SPACE SURVEILLANCE OBSERVATIONS AT THE ZIMMERWALD OBSERVATORY Martin Ploner (1) , Thomas Schildknecht (2) , Carolin Früh (3) , Alessandro Vananti (4) , Johannes Herzog (5) Astronomical Institute, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland (1) ploner@aiub.unibe.ch, (2) schildkncecht@aiub.unibe.ch, (3) frueh@aiub.unibe.ch, (4) vananti@aiub.unibe.ch, (5) herzog@aiub.unibe.ch ABSTRACT At the Zimmerwald observatory optical observations of artificial space objects are performed with the 1m Laser and Astrometric Telescope ZIMLAT and the 0.2m Small Robotic Telescope ZimSMART. While ZIMLAT is especially used for follow-up observations of newly detected small-size space debris objects, the main field of application of ZimSMART are survey observations. The goal of these observations is the built-up and maintenance of a catalogue of geostationary objects. Furthermore ZIMLAT is routinely used for unresolved space object identification by means of colour photometry and light curve measurements. This paper will highlight the space situational awareness capabilities of the Zimmerwald observatory from a technical point of view. Examples from the routine operations as well as from requests on short notice like the support of ESA during the XMM contingency operations will be given. 1 THE ZIMMERWALD OBSERVATORY The Zimmerwald Observatory is located 10km South of Berne (Switzerland). Currently optical observations are performed with the 1m Laser and Astrometric Telescope ZIMLAT (Fig. 1) and the 0.2m Small Aperture Robotic Telescope ZimSMART (Fig. 2). Both telescopes are equipped with state-of-the-art CCD cameras with low readout-noise and high quantum efficiency (Tab. 1). Table 1: Comparison between technical data of ZIMLAT and of ZimSMART ZIMLAT (installed in 1997) is used either for laser ranging to satellites (SLR) or for optical observation of positions and magnitudes of near-Earth objects. During daytime the system operates in SLR mode only. During nighttime the available observation time is shared between SLR and CCD using negotiated priorities. The switching between the modes is done under computer control and needs less than half a minute. In addition light curves and photometric observations can be retrieved. Due to the large field of view (FOV) ZimSMART (installed in 2006) is best suited for sky surveys. The goals of these surveys are mainly to build-up and maintain a catalogue of artificial satellites and space debris objects. Figure 1: Image of ZIMLAT Figure 2: Image of ZimSMART