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The COMPASS tokamak, a divertor device with clear H-mode and ITER-relevant geometry, has been re-installed in IPP Prague after its transport from CCFE in UK. The first plasma was achieved in December 2008. Many new diagnostic tools with both high temporal and spatial resolutions have been developed to address the scientific programme of COMPASS focused on H-mode physics and pedestal investigations. In the paper, an overview of existing and in near future planned diagnostics (magnetic, spectroscopy, microwave, probe and beam/particle) on COMPASS is given including their basic technical specifications and achievements.

The integrated spectroscopic system for visible plasma radiation, soft X-ray, and bolometric measurements has been designed for the COMPASS tokamak. This diagnostic allows tomographic reconstruction at a few microseconds time base and features an improved spatial resolution about 1 cm in the pedestal region, where the highest gradient of plasma pressure drives turbulent structures and their propagation towards the wall. In combination with other developed diagnostics on COMPASS, it represents an ideal tool for a measurement and characterization of these radiating plasma structures, which are responsible for an extremely high particle/energy transport across magnetic field. The design of the new integrated multi-channel spectroscopic diagnostics is reviewed and corresponding technical challenges are described. Additionally, the methods, which will be used for data processing, are briefly mentioned and target physics is discussed.

A new Thomson scattering diagnostic system has been designed and is being built now on the COMPASS tokamak at the Institute of Plasma Physics ASCR in Prague (IPP Prague) in the Czech Republic. This contribution focuses on design, development, and installation of the light collection and detection system. High spatial resolution of 3 mm will be achieved by a combination of design of collection optics and connected polychromators. Imaging characteristics of both core and edge plasma collection objectives are described and fiber backplane design is presented. Several calibration procedures are discussed. The operational deployment of the Thomson scattering diagnostic is planned by the end of 2010.