SABOCA, the Submillimeter APEX Bolometer Camera, is a bolometric continuum receiver for operation in the 350 μm atmospheric window.

The first incarnation of this receiver is based on an array of 39 superconducting bolometers with SQUID (Superconducting Quantum Interference Device) amplification and multiplexing.

The receiver has been designed and assembled by the bolometer group of MPIfR in collaboration with the IPHT (Institute of Photonic Technology) of Jena, Germany. In the design of SABOCA converges the experience of the MPIfR bolometer group in the development of bolometers for astronomical applications with the expertise (consolidated over more than 15 years) of the collaborators at the IPHT in the development of state-ofthe-art superconducting devices.

The bolometer array used in SABOCA is the result of a continuous development of these new technologies over the last few years (the collaboration started in 2003) achieved with a large number of iterations in a closed-loop of theoretical studies, manufacture at IPHT and testing at MPIfR.

A prototype system has been tested in the labs at MPIfR and successfully installed and operated on APEX during the first half of May 2008 (during MPIfR observing time).

The final system had first light in October 2008 and is going to be commissioned as facility instrument for APEX already at the beginning of March 2009.

In order to be fully integrated in the APEX environment, SABOCA is provided with a hardware/software infrastructure similar to that one of LABOCA. A frontend software, running on the same frontend computer used by LABOCA, is used to control and monitor the hardware of the system (temperature monitor, SQUIDs tuning, offset removal, helium pumping, recycling and more). The backend software, also running on the same backend computer used by LABOCA, is used to collect the bolometer signals from the electronics of SABOCA and provide the TCP data stream required by the APEX control software. With the use of the same bridge computer of LABOCA, real-time digital signal processing (Fourier filtering, downsampling) of the raw data is possible, although not strictly required. All the software modules of SABOCA will provide an SCPI interface (Standard Commands for Programmable Instrumentation) to allow full remote operation of the instrument also from the telescope's control software.