SPHERE/IRDIS: Reference frames

SPHERE IRDIS reference frames

Calibrations are taken for the following IRDIS modes

• classical imaging ( CI )
• dual beam imaging ( DBI )
• differential polarimetric imaging ( DPI )
• long slit spectroscopy ( LSS )

The three basic IRDIS optical components are stored in the following keys:

• the Lyot stop filter wheel INS1.OPTI1.NAME (which is CLOSED for dark frames)
• the common filter wheel INS1.FILT1.NAME (with broad band filters like B_Y, B_Ks, B_H)
• dual filter wheel INS1.OPTI2.NAME
  • being CLEAR for classical imaging (CLI)
  • can be D_Y23, D_K12 and others in dual beam imaging mode (DBI)
  • show the polarimetric filters P0-90 or P45-270 in differential polarimetric imaging mode (DPI)
    

IRDIS dark and background frames:

IRDIS dark and background frames are acquired in regular time intervals for the following setups:

• DIT=2, NDIT=40
• DIT=8, NDIT=25
• DIT=30, NDIT=15

IRDIS dark frames use the setup INS1.OPTI1.NAME=CLOSED, while IRDIS background calibration frames use INS1.OPT1.NAME=OPEN and become dependent on the dual beam filter wheel.

dark
Lyot stop: INS1.OPTI1.NAME	CLOSED	CLOSED	CLOSED
common: INS1.FILT.NAME	any	any	any
dual filter wheel: INS1.OPTI2.NAME	any	any	any
detector setup DET.SEQ1.DIT_DET.NDIT	2.0_40	8.0_25	30.0_15
dark
raw files * [all are 8.1 MB]	DIT=2	DIT=8	DIT=30
headers	hdr	hdr	hdr
products
background H
Lyot stop: INS1.OPTI1.NAME	OPEN	OPEN	OPEN
common: INS1.FILT.NAME	B_H	B_H	B_H
dual filter wheel: INS1.OPTI2.NAME	D_H23	D_H23	D_H23
detector setup DET.SEQ1.DIT_DET.NDIT	2.0_40	8.0_25	30.0_15
background H
raw files * [all are 8.1 MB]	DIT=2	DIT=8	DIT=30
headers	hdr	hdr	hdr
products
background K
Lyot stop: INS1.OPTI1.NAME	OPEN	OPEN	OPEN
common: INS1.FILT.NAME	B_Ks	B_Ks	B_Ks
dual filter wheel: INS1.OPTI2.NAME	D_K12	D_K12	D_K12
detector setup DET.SEQ1.DIT_DET.NDIT	2.0_40	8.0_25	30.0_15
background K
raw files * [all are 8.1 MB]	DIT=2	DIT=8	DIT=30
headers	hdr	hdr	hdr
products

IRDIS flat frames:

IRDIS flat frames are acquired for the four modes CI, DBI, DPI and LSS

• CI: dual beam filter wheel = CLEAR, Lyot stop = OPEN
• DBI: dual beam filter is one of D_Y23, D_J23, D_H23, D_K12
• DPI: dual beam filter is P0-90 or P45-127
• LSS: this mode is calibrated with H-band imaging flats, spectroscopic flats are shown here only for reasons of complenes and might be taken out again.

The irdis flat template for CI and DBI currently (2015-04) takes five raw frames with increasing exposure time, of which only the highest counts raw frame without stop is shown. For LSS two raw frames are taken, of which only the second frame is shown.

CI
Lyot stop: INS1.OPTI1.NAME	OPEN	OPEN	OPEN	OPEN
common: INS1.FILT.NAME	B_Y	B_J	B_H	B_Ks
dual filter wheel: INS1.OPTI2.NAME	CLEAR	CLEAR	CLEAR	CLEAR
CI imaging flat
raw files * [all are 8.1 MB]	B_Y	B_J	B_H	B_Ks
headers	hdr	hdr	hdr	hdr
products
DBI
Lyot stop: INS1.OPTI1.NAME	OPEN	OPEN	OPEN	OPEN
common: INS1.FILT.NAME	B_Y	B_J	B_H	B_Ks
dual filter wheel: INS1.OPTI2.NAME	D_Y23	D_J23	D_H23	D_K12
DBI imaging flat
raw files * [all are 8.1 MB]	D_Y23	D_J23	D_H23	D_K12
headers	hdr	hdr	hdr	hdr
products
LSS
Lyot stop: INS1.OPTI1.NAME	CLEAR	CLEAR	CLEAR	CLEAR
common: INS1.FILT.NAME	PRI_LRS	PRI_LRS	GRI_MRS	GRI_MRS
INS.COMB.ICOR	N_S_LR_OPEN	N_S_LR_WL	N_S_MR_OPEN	N_S_MR_WL
DPR.TECH	SPECTRUM	SPECTRUM, CORONOGRAPHY	SPECTRUM	SPECTRUM, CORONOGRAPHY
LSS imaging flats
raw files * [all are 8.1 MB]	PRI	PRI	GRI	GRI
headers	hdr	hdr	hdr	hdr
products

* download fits files with "save link as ..."

 

 

IRDIS optical distortion frames:

IRDIS optical distortion frames are acquired for the three modes CI, DBI, DPI

• CI: dual beam filter wheel = CLEAR
• DBI: dual beam filter is one of D_Y23, D_J23, D_H23, D_K12
• DPI: dual beam filter is P0-90 or P45-135

All IRDIS optical distotion frames look the same. They show the same pinhole mask ( INS4.OPTI5.NAME = GRID). For this reason only one raw frame is shown.

any mode CI, DBI, DPI
INS4.OPTI5.NAME	GRID
common: INS1.FILT.NAME	any
dual filter wheel: INS1.OPTI2.NAME	any
any
raw files * [all are 8.1 MB]	B_Y
headers	hdr
products

* download fits files with "save link as ..."