TAILORING THE OBSERVATION SCENARIOS AND DATA PROCESSING TECHNIQUES FOR SUPPORTING CONJUNCTION EVENT ASSESSMENTS T. Flohrer * , B. Bastida Virgili * , H. Krag * , H. Klinkrad * , K. Merz * , T. Schildknecht + , S. Lemmens * ( * ) ESA/ESOC Space Debris Office (HSO-GR), Darmstadt, Germany. ( + ) Astronomical Institute, University of Bern, Bern, Switzerland. Email: tim.flohrer@esa.int ABSTRACT Conjunction event detection and collision risk assessment is provided by an operational service of ESA’s Space Debris Office. In order to improve the knowledge on the orbit of the chaser object and of the related uncertainties, acquiring additional tracking data may be considered for assessing the identified high risk conjunction events. Having such an improved picture not only supports decision making during collision avoidance activities. Additional tracking data may also allow to verify and validate conjunction event data provided by external services. We investigate, by means of parametric analyses, and by considering different data acquisition strategies, different sensor architectures to support conjunction event analyses. The improvement of the determined orbit vs. the reference information is used as a metric. To support the conclusions we review selected past conjunction events, where additional tracking data have been acquired.