Resumen: This paper shows the precise relative motion of different orbiters located at the geostationary region thanks to high precision astrometric coordinates, which are calculated thanks to different accurate observations taken from the Venezuelan National Observatory. These orbiters are close to each-other and present different relative motions although the magnitude of the distribution forces that act over them is the same. Thus, these orbiters must posses other intrinsic physic parameters which provokes the different observed morphological dynamic. In particular, the area-to-mass ratio could be one of them, and consequently, the main goal of this paper is to determine a reliability range for the area-to-mass ratio, that justifies the relative motion of these objects. Since a complete relative motion of the orbit is not feasible, we use realistic models to simulate the real motion of these orbiters, and we associate them an invented value for the area-to-mass ratio. Then, we use an analytical reduced model to compute the evolution of the eccentricity, considering different values for the area-to-mass ratio. Consequently, we are able to recover a reliability range for this invented parameter. In this work, it is also possible to consider the real ephemerides of objects listed in the CelesTrack database, and estimate its corresponding value for the area-to-mass ratio. Thus, this paper provides an innovative way to obtain a physical property of a space object just by observational information. Idioma: Inglés DOI: 10.1016/j.actaastro.2019.09.039 Año: 2020 Publicado en: Acta Astronautica 166 (2020), 104-112 ISSN: 0094-5765 Originalmente disponible en: Texto completo de la revista