SAAO - South African Astronomical Observatory


TRIPOL is a three-colour imaging camera operating simultaneously in Sloan g', r' and i' bands.  It is a visiting instrument from Nagoya University that we are pleased to offer on the SAAO 0.75-m telescope from Quarter 4 of 2012.

The beam is split by two dichroics, then directed to three SBIG cameras via the fixed Sloan filters, resulting in three FITS images for each exposure (g', r' and i').  The instrument is operated from the command line, and interfaces with the TCS such that telescope positional information is written to the FITS headers.  The telescope can be slewed automatically to objects in a catalogue file stored on the instrument PC, and pointing offsets can be applied from the command line (e.g. for dithering).

Technical Specification

Detector SBIG ST-9XEI
Operating temperature -20C
Detector dimensions 512 x 512 pixels
Pixel size 20 um x 20 um
Field of view 3' x 3'
Saturation limit 65535
Gain 1.70 e-/ADU
Read noise 15 e-
Minimum exposure time 0.12 seconds
Dead time (inc. readout) 3 seconds
Filters Sloan g', r' and i'

Further information

Further information on the operation of TRIPOL can be found in the preliminary Users' Guide.  Please direct queries to nagayama(at)