The seismic high-resolution crosshole imaging system consists of the borehole sparker source SBS1000 generating P-waves and the digital hydrophone string BHC1000 as receiver. The system can be used for tomography surveys up to 1000 m depth. High-resolution P-wave tomographic investigations between boreholes is essential for preliminary investigations for large constructions projects, for mining explorations, for nuclear end storage investigations, CO2 monitoring and geothermal projects. The high voltage capacitors (charging up to 3200 V) inside the SBS1000 probe allows the release of high frequent Pwaves with an excellent signal repeatability and a wide frequency range up to several kilohertz. The power supply is ensured by the surface control unit which is connected by a standard 4-conductor logging cable to the SBSB1000 probe by a GO-4 cable head at the top and sends out a TTL time break trigger. The hydrophone string is fully digitized and consists of a downhole digitization unit which communicates with the BHC1000 surface unit and 24 hydrophones moulded to a multicore cable. The tool can be connected directly to the laptop. Using the associated acquisition software data can be visualized and stored. No further seismograph is needed.The 3D imaging software GeoTomCG is a tomographic inversion program for traveltime and amplitude data sets and completes the system.