (STK) (as one of the leading software packages in orbital mechanics). The user interface aims to calculate the GDOP of various orbital scenarios in an iterative and time-saving manner, which is a common feature in the conceptual satellite constellation design step. GDOP, a key metric for positioning accuracy in satellite constellations, plays a vital role in enhancing the reliability of navigation results. in order to attain more explicit and precise results, inverse GDOP (1/GDOP) is utilized here. The research involves simulations of 2100 circular satellite constellations assuming two-body problem conditions in three altitudes—400, 800, and 1400 kilometers—and seven orbital inclinations (0° to 90° at 15° intervals) following the Walker Delta pattern. The results are validated against manually defined STK scenarios, confirming the reliability and efficiency. It can be concluded that results become more accurate versus higher altitudes, while the higher the inclination, the better the outcomes are. The developed tool demonstrates faster performance than manual methods while maintaining satisfactory performance and offers a valuable positioning and satellite navigation research solution, enabling faster and more reliable calculations.