Table 4: Control loop performance and optimum repetition frequencies (0 Hz means that no control loop is used) as simulated on a 100 s observation sequence, for the GENIE instrument working on the 8-m Unit Telescopes (UT) at the VLTI (results taken from Paper I) and the ALADDIN instrument at Dome C. The observations are carried out in the L band for a Sun-like G2V star located at 20 pc using either the 47-m UT2-UT3 baseline at the VLTI (waveband: 3.5-4.1 $\mu$ m) or a baseline length of 20 m for ALADDIN (waveband: 3.1-4.1 $\mu$ m). The goal performance for exozodiacal disc detection discussed in Paper I appears in the last column. The total null is the mean nulling ratio including both the geometric and instrumental leakage contributions. The last line gives the standard deviation of the instrumental nulling ratio for this 100 s sequence (note that we give here the standard deviation of the mean instrumental nulling ratio computed on the whole time sequence, which is more representative than the frame-to-frame deviation presented in Paper I).
GENIE - UT ALADDIN

Worst case Best case Worst case Best case Goal

Piston 17 nm @ 20 kHz 6.2 nm @ 13 kHz 14 nm @ 3 kHz 10 nm @ 2 kHz <4 nm

Inter-band disp. 17 nm @ 200 Hz 4.4 nm @ 300 Hz 7.0 nm @ 0 Hz 7.0 nm @ 0 Hz <4 nm

Intra-band disp. 4.1 nm @ 200 Hz 1.0 nm @ 300 Hz 7.4 nm @ 0 Hz 7.4 nm @ 0 Hz <4 nm

Tip-tilt 11 mas @ 1 kHz 11 mas @ 1 kHz 9 mas @ 1 kHz 9 mas @ 1 kHz (see intensity)

Intensity mismatch 4% @ 1 kHz 4% @ 1 kHz 1.2% @ 0 Hz 1.2% @ 0 Hz <1%

Total null $9.7\times 10^{-4}$ $6.2\times 10^{-4}$ $2.9\times 10^{-4}$ $2.2\times 10^{-4}$ f(baseline)

Instrumental null $5.0\times 10^{-4}$ $1.5\times 10^{-4}$ $2.0\times 10^{-4}$ $1.3\times 10^{-4}$ 10^-5

rms null $4.5\times 10^{-6}$ $2.0\times 10^{-6}$ $5.0\times 10^{-6}$ $3.5\times 10^{-6}$ 10^-5

**Table 4:** Control loop performance and optimum repetition frequencies (0 Hz means that no control loop is used) as simulated on a 100 s observation sequence, for the GENIE instrument working on the 8-m Unit Telescopes (UT) at the VLTI (results taken from Paper I) and the ALADDIN instrument at Dome C. The observations are carried out in the L band for a Sun-like G2V star located at 20 pc using either the 47-m UT2-UT3 baseline at the VLTI (waveband: 3.5-4.1 $\mu$ m) or a baseline length of 20 m for ALADDIN (waveband: 3.1-4.1 $\mu$ m). The goal performance for exozodiacal disc detection discussed in Paper I appears in the last column. The total null is the mean nulling ratio including both the geometric and instrumental leakage contributions. The last line gives the standard deviation of the instrumental nulling ratio for this 100 s sequence (note that we give here the standard deviation of the mean instrumental nulling ratio computed on the whole time sequence, which is more representative than the frame-to-frame deviation presented in Paper I).
	GENIE - UT	ALADDIN
	Worst case	Best case	Worst case	Best case	Goal
Piston	17 nm @ 20 kHz	6.2 nm @ 13 kHz	14 nm @ 3 kHz	10 nm @ 2 kHz	<4 nm
Inter-band disp.	17 nm @ 200 Hz	4.4 nm @ 300 Hz	7.0 nm @ 0 Hz	7.0 nm @ 0 Hz	<4 nm
Intra-band disp.	4.1 nm @ 200 Hz	1.0 nm @ 300 Hz	7.4 nm @ 0 Hz	7.4 nm @ 0 Hz	<4 nm
Tip-tilt	11 mas @ 1 kHz	11 mas @ 1 kHz	9 mas @ 1 kHz	9 mas @ 1 kHz	(see intensity)
Intensity mismatch	4% @ 1 kHz	4% @ 1 kHz	1.2% @ 0 Hz	1.2% @ 0 Hz	<1%
Total null	$9.7\times 10^{-4}$	$6.2\times 10^{-4}$	$2.9\times 10^{-4}$	$2.2\times 10^{-4}$	f(baseline)
Instrumental null	$5.0\times 10^{-4}$	$1.5\times 10^{-4}$	$2.0\times 10^{-4}$	$1.3\times 10^{-4}$	10^-5
rms null	$4.5\times 10^{-6}$	$2.0\times 10^{-6}$	$5.0\times 10^{-6}$	$3.5\times 10^{-6}$	10^-5

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