Observing Procedure

  • Determine coronagraph in SCExAO (HRS-C mode) or you can choose non-corongraphic mode (HRS-NC mode).

  • REACH has currently 7 ports of the multicore fibers.

  • Choose two inputs to IRD from 7 ports of the multicore fibers or Laser comb.

  • You need an additional overhead time for fiber position optimization (~10 min) for each target.

  • REACH can be used simultaneously with CHARIS with any dispersion modes, but the wavelength coverage of CHARIS will be from 1850 nm to the longest wavelengths shown in the CHARIS web site.

Fiber Configuration


Examples of configuration.




Stopping the SCExAO loop

15 s

Confirming the next target and stopping the AO188 loop

40 s

Slew time

~< 8 min

Closing AO188 loop

60 s

Aligning to SCExAO

20 s

Closing SCExAO loop + flux tuning

30 s - 60 s

Setting Coronagraph, dichroics,

1 min - 2 min

Optimization of fiber coupling

~ 10 min for each target

TOTAL minus slew time

~ 15min