Optical measurements and relative trajectory determination of colocate geostationary satellites

The paper deals with the analysis of trajectory determination of collocate geostationary satellite through optical devices. Has been considered as study case a formatioo of Eutelsat satellites that has been photographed during observation campaign of June-July 2013 carried out from the space debris observatory of the University of Rome "La Sapienza". In particular the images have been used to perform accurate orbit determination and residuals with respect to Two Line Elements have been achieved. These kind of system for trajectory determination represent a valuable substitute to active orbit determination in case of failure and are of absolute importance for the operative life of the spacecraft in case of closing approach with unknown or debris orbiting objects that usually have not the manoeuvring capability. Copyright© (2013) by the International Astronautical Federation.