FCU Overview

The Field Camera Unit (FCU) is one of the main scientific instruments of the WSO-UV.

The main task of the FCU is to obtain high resolution images and low resolution spectra in Far- and Near- Ultraviolet.

The contributors to its design and construction are Lavochkin Association as WSO-UV prime contractor, INASAN as prime contractor for payload, and IKI RAS,as prime contractor for the FCU.

Spain contributes to the FCU as industrial supplier of the FUV detector and with the Universidad Complutense of Madrid (UCM) as Scientific supervisor.

The main drivers for the FCU design are: 

-          High radiometric efficiency in the FUV range, minimizing the number of optical elements involved.

-          Low degradation of the spatial resolution.

-          Adequate PSF sampling to guarantee accurate astrometric and photometric measurements. The optical design shall provide the necessary magnification for each detector.

-          Wide field of view to increase the scientific outcome of the mission.

-          Simplified optical scheme, compact design.


FCU main parts

FCU consists of:

-          Optical-mechanical unit located at T-170M telescope optical bench

-          Channel control unit (CCU) located at External panel

-          System control unit (SCU) located at External panel

-          Mechanisms control unit (MCU) located at External panel

-          Harness


FCU Optical elements characteristics

FUV channel based on CsI MCP detector with CMOS readout, 115-176 nm

-          Solar blind detector

-          Diffraction-limited imaging in FUV

-          High sensitivity in photon-counting mode

-          High time resolution


NUV detector based on e2V CCD cooled.

-          Wide field of view

-          High dynamic range

-          High angular resolution

-          Low resolution field spectroscopy

-          Possibility for extended spectral range: 115-1000 nm



       FCU Preliminary Layout (Jun 2017)

FCU Characteristics

FCU Operational modes 

The FCU supports different operation modes for the two channels, selected through the mode selection mechanism (MSM):

-          Imaging: the beam is directly focused on the selected channel (FUV or NUV).

-          Spectroscopy: the beam is directed to the dispersive elements, which are reflection gratings located   

       at the MSM.

-          Calibration: a shutter is used to block the light from the telescope, and the beam is directed to the

       calibration subsystem in order to take flat field images on a pixel-to-pixel basis.

-          Coronographic mode:  TBD.