ESA's INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) will be launched in October 2002. Its two main instruments are the imager IBIS and the spectrometer SPI. Both employ coded apertures to obtain directional information on the incoming radiation. SPI's detection plane consists of 19 hexagonal Ge detectors, its coded aperture has 63 tungsten-alloy elements of 30 mm thickness. At MPE, the SPI Imaging Test Setup (SPITS) has been built to help determine the imaging capabilities of such a coded aperture system. SPITS consists of the SPI coded mask and two SPI-identical Ge detectors on all XY-table which allows to move them to cover the 19 Ge detector positions. Here, we combine results from the SPI flight-model calibration (radioactive sources up to 2.7 MeV at tip to 125 m illuminate the mask-detector array) with SPITS measurements (gamma-ray lines up to 9 MeV from radioactive sources and proton-capture reactions at 9 m) to determine the system's imaging performance, in particular point-source location capability and angular resolution. The imaging performance depends critically on the quality of the instrument response function, generated from simulations. We demonstrate the importance of combining several instrument pointings, and show that the capability for separating two point, sources is equal to or better than 1 at 1 MeV, at least for high signal-to-noise. The point-source location capability is equal to or better than 10' under the same conditions.
