BUSCA technical data


BUSCA data:
 
Number of dichroic plates 3
Detectors 3x CCD485 Lockheed Martin,  4096 x 4096 pixels with 15mue x 15mue, frontside devices, 
1 CCD485 backside thinned (in the uv channel). 
Number of pixels ca. 67 Mill. (4x 16.8 Mill.), ca. 16.8 Mill. total with 2x2 binning
Field of view 12 arcmin x 12 arcmin
Pixel size 0.176 arcsec (0.35arcsec with 2x2 binning, standard at typical seeing conditions)
CCD controller MPIA design, 4 channels maximum
CCD read out four color channels simultaneously
Read out time ca. 2:20min with 2x2 binning
Shutter: Type "Bonn Shutter", two blade, stepper motor driven
Shutter: Min. exposure time < 10ms
Shutter: Photometric performance Exposure homogeneity >99% at 100ms exposure time
Guider FOV 5.6 arcmin x 4.2 arcmin
Guider field position fixed, 8 arcmin north of camera field center
Data storage/format one FITS file for each of the four CCD frames 

 
 

Channel data:
 

channel a b c d
wavelength < 430 nm 430nm - 540nm 540nm - 730nm > 730nm
CCD 4k x 4k (thinned) 4k x 4k 4k x 4k 4k x 4k
gain [ADU/e-] 3.13585 3.03402 2.96736 2.93033
fullwell [e-] 131500 121000 155000 128500
read out noise [e-] 9.58 6.37 7.60 8.38
filter pos 1 WG 280 WG 280 WG 280 WG 280
filter pos 2 Strömgren v H beta (narrow) free free
filter pos 3 Strömgren u Strömgren b Strömgren y free
filter pos 4 free H beta (wide) free Cousins I

The values for the gain and readoutnoise are measured with the CDS-Gain of 20. To get the rela values for channel b which has normally the CDS-Gain of 50 you have to multiply the values with 2.5.