Preflight calibration and testing of EUSO-SPB in the lab and the desert

The Extreme Universe Space Observatory on a super pressure balloon (EUSO-SPB) instrument is a pathfinder for space based cosmic ray fluorescence detectors. It is in preparation to be launched from Wanaka, New Zealand by NASA with a target launch date of 25th of March 2017. The optical system of the instrument consists of 2 Fresnel lenses. The focal surface is a camera with 2304 pixel and a time resolution of 2.5 $\mu$s build up with a modular design. The lenses and the camera where separately characterized in the laboratory. Before using the instrument for a full scale test in the field, a flat fielding was performed in the lab as well. The field tests were performed in the west Utah desert at the Telescope Array (TA) site in September 2016. The test included star observation and background measurements. An absolute calibration with an 365 nm UV-LED and with a laser "test beam" system. Laser tracks were measured at a distance of 24 km in various geometries to obtain a full characterization of the detector capability to measure cosmic rays. We will describe briefly the test system and the performed test and present the results of the laboratory and field tests of EUSO-SPB.